Journal articles on the topic 'Shale Mechanical properties Testing'
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1
Kalu, Ifeanyi Emmanuel, Ericmoore Jossou, Emmanuel Kwesi Arthur, Simon Ja'afaru, and Edith Yohanna Ishidi. "Characterization and Mechanical Property Measurements by Instrumented Indentation Testing of Niger Delta Oil Shale Cuttings." International Journal of Engineering Research in Africa 59 (March 15, 2022): 89–100. http://dx.doi.org/10.4028/p-2m9z7g.
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Oil shales have unstable mechanical and chemical properties, which makes their extraction for characterization and conventional mechanical testing uneasy and complex. Most often, mechanical property measurements are usually taken from core samples that are costly to extract and test using conventional testing methods. This paper presents a focused study carried out on oil shale cuttings obtained from the sidewalls of two different wellbore depths in the Niger Delta area of Nigeria. Using the X-ray Diffraction (XRD) and Scanning Electron Microscope (SEM) characterization techniques, the morphology of these shales was studied. The results obtained clearly showed the composition, bonding and variations in the morphology of the studied shale samples. Furthermore, the heterogeneity associated with these shales across varied depths were revealed. An efficient and less expensive technique compared to conventional testing methods, instrumented indentation testing (IIT) was carried out to obtain essential mechanical parameters of the shale specimen. These properties are important parameters in determining the hydrocarbon storage space of shale formations, wellbore stability, and optimization of hydraulic fracturing which is necessary for efficient drilling operations.
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Rouainia, Mohamed, Majid Goodarzi, Tom Charlton, Andrew Aplin, and Pablo Cubillas. "Assessment of the elastic response of shale using multiscale mechanical testing and homogenisation." E3S Web of Conferences 205 (2020): 04013. http://dx.doi.org/10.1051/e3sconf/202020504013.
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Robust geomechanical characterisation of shale reservoirs is necessary for safe and economic resource exploitation but there is still a lack of mechanical data on well-characterised shale, partly due to the difficulties of obtaining high quality core samples for laboratory testing. The composition of shale also presents challenges when attempting to constrain the mechanical response. Multi-scale homogenisation techniques have recently been used to predict the macroscopic behaviour of shales based on quantitative mineralogical descriptions. However, there is a considerable amount of uncertainty associated with some key inputs into these homogenisation schemes. In particular, the organic matter of shale encompasses a range of scales, from nanometre to micrometre-size material, and its mechanical properties are not well understood. Here, PeakForce Quantitative Nanomechanical Mapping (PF-QNM), a recently developed form of atomic force microscopy (AFM), is combined with nanoindentation testing to characterise the mechanical response of the organic matter and clay phases of Posidonia shale from north-west Germany. The nanoscale testing revealed a clear peak in the histograms of the reduced elastic modulus, which can be attributed to kerogen in the shale matrix. Upscaling of the mechanical properties through homogenisation showed a reasonable prediction when compared with experimental data, including capturing the inherent anisotropy of the shale response. The influence of factors such as the volume fraction of silt inclusions and the applicability of different homogenisation formulations warrant further investigation.
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Wu, Zhonghu, Yujun Zuo, Shanyong Wang, Jibin Sunwen, and Leilei Liu. "Experimental Study on the Stress Sensitivity and Influence Factors of Shale under Varying Stress." Shock and Vibration 2018 (July 11, 2018): 1–9. http://dx.doi.org/10.1155/2018/3616942.
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Shale reservoirs are characterized by extremely low permeability and high clay content. To further study the stress sensitivity of a shale reservoir, the Lower Cambrian shale in north Guizhou was utilized. Through laboratory testing, the relationships between the shale porosity and permeability and the effective stress were established, and the stress sensitivity of shale was analysed. The mechanical properties and mineral composition of this shale were studied by rock mechanics testing and X-ray diffraction. The main factors affecting the stress sensitivity were analysed. The results show that the porosity and permeability of this shale decrease with increasing effective stress; the shale reservoir permeability damage rate is 61.44 ~ 73.93%, with an average of 69.92%; the permeability stress sensitivity coefficient is 0.04867 ~ 0.05485 MPa−1, with an average of 0.05312 MPa−1; and the shale reservoir stress sensitivity is strong. Shale stress sensitivity is related to the rock mineral composition and rock mechanical properties. The higher the clay content in the mineral composition, the lower the elastic modulus of shale, the higher the compressibility, and the greater the stress sensitivity coefficient.
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Yang, Guoliang, Jingjiu Bi, Xuguang Li, Jie Liu, and Yanjie Feng. "SHPB Testing and Analysis of Bedded Shale under Active Confining Pressure." Journal of Engineering 2020 (May 12, 2020): 1–8. http://dx.doi.org/10.1155/2020/5034902.
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Shale gas is the most important new energy source in the field of energy, and its exploitation is very important. The research on the dynamic mechanical properties of shale is the premise of exploitation. To study the dynamic mechanical properties of shale from the Changning-Weiyuan area of Sichuan Province, China, under confining pressure, we used a split Hopkinson pressure bar (SHPB) test system with an active containment device to carry out dynamic compression tests on shale with different bedding angles. (1) With active confining pressure, the shale experiences a high strain rate, and its stress-strain curve exhibits obvious plastic deformation. (2) For the same impact pressure, the peak stress of shale describes a U-shaped curve with an increasing bedding angle; besides, the peak stress of shale with different bedding angles increases linearly with rising confining pressure. The strain rate shows a significant confining pressure enhancement effect. With active confining pressure, the peak strain gradually decreases as the bedding angle increases. (3) As a result of the influence of different bedding angles, the dynamic elastic modulus of shale has obvious anisotropic characteristics. Shale with different bedding angles exhibits different rates of increase in the dynamic elastic modulus with rising confining pressure, which may be related to differences in the development of planes of weakness in the shale. The results of this study improve our understanding of the behavior of bedded shale under stress.
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Alqam, Mohammad H., Hazim H. Abass, and Abdullah M. Shebatalhmad. "New insight on studying the effect of both chemical sensitivity and rock mechanical properties in shale formation to minimize wellbore instability problems." E3S Web of Conferences 205 (2020): 03012. http://dx.doi.org/10.1051/e3sconf/202020503012.
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Historically, many of the wells drilled in in shale formations have experienced a significant rig downtime due to wellbore instabilities. Most of the instability problems originated from the encountered shale formations. The objectives of this study include (1) to measure the properties governing shale strength and drilling fluid/shale interaction, and (2) to establish a reliable and efficient rock mechanical testing procedures related to wellbore stability. Preserved shale core has been recovered from shale formation and special core handling procedure was implemented. Mineral oil was used for plugging and core preservation. Rock mechanical characterization was conducted on core samples using both XRD/SEM techniques to study the core mineralogy. In addition, shale permeability was determined by two methods: flow testing and pressure transition methods. The results indicated that shale has high percentage of quartz (30-40%) which causes the shale to have high porosity and high permeability. The unconfined compressive strength of shale is very low which any drilling fluid that contains water phase further reduces. The Young’s modulus is very low which makes near wellbore deformation high. Based on the shale swelling testing, the all-oil fluid show no volume change occurred to the shale. When the same shale was exposed to the 7% KCl, about 16% increase in core volume occurred in 48 hours. This means that all samples allowed the water to flow into the shale formation.
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Minaeian, Vida, Vamegh Rasouli, and David Dewhurst. "A laboratory procedure proposed for mechanical testing of shales." APPEA Journal 54, no. 1 (2014): 337. http://dx.doi.org/10.1071/aj13034.
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The authors have developed a laboratory procedure that uses a true triaxial stress cell (TTSC) to test cubes of rock instead of cylindrical-shaped samples. In this approach, three independent stresses are applied on the rock sample, which makes it possible to simulate field-conditions. Estimation of rock failure strength and deformation properties, while applying three stresses—rather than two as in case of conventional triaxial tests—is closer to the in-situ conditions. This is specifically important for shales due to their complicated transverse isotropic structure. The present study investigates the effect of minimum and intermediate principal stresses on the strength and elastic properties of gas shales. True triaxial experiments have been carried out on cubic shale samples from the Perth Basin under constant levels of minimum stress (~3 and 6 MPa) and varying magnitudes of intermediate principal stress (~3–40 MPa). Both minimum and intermediate stresses affect the rock strength through a non-linear trend. The behaviour of shales elastic modulus (E) with respect to varying σ2 tends to be similar to that of rock compressive strength. Poisson’s ratio in two directions along minimum and intermediate principal stresses (V13 and V12) does not show a simple dependency on the intermediate stress over the applied stress range. Finally, the observation of post-failure specimens revealed a significant influence of stress anisotropy on the failure mode, which evolves from dual to multiple shear faults.
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Guo, Yintong, Chunhe Yang, Lei Wang, and Feng Xu. "Effects of Cyclic Loading on the Mechanical Properties of Mature Bedding Shale." Advances in Civil Engineering 2018 (2018): 1–9. http://dx.doi.org/10.1155/2018/8985973.
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We investigated the mechanical properties of mature bedding shale under cyclic loading conditions, with an application to the design of hydraulic fracturing in shale gas wells. Laboratory experiments were conducted on shale samples under two principal loading orientations. Testing results showed that accumulated fatigue damage occurs in a three-stage process. Analysis of fatigue damage at different maximum stress levels shows that fatigue life increases as a power-law function with maximum stress decreasing. And the maximum stress significantly affects the fatigue life. Further, the elastic part of shale rock deformation was recovered in the unloading process, whereas the irreversible deformation remained. The irreversible deformation, growth trend, and accumulation of the total fatigue were directly related to the fatigue damage. This process can be divided into 3 stages: an initial damage stage, a constant velocity damage stage, and an accelerated damage stage, which accounted for about one-third of the fatigue damage. Shale rock is a nonhomogeneous material, and the bedding is well developed. Its fatigue life differs greatly in two principal loading orientations, even under the same loading conditions. All of these drawn conclusions are of great importance for design of hydraulic fracturing in shale gas wells.
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Meng, Lu Bo, Tian Bin Li, Liang Wen Jiang, and Hong Min Ma. "Experimental Study on the Influence of Temperature on Shale Mechanical Properties under Conventional Triaxial Compression." Advanced Materials Research 250-253 (May 2011): 1452–55. http://dx.doi.org/10.4028/www.scientific.net/amr.250-253.1452.
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High temperature conventional triaxial compression test of shale are carried out by the MTS815 servo-controlled testing machine, based on the experimental results, the relationships between temperature and shale peak strength, elastic modulus, Poisson's ratio, cohesion, internal friction angle are investigated. Although the experimental results are discrete comparatively, the general law is obvious. When the confining pressure imposed on shale is constant and the temperature changes form 25°C to 120°C, with the increasing of the temperature, the triaxial compression strength, shear strength gradually increase, while average elastic modulus, Poisson's ratio has a slightly decrease. The thermal stress generated by the high temperature plays a role to accommodate the deformation and the function of preventing crack propagation, thus the bearing capacity of shale samples are strengthened. But the influence of temperature on shale mechanical properties mutates when the temperature is at 80°C. Shale peak strength dramatically decreased, average elastic modulus decreased slightly, and Poisson's ratio also increased slightly, which indicated that at 80°C, different thermal expansivity of mineral particles of shale may cause cross-grain boundary thermal expansion incongruous, creating additional thermal stress, thus the sample’s bearing capacity decreased.
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Liu, Qing-You, Lei Tao, Hai-Yan Zhu, Zheng-Dong Lei, Shu Jiang, and John David McLennan. "Macroscale Mechanical and Microscale Structural Changes in Chinese Wufeng Shale With Supercritical Carbon Dioxide Fracturing." SPE Journal 23, no. 03 (December 14, 2017): 691–703. http://dx.doi.org/10.2118/181369-pa.
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Summary Waterless fracturing for shale-gas exploitation using supercritical carbon dioxide (scCO2) is both effective and environmentally friendly, and has become an extensive research topic. Previous researchers have focused on the chemical and physical properties and microstructure of sandstone, carbonate, and shale caprock, rather than on the properties of shale-gas formations. The macroscale mechanical properties and microscale fracture characteristics of Wufeng Shale exposed to scCO2 (at greater than 31.8°C and 7.29 MPa) are still not well-understood. To study the macroscale and microscale changes of shale subjected to scCO2, we obtained Chinese Wufeng Shale crops (Upper Ordovician Formation) from Yibin, Sichuan Basin, China. The shale samples were divided into two groups. The first group was exposed to scCO2, and the second group was exposed to nitrogen (N2). Scanning-electron-microscope (SEM) and X-ray-diffraction (XRD) images were taken to study the original microstructure and mineral content of the shale. To study the macroscale mechanical changes of Wufeng Shale immersed in scCO2 or N2 for 10 hours, triaxial tests with controlled coring angles were conducted. SEM and XRD images were taken after the triaxial tests. In the SEM images, tight bedding planes and undamaged minerals (with sharp edges and smooth surfaces) were found in N2-treated samples both before and after testing, indicating that exposure to N2 did not affect the microstructures. However, the SEM images for the microstructure scCO2-treated samples before and after testing were quite different. The bedding planes were damaged, which left some connected microfractures and corrosion holes, and some mineral types were broken into small particles and left with uneven mineral surfaces. This shows that scCO2 can change rock microstructures and make some minerals (e.g., calcite) fracture more easily. The complex microscale fractures and the decrease in strength for scCO2-treated shale aid the seepage and gathering of gas, enhancing shale-gas recovery. Knowledge of the multiscale physical and chemical changes of shale exposed to scCO2 is not only essential for scCO2 fracturing, but it is also important for scCO2 jets used to break rock and for the geological storage of CO2.
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Nichols Jr., Thomas C., Donley S. Collins, and Richard R. Davidson. "In situ and laboratory geotechnical tests of the Pierre Shale near Hayes, South Dakota—A characterization of engineering behavior." Canadian Geotechnical Journal 23, no. 2 (May 1, 1986): 181–94. http://dx.doi.org/10.1139/t86-028.
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A geotechnical investigation of the Pierre Shale near Hayes, South Dakota, was conducted by the U.S. Geological Survey as a basis for evaluating problems in deep excavations into that formation. The physical and mechanical properties of the shale were determined through use of core holes drilled to a maximum depth of 184 m. In situ borehole determinations included a gravimeter survey, pressuremeter testing, thermal profile measurements, and borehole velocity measurements. Onsite and offsite laboratory measurements included rebound measurements, sonic velocity measurements of shear and primary waves, X-ray mineralogy and major element determinations, size analyses, fracture analyses, fabric analyses, and determination of thermal properties.Below 15–22 m, the shale is an unweathered, saturated, overconsolidated, underpressured clay shale with a clay-mineral content ranging between 50 and 100%, dominantly composed of mixed-layer illitic smectites. The physical and mechanical properties vary widely. The variation is related to the clay mineral content (especially in bentonite zones), a large transverse mechanical anisotropy, and zones of fractures and microfractures, which may result from rebound caused by erosion. These may contribute to slope instability over large areas. The thermal and mechanical properties change markedly if the shale is permitted to dry out. The state of stress and overconsolidation appear to be functions of the depositional and erosional history of the deposit. Both are markedly affected by the large fracture zones. The properties of the clay shale indicate problems that may be encountered in excavation and use of deep underground facilities. Key words: anisotropy, characterization, clay shale, consolidation state, physical properties, rebound, relaxation, stress state, thermal properties.
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Al-Shurafat, Alaa, and Raid Banat. "Properties of Oil Shale Ash Filled Polypropylene Composite Material: Mechanical and Physical Characterization." Asian Journal of Chemistry 33, no. 9 (2021): 2175–81. http://dx.doi.org/10.14233/ajchem.2021.23324.
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The outcome of oil shale ash (OSA) filler addition on the mechanical, morphological, thermal and water uptake properties of the polypropylene (PP) matrix was investigated. The test specimens were prepared with various ratios of the mixtures that contain OSA and polypropylene in the following weight percentages: 0%, 10%, 20%, 30% and 40% OSA in polymer matrix. Composites specimens were produced by using a co-rotating twin screw extruder and a thermal press machine. The properties of the polymer composite specimens were characterized by using a universal testing machine (WDW-5) and izod impact testing machine (FI-68). The morphology of the composite samples was also characterized by using the scanning electron microscopy (SEM). Impact strength and Young’s modulus of the OSA/PP composite formulations were consistently improved on OSA inclusion. On the other hand, addition of OSA to pure polypropylene had consistently reduced the tensile stress at yield, tensile stress at rupture, tensile strain at yield and tensile strain at break. Adding OSA to polypropylene decreased the maximum flexural stress and flexural strain of maximum force. The observed SEM confirmed that the addition of OSA to pure polypropylene resulted in a significant increase in its agglomerates and filler pullout. Differential scanning calorimetry (DSC) results confirmed the addition of the OSA to pure polypropylene resulted in a significant decrease in normalized heat of crystallization, normalized enthalpy of melting. Where the degree of the crystallinity (Xc) of polymer composite decreased from 59% to 34% for 0% and 40% OSA addition, respectively. While melting temperature (Tm) of the composite did not change (167 °C) the crystallization temperature (Tc) increased from 116.6 °C to 127.1 ºC for 0% to 40% OSA addition, respectively. Water uptake, however, demonstrated different behaviour. The initial addition of OSA to polypropylene increased the water uptake property up to 4% for the 40% filler addition. The results of this study demonstrated that the OSA could be used as reinforcement material for polypropylene, as long as good mechanical properties and homogeneous morphology obtained.
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Crisci, Eleonora, Alessio Ferrari, and Lyesse Laloui. "Discussion on “Experimental Deformation of Opalinus Clay at Elevated Temperature and Pressure Conditions: Mechanical Properties and the Influence of Rock Fabric” of Schuster, V., Rybacki, E., Bonnelye, A., Herrmann, J., Schleicher, A.M., Dresen, G." Rock Mechanics and Rock Engineering 55, no. 1 (October 5, 2021): 463–65. http://dx.doi.org/10.1007/s00603-021-02654-1.
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AbstractThe testing procedure and results on saturated samples of Opalinus Clay in the work of Schuster et al. (Rock Mech Rock Eng https://doi.org/10.1007/s00603-021-02474-3, 2021) were conducted and presented using strain rates two to four orders of magnitudes higher than the rates needed to allow pore pressure equilibrium in the material, both in drained and undrained conditions. This leads to an erroneous estimation of the mechanical properties in saturated conditions. We discuss this aspect in the context of shale testing. We also discuss the effect of drying-induced fissuring on the mechanical properties of geomaterials tested in dry conditions.
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Crisci, Eleonora, Alessio Ferrari, and Lyesse Laloui. "Discussion on “Experimental Deformation of Opalinus Clay at Elevated Temperature and Pressure Conditions: Mechanical Properties and the Influence of Rock Fabric” of Schuster, V., Rybacki, E., Bonnelye, A., Herrmann, J., Schleicher, A.M., Dresen, G." Rock Mechanics and Rock Engineering 55, no. 1 (October 5, 2021): 463–65. http://dx.doi.org/10.1007/s00603-021-02654-1.
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AbstractThe testing procedure and results on saturated samples of Opalinus Clay in the work of Schuster et al. (Rock Mech Rock Eng https://doi.org/10.1007/s00603-021-02474-3, 2021) were conducted and presented using strain rates two to four orders of magnitudes higher than the rates needed to allow pore pressure equilibrium in the material, both in drained and undrained conditions. This leads to an erroneous estimation of the mechanical properties in saturated conditions. We discuss this aspect in the context of shale testing. We also discuss the effect of drying-induced fissuring on the mechanical properties of geomaterials tested in dry conditions.
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Hull, Katherine L., Younane N. Abousleiman, Yanhui Han, Ghaithan A. Al-Muntasheri, Peter Hosemann, S. Scott Parker, and Cameron B. Howard. "Nanomechanical Characterization of the Tensile Modulus of Rupture for Kerogen-Rich Shale." SPE Journal 22, no. 04 (February 13, 2017): 1024–33. http://dx.doi.org/10.2118/177628-pa.
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Summary In the past decade, chemical, physical, and mechanical characterization of source-rock reservoirs has moved toward micro- and nanoscale testing and analyses. Nanoindentation is now widely used in many industrial and university laboratories to measure stiffness and strength as well as other mechanical properties of shales. However, to date, tensile failures of shales have not been studied at the micro- or nanoscale. In this work, a scanning electron microscope (SEM) coupled with a focused ion beam (FIB) and a special nanoindenter (NI) testing configuration (SEM-FIB-NI) is used to bring organic-rich shale samples (preserved Woodford shale from a wellsite in Ada, Oklahoma, USA) to failure in tension. Microcantilever beam geometries were milled and loaded to failure in tension while monitoring in situ with SEM. The force-displacement curves were generated while videos recording in-situ real-time displacements and failures were collected simultaneously. The microcantilever beam tests of this composite natural material demonstrate linear elastic behavior followed by elastic/plastic yield before complete failure. This behavior was clearly observed to correlate with the amount of organic matter (OM) at the fractured surface of the microcantilever beam supports. Energy-dispersive X-ray spectroscopy (EDS) analyses were conducted along the prepared microbeam samples before loading. In addition, post-failure EDS analysis was performed on the resulting fractured faces of the failed microbeams, and the correlation between tensile behavior and shale OM content was shown. Large tensile moduli of rupture, or moduli of toughness, were associated with high OM, or kerogen, present at the failed supports of the kerogen-rich-shale (KRS) microcantilever beams. The moduli of toughness as a measure of work or energy needed to bring these samples into tensile failure were ten times less when OM was missing or barely present at the support, in terms of shale microbeam volume.
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Ao, Xiang, Jiren Tang, Hai Qu, and Zuping Xiang. "Shale Permeability under Shale Components’ Thermal Swelling." Geofluids 2021 (May 11, 2021): 1–7. http://dx.doi.org/10.1155/2021/9930241.
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Permeability is one of the most fundamental reservoir rock properties required for modeling hydrocarbon production. However, shale permeability is not yet fully understood because of the high temperature of shale reservoirs. The third thermal stress that is caused by temperature change will decrease the permeability of shale. In this work, a theoretical model has been derived to describe the permeability of shale considering the third thermal stress; the principles of thermodynamics and the mechanics of elasticity have been employed to develop this model. The elastic modulus parameters of the shale were measured, along with Poisson’s ratio, as required. Lastly, the permeability of shale was tested by transient pulse-decay. Isothermal flow experiments were carried out at 303, 313, 323, and 333 K to assess the effects of shale expansion and deformation on shale permeability caused by the third thermal stress. The permeability of shale samples, as predicted by the model, was found to agree well with experimental observations. The model may provide useful descriptions of the gas flow in shale. The correction accuracy of the permeability was found to increase at lower permeability. However, the development of completely predictive models for shale permeability will require additional experimental data and further testing.
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Hamzah, Noorfaizah, and Nur’Ain Mat Yusof. "Characterization of Tropical Kenny Hill Weathered Sandstone using Non-Disruptive Testing of Pundit and Resistivity Testing." Journal of Mechanical Engineering 19, no. 2 (April 15, 2022): 233–49. http://dx.doi.org/10.24191/jmeche.v19i2.19791.
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Rock characterization of tropical Kenny Hill weathered sandstone have been an effort to be explored by using non-disruptive testing of pundit and resistivity testing to undertake sustainability issues and providing technical approach in exploration of weak rock materials solving. The purpose of this research is to determine the relationship between resistivity and uniaxial compressive strength of the most problematic rock type in Malaysia, namely Kenny Hill weathered sedimentary rocks, more usually referred to as sandstone. According to earlier study, sandstone has degraded in quality and has a tendency to disintegrate due to the tropical climate. Sandstone has a higher strength feature as compared to shale from Bandar Nusa Rhu, Shah Alam. Series of uniaxial compression were carried out to obtain the strength for rock samples. The strength properties of weathered sandstone are studied to quantify the weathering impact to these materials. Resistivity test and Pundit test were laboratory method conducted on the rock samples for verification of the correlation between resistivity and uniaxial compression. Results from the test were analyzed and their relationship with weathering grade was established. It signifies that sandstone strength increasing with the weathering grade.
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Eaton-Evans, J., J. M. Dulieu-Barton, E. G. Little, and I. A. Brown. "Observations during mechanical testing of Nitinol." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 222, no. 2 (February 1, 2008): 97–105. http://dx.doi.org/10.1243/09544062jmes797.
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Superelastic and shape memory capabilities of Nitinol are strongly dependent on the alloy composition, its heat treatment, and mechanical deformation history. The current article presents a review of the behaviour of Nitinol and describes a characterization study conducted to determine the mechanical properties of the material, both by means of differential scanning calorimetry (DSC) and by mechanical testing at a range of temperatures. Values for key transformation temperatures are found using both techniques. It is concluded that mechanical deformation during sample preparation for DSC measurements may have led to material property modifications and hence erroneous phase transformation temperature values. It is shown that mechanical testing can provide a means of benchmarking DSC data.
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Utepov, Ye B. "EFFECT OF THE SHAPE AND STRUCTURE OF MATURITY SENSOR’S PLASTIC HOUSING ON ITS PHYSICO-MECHANICAL PROPERTIES." Eurasian Physical Technical Journal 18, no. 3 (37) (September 24, 2021): 83–87. http://dx.doi.org/10.31489/2021no3/83-87.
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This paper presents how the shape and physical structure of the connections affect the performance of the housing of maturity sensor. A two parts rectangular and a keg-shaped cylindrical configurations of plastic housings were sequentially tested for water, shock and load resistance. The tests revealed the weak ingress and shock resistance of the rectangular housing, in comparison with cylindrical one, where no serious defects were identified. Both types of housings performed well during the compression tests on all three sides, showing the bearing capacities from 0.6 to 2.11 kPa, which are equivalent to 65.3 and 165.3 kg of human mass. Based on the results, the study demonstrates an easy-to-handle workflow for generic testing and evaluation of maturity sensors housing. The proposed workflow may be applicable for other types of small-scaled electronic devices.
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Tehrani, Fariborz M., Nazmieh A. Masswadi, Nathan M. Miller, and Arezoo Sadrinezhad. "Experimental Investigation of Dynamic Properties of Fiber-Reinforced Tire-Derived Lightweight-Aggregate Concrete." European Journal of Engineering and Technology Research 5, no. 6 (June 15, 2020): 702–7. http://dx.doi.org/10.24018/ejeng.2020.5.6.1967.
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This paper presents the results of an experimental study to investigate dynamic properties of polypropylene fiber-reinforced concrete beams with lightweight expanded shale (ES) and tire-derived aggregates (TDA). The mixture design followed past experiences in combining ES and TDA to enhance toughness and energy absorption in flexural behavior. The new mixture also contained 2% fiber by volume to improve such properties further. Experiments included compressive testing on cylindrical specimens as well as flexural testing on rectangular specimens to verify mechanical properties of fiber-reinforced tire-derived lightweight aggregate concrete (FRTDLWAC) subject to static loading. The results of these experiments confirmed reduction of mechanical strength due to addition of TDA and improvements in flexural strength due to fiber reinforcement. The dynamic testing included non-destructive impact loads applied to flexural specimens using a standard Schmidt hammer. A high-speed camera recorded the response of the system at 200 frames per second to allow detailed observations and measurements. Interpretation of energy-based dynamic results revealed that TDA enhances energy absorption through damping in flexural behavior. Results also indicated that fiber reinforcement reduces the amount of absorbed dynamic energy, even though; it enhances the absorbed strain energy due to crack bridging effect.
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Tehrani, Fariborz M., Nazmieh A. Masswadi, Nathan M. Miller, and Arezoo Sadrinezhad. "An Experimental Investigation of Dynamic Properties of Fiber-Reinforced Tire-Derived Lightweight-Aggregate Concrete." European Journal of Engineering Research and Science 5, no. 6 (June 15, 2020): 702–7. http://dx.doi.org/10.24018/ejers.2020.5.6.1967.
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This paper presents the results of an experimental study to investigate dynamic properties of polypropylene fiber-reinforced concrete beams with lightweight expanded shale (ES) and tire-derived aggregates (TDA). The mixture design followed past experiences in combining ES and TDA to enhance toughness and energy absorption in flexural behavior. The new mixture also contained 2% fiber by volume to improve such properties further. Experiments included compressive testing on cylindrical specimens as well as flexural testing on rectangular specimens to verify mechanical properties of fiber-reinforced tire-derived lightweight aggregate concrete (FRTDLWAC) subject to static loading. The results of these experiments confirmed reduction of mechanical strength due to addition of TDA and improvements in flexural strength due to fiber reinforcement. The dynamic testing included non-destructive impact loads applied to flexural specimens using a standard Schmidt hammer. A high-speed camera recorded the response of the system at 200 frames per second to allow detailed observations and measurements. Interpretation of energy-based dynamic results revealed that TDA enhances energy absorption through damping in flexural behavior. Results also indicated that fiber reinforcement reduces the amount of absorbed dynamic energy, even though; it enhances the absorbed strain energy due to crack bridging effect.
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Lou, Qi, Si Rong Yu, Wei Du, and Hong Chao Chu. "Analysis of Abnormal Fracture Occurring during Full Scale Tension Increasing to Failure Test of High Strength Low Alloy Steel Casing." Materials Science Forum 788 (April 2014): 390–95. http://dx.doi.org/10.4028/www.scientific.net/msf.788.390.
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The full scale evaluation test of a set of API Q125 high strength low alloy steel casing specimens was conducted. With the tension increasing to failure, the abnormal fracture occurred on each specimen. A series of testing and analysis including fracture observation, chemical composition analysis, mechanical properties testing, metallographic analysis and SEM analysis were made for the specimen with abnormal spiral fracture. The geometry measurement, visual examination, mechanical properties testing and metallographic analysis were conducted for a new specimen. The mechanical properties of the two specimens are in compliance with the specified material specification. The new specimen has lower external diameter ovality and higher wall thickness eccentricity. The smaller wall thickness is distributed in a spiral shape, similar with the abnormal fracture. The fracture originated in the middle of casing wall, and the fracture position had obvious necking. According to fractography and fracture mechanics analysis, the abnormal spiral fracture was attributed to the metallurgical and geometry imperfection grown out of tubing processing process.
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LIM, SHEAU HOOI, KAIYANG ZENG, and CHAOBIN HE. "PREPARATION, MORPHOLOGY AND MECHANICAL PROPERTIES OF EPOXY NANOCOMPOSITES WITH ALUMINA FILLERS." International Journal of Modern Physics B 24, no. 01n02 (January 20, 2010): 136–47. http://dx.doi.org/10.1142/s021797921006406x.
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This paper presents recent studies on the processing and characterization of epoxy-alumina nanocomposites. Nano-sized alumina particles are incorporated into epoxy resin via solvent-assisted method, so that the particles are dispersed homogeneously in the epoxy matrix. The morphologies, mechanical and thermomechanical properties of the resulting nanocomposites are studied using transmission electron microscope (TEM), conventional tensile testing and thermomechanical testing methods. TEM results show that the alumina nano-particles with a higher specific surface area tend to agglomerate. Furthermore platelet shape particles shows a better dispersion homogeneity as well as better improvement in the mechanical properties of the composites compared to the rod shape particles.
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Liu, Xu, and Rongsheng Lu. "Testing System for the Mechanical Properties of Small-Scale Specimens Based on 3D Microscopic Digital Image Correlation." Sensors 20, no. 12 (June 22, 2020): 3530. http://dx.doi.org/10.3390/s20123530.
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The testing of the mechanical properties of materials on a small scale is difficult because of the small specimen size and the difficulty of measuring the full-field strain. To tackle this problem, a testing system for investigating the mechanical properties of small-scale specimens based on the three-dimensional (3D) microscopic digital image correlation (DIC) combined with a micro tensile machine is proposed. Firstly, the testing system is described in detail, including the design of the micro tensile machine and the 3D microscopic DIC method. Then, the effects of different shape functions on the matching accuracy obtained by the inverse compositional Gauss–Newton (IC-GN) algorithm are investigated and the numerical experiment results verify that the error due to under matched shape functions is far larger than that of overmatched shape functions. The reprojection error is shown to be smaller than before when employing the modified iteratively weighted radial alignment constraint method. Both displacement and uniaxial measurements were performed to demonstrate the 3D microscopic DIC method and the testing system built. The experimental results confirm that the testing system built can accurately measure the full-field strain and mechanical properties of small-scale specimens.
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Wu, Zhonghu, Shuang Wang, Jun Chen, Huailei Song, Wentao Wang, Ruyue Wang, and Hao Liu. "Fracture Propagation Modes of Lower Cambrian Shale Filled with Different Quartz Contents under Seepage-Stress Coupling." Geofluids 2022 (July 25, 2022): 1–18. http://dx.doi.org/10.1155/2022/1051284.
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The content and spatial distribution of brittle minerals, such as quartz, are important factors in determining the fracture initiation mechanism induced by hydraulic fracturing in shale reservoirs. To further research the impact of quartz content in shales of the Lower Cambrian Niutitang Formation in northern Guizhou on the fracture expansion of its reservoir, 7 groups of randomly filling shale models with different quartz contents were established using rock failure process analysis (RFPA2D-flow) code for numerical test studies under seepage-stress coupling, and 5 samples were also subjected to uniaxial compression tests using the INSTRON 1346 electrohydraulic servo-controlled material testing machine (200T). The results show that the average growth rate of the compressive strength and the fracture proportion for a quartz content of 50% to 65% are 4.22 and 1.15 times higher than those for 35% to 50%, respectively. Fractures sprout, expand, and breakdown in the shale matrix or at the junctions of the shale matrix and quartz grains. The mechanical properties and pattern of the fracture extension of the shale in the physical tests are similar to those in the numerical tests, indicating the reliability of the numerical simulations. The fractal dimension curves at different stress levels are divided into three stages: flattening, increasing, and surging, and the fractal dimension value for a quartz content of 50%~65% at a 100% stress level is 1.02 times higher than that for 35%~50%. The high degree of natural fracture development in high quartz content formations in shale gas reservoirs is of some reference value for logging data. The research results provide a reference value for the content and spatial distribution of brittle minerals for the initiation mechanism and fracture propagation of hydraulic fracturing in shale reservoirs.
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Meinecke, Eberhard A., and Mansour I. Taftaf. "Effect of Carbon Black on the Mechanical Properties of Elastomers." Rubber Chemistry and Technology 61, no. 3 (July 1, 1988): 534–47. http://dx.doi.org/10.5254/1.3536199.
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Abstract The strain-amplification concept developed by Guth and Gold can predict the effect of carbon black loading on the mechanical properties of elastomers, provided that the experimental conditions and the samples correspond to the assumptions made in the derivation of the Guth-Gold equation, namely: a) Any artifacts arising from dynamic testing in tension have to be considered and eliminated by the proper analysis. b) Samples have to be prestretched prior to testing to break up particle agglomerations and to eliminate any possible entanglement slippage. c) Spherical particles have to be used or Medalia's occluded volume concept has to be applied for fillers with high structure. d) Hysteresis properties are dependent upon the square of the strain-amplification factor. e) Viscoelastic effects on the shape and level of stress-strain curves have to be eliminated.
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Wang, Shuang, Zhonghu Wu, Jun Chen, Hao Liu, Ruyue Wang, and Jingshou Liu. "Study of the Effect of Mineral Components on the Permeability Impairment Rate and Stress Sensitivity Factor of Shale." Geofluids 2022 (February 21, 2022): 1–15. http://dx.doi.org/10.1155/2022/4407252.
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The mineral components play an indispensable role in shale reservoirs, and the study of their content and character are significant for the permeability impairment rate and stress sensitivity of shale reservoirs. In this study, the shale cores from the FC1 well of the Lower Cambrian Niutitang Formation in northern Guizhou were used to analyze the mineralogical composition of five samples using X-ray diffractometry and for measurement of permeability and porosity of samples by means of the FYKS-2 high-temperature overburden porosimeter with N2, and the samples were also subjected to uniaxial compression tests using the INSTRON 1346 electrohydraulic servo-controlled material testing machine (200T), thereby analyzing the effect of mineral components on the permeability impairment rate and stress sensitivity coefficient of shale. Results indicate that the permeability and porosity are negatively correlated with effective stress and clay mineral content, and positively correlated with detrital mineral content, whereas, the change of mineral composition is not obvious for porosity. Simultaneously, the permeability impairment rate and stress sensitivity factor decrease with growing quartz content and modulus of elasticity, and increase with rising clay mineral content. Additionally, the greater the brittle minerals content of shale, the more likely it is to undergo brittle damage and more crack extension during compression with predominantly elastic deformation, resulting in a lower stress sensitivity factor. Conversely, the higher is the stress sensitivity factor. The research results further deepen the understanding of mineral components on the permeability and mechanical properties of shale reservoirs.
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Rotta, G., T. Seramak, and K. Zasińska. "Estimation of Young’s Modulus of the Porous Titanium Alloy with the Use of Fem Package." Advances in Materials Science 15, no. 4 (December 1, 2015): 29–37. http://dx.doi.org/10.1515/adms-2015-0020.
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Abstract Porous structures made of metal or biopolymers with a structure similar in shape and mechanical properties to human bone can easily be produced by stereolithographic techniques, e.g. selective laser melting (SLM). Numerical methods, like Finite Element Method (FEM) have great potential in testing new scaffold designs, according to their mechanical properties before manufacturing, i.e. strength or stiffness. An example of such designs are scaffolds used in biomedical applications, like in orthopedics’ and mechanical properties of these structures should meet specific requirements. This paper shows how mechanical properties of proposed scaffolds can be estimated with regard to total porosity and pore shape.
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Surakamhang, Panta, and Chontira Sangsubun. "Structure and Mechanical Properties of Water Buffalo Horns." Applied Mechanics and Materials 804 (October 2015): 247–50. http://dx.doi.org/10.4028/www.scientific.net/amm.804.247.
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Many studies have been reported in the field of biological materials. For the most part, this interest has focused on teeth, bones, hooves and horns, elucidating the relationship between structure and mechanical properties. Due to their novel outstanding structures and mechanical properties, this knowledge is helpful for the use and design of the superior bio-inspired synthetic materials. Similarly, this research aims to investigate the microstructure and mechanical properties of the water buffalo horn in 1-5 years old in Phatthalung province in southern Thailand. The tensile properties and the Young’s modulus were systematically measured by a universal testing machine. The hardness was determined by micro vickers hardness testing machines. The results showed that the average of Young’s modulus, the tensile strength at break and the vickers hardness of a 2-year-old water buffalo horn were about 6.1 GPa, 92.6 MPa and 180 MPa, respectively, which were higher than that at 1, 3, 4 and 5 years old. The elongation at break of a 1 year old water buffalo horn has a maximum value of 61%. The microstructure and chemical composition were investigated using scanning electron microscopy (SEM) and energy dispersive X-ray spectrometer (EDX), respectively. The results of SEM showed that the fracture surface of the water buffalo horn has a rippled shape in each layer. The EDX analysis showed that the water buffalo horn consists of carbon, nitrogen, sulfur and oxygen.
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Nes, O. M., Per Horsrud, E. F. Sonstebo, R. M. Holt, A. M. Ese, Dag Okland, and Halvor Kjorholt. "Rig Site and Laboratory Use of CWT Acoustic Velocity Measurements on Cuttings." SPE Reservoir Evaluation & Engineering 1, no. 04 (August 1, 1998): 282–87. http://dx.doi.org/10.2118/50982-pa.
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This paper (SPE 50982) was revised for publication from paper SPE 36854, first presented at the 1996 SPE European Petroleum Conference held in Milan, Italy, 22-24 October. Original manuscript received for review 8 November 1996. Revised manuscript received 21 May 1998. Paper peer approved 1 June 1998. Summary A continuous wave technique (CWT) for measurement of acoustic phase velocities on cuttings is presented. The equipment is particularly well suited for testing of small samples like cuttings, and measurements, even on sub-mm-thick shale cuttings, have been performed. This yields potential access to a new source of data on the drilled formation that can also be attained in quasireal time at the rig site. The prototype equipment developed is portable, fast, and easy to use. Tests have been performed both at the rig site and in the laboratory. Potential applications include estimation of mechanical properties of shales, effects of various fluids and drilling muds, estimation of seismic parameters, and estimation of pore pressure. P. 282
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Maletta, Carmine, Luigino Filice, and Franco Furgiuele. "NiTi Belleville washers: Design, manufacturing and testing." Journal of Intelligent Material Systems and Structures 24, no. 6 (May 6, 2012): 695–703. http://dx.doi.org/10.1177/1045389x12444490.
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The thermomechanical properties of nickel–titanium-based Belleville washers have been analyzed in this investigation, together with their unusual mechanical and functional features, which can be attributed to the reversible phase transformation mechanisms of nickel–titanium alloys. In particular, numerical simulations have been carried out for a preliminary design of the Belleville washer, using a commercial finite element software and a special constitutive model for shape memory alloys. Subsequently, Belleville washers have been manufactured from a commercial pseudoelastic nickel–titanium alloy, by disk cutting and a successive shape setting by a thermomechanical treatment. Finally, the thermomechanical response of the washers, in terms of isothermal force–deflection curve and thermal cycles between phase transition temperatures, has been experimentally analyzed. The results highlighted a marked effect of the temperature on the characteristic curve, as well as good recovery capabilities under both mechanical and thermal cycles. In addition, nickel–titanium Belleville washers exhibit a marked hysteretic behavior, as a consequence of the hysteresis in the stress–strain response of the alloy. Thanks to these features, nickel–titanium Belleville washers can be used as smart elastic elements, that is, with tunable stiffness and damping properties, as well as solid-state actuators, due to their recovery capabilities.
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Özdemir, Özer, Selim Gürgen, and Melih Cemal Kuşhan. "Ultrasonic Inspection for Microstructural and Mechanical Properties of Ductile Cast Iron." Advanced Engineering Forum 39 (February 2021): 9–19. http://dx.doi.org/10.4028/www.scientific.net/aef.39.9.
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Ultrasonic inspection is a well-known method in non-destructive testing. Based on the changes in the ultrasonic sound speed, tested materials are evaluated in terms of internal defects. In addition to flaw detection, ultrasonic testing is used in the material characterization of ductile cast iron. Graphite shape detection has been widely investigated by ultrasonic inspection in literature. However, most of the measurements has been conducted at single frequencies. In this work, three different nodulizer included casting operations were carried out to produce ductile cast irons having various graphite morphologies. A wide frequency range of 1.25-10 MHz was selected in the ultrasonic inspection. In addition to graphite morphology analyses, the relationship between ultrasonic sound speed and mechanical properties was studied. In the mechanical analyses, hardness and tensile testing properties were investigated for the specimens. From the results, ultrasonic sound speed exhibits a considerable dependency to the graphite morphology. In addition to a good graphite detection capability, ultrasonic inspection exhibits promising results for predicting the mechanical properties such as hardness, elastic modulus, yield strength and tensile strength. It is also found that there is a slight increase in the ultrasonic sound speed by increasing the frequency, although sound speed is independent from this parameter.
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Zhu, Huai Liang, Li Feng Yu, Jing Ni, Xue Wang, and Ren An Luo. "Testing and Evaluation of Mechanical Properties for Anisotropic Engineering Materials with Varied Loads." Key Engineering Materials 544 (March 2013): 471–75. http://dx.doi.org/10.4028/www.scientific.net/kem.544.471.
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This paper is aimed at investigating the influence of load-bearing style on the mechanical behavior of anisotropic engineering materials. The study on elastic constants and failure forms of materials will be presented under different loading condition. Firstly, the mechanical properties of unidirectional holey laminated materials are discussed based on the uniaxial tensile tests. The equivalent elastic modulus, Poisson’s ratio and shear modulus are obtained, and the pattern and mechanism of failure are analyzed. Then, the biaxial tensile tests are carried out for PVC orthotropic membrane materials with different stress ratio between the warp and weft direction. A comparison of limit strengths under biaxial loadings is given with that in uniaxial loading case. Finally, the dynamical behaviors of shape memory alloy (SMA), iron wire, and rubber composite as well as compound rubber are studied respectively by impact-tension tests. The failure forms, energy dissipation ratio and impact-tension toughness of materials are analyzed. It is shown that the mechanical properties and failure pattern of anisotropic materials have much to do with the load-bearing styles. It agrees well with actual properties of anisotropic material used in engineering structures.
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Dam, Aimimi Mat, and Zakiah Kamdi. "Study on Mechanical Properties of Polyester with Addition of Recycle Gift or Members Card." Journal of Physics: Conference Series 2080, no. 1 (November 1, 2021): 012006. http://dx.doi.org/10.1088/1742-6596/2080/1/012006.
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Abstract Increasing usage of gift cards will end up increasing the waste. Instead of throwing in the dustbin, re-cycling the cards may help in increasing the product usage and contribute to the environment sustainability. In this study, the re-cycle gift cards were combined with polyester to produce polymer blend. The composition of re-cycle gift cards was 2, 4 and 6 wt%. The gift card was crush and mix with the polyester and hardener followed by casting to get the suitable shape based on the testing. Three testing was undergone to evaluate the polymer blend properties which are tensile test, Charpy’s impact test and Durometer hardness test. Similar trend was shown for all mechanical testing which showing an increase of performance from 2 to 4 wt% addition of recycle cards but reduce when achieved 6 wt%.
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Chen, B. "Material Characterization of Tire Cords and the Effects of Cord Thermal-Mechanical Properties on Tires." Tire Science and Technology 32, no. 1 (January 1, 2004): 2–22. http://dx.doi.org/10.2346/1.2186771.
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Abstract Thermal-mechanical properties of tire cords have a great influence on tire dimension, shape, handling, and other performance related issues. This study focuses on characterizing the material properties for polymeric cords and quantifying their effects on pneumatic tires using finite element analysis (FEA). Various tire cord materials, including nylon and polyester, were characterized by obtaining a series of thermal-mechanical properties in the laboratory using tensile testing, thermal shrinkage measurement and creep testing. Prior to obtaining these laboratory measurements, cords in this study were subjected to thermal-mechanical pre-treatments to simulate the effects of curing and tire operating conditions. The properties derived from these measurements were used as input properties for a finite element analysis of a physical tire. Predictions of tire dimensions and shape, loaded footprint and pressure and cord loads were obtained from the FEA model and compared to measured values of the experimental tire. Good agreement was observed between the measured values and those predicted from the finite element analysis; therefore, future FEA studies of pneumatic tires should utilize the techniques developed in this study to characterize tire cord materials.
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Feng, Zhao Wei, Jiang Bo Wang, Xu Jun Mi, Wei Dong Miao, Zhi Shan Yuan, and Jin Zhou. "Effects of Ni/Ti Ratio and Heat-Treatment on Transformation Temperature, Mechanical Properties and Shape Recovery Strain of Ni-Ti-Nb Alloy." Advanced Materials Research 535-537 (June 2012): 919–23. http://dx.doi.org/10.4028/www.scientific.net/amr.535-537.919.
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Ni-Ti-Nb wide hysteresis shape memory alloys of three Ni/Ti ratio components were manufactured by vacuum induction melting. The transformation temperature, mechanical properties and recovery strain were studied by using differential scanning calorimeter and material testing machine. It shows that with Ni/Ti ratio increase, the transformation temperature and mechanical properties decrease. Shape recovery strain is higher when Ni/Ti ratio is 1.068, with recovery strain range from 6.8 to 7.5. The faster the cooling rate after annealing, the higher is the transformation temperature, and the lower are the mechanical properties and recovery strain.
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Gligor, Ionuţ, Viorel Cândea, George Arghir, and Catalin Popa. "Elaboration of Titanium-Nickel Alloy with Special Properties through Mechanical Milling." Materials Science Forum 672 (January 2011): 121–24. http://dx.doi.org/10.4028/www.scientific.net/msf.672.121.
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Shape memory Titanium-Nickel alloys, also known as Nitinol, are amongst the most utilized materials with special properties in the medical field. Together with the properties of shape memory and superelasticity, these alloys have a very good biocompatibility. In this study, the equiatomic Ti-Ni alloy was obtained in the form of alloyed powder, starting from elemental high purity powders, through mechanical alloying. Specimens for testing the mechanical characteristics of the material, as well as smaller samples for biocompatibility tests were manufactured. The latter ones were prepared for implantation on live tissue, on Wistar rats and Guinea pigs. The structure of samples was studied by microscopy and X-Ray diffraction analysis. All the results have demonstrated the presence of the TiNi intermetallic compound as the quantitative dominant phase. After applying an adequate thermo-mechanical treatment, the tested samples displayed measurable shape memory effect and superelasticity. The in vivo biocompatibility tests, done according to international standards, demonstrated the material’s bio-inertness in relation with living tissue. The obtained results have shown the possibility to elaborate Ti-Ni biocompatible alloys by mechanical milling and sintering.
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Matyunin, V. M., A. P. Sliva, A. Marchenkov Yu, D. A. Zhgut, R. V. Rodyakina, M. A. Karimbekov, P. V. Volkov, and A. N. Demidov. "Non-destructive testing of physical and mechanical properties of local zones in welded joints." Journal of Physics: Conference Series 2275, no. 1 (June 1, 2022): 012002. http://dx.doi.org/10.1088/1742-6596/2275/1/012002.
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Abstract The influence of the “saw-tooth” type electron beam sweep on the penetration shape during electron-beam welding of 30KhGSA high-strength steel with different welding modes was investigated. Using the instrumented indentation method, the distribution of Young’s modulus, as well as the characteristics of strength and plasticity in the welded joints cross-sections, was obtained. It has been found that in the weld metal there is a sharp increase in strength characteristics, while the plasticity ones are significantly reduced. The values of the Young’s modulus also varied over the cross-sections. The considerable decrease in this characteristic (up to 20%) was registered in the weld metal in comparison with the parent metal results.
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Li, Xu Chang, Jian Jiao, Jun Yan Yao, and Liang Wang. "Study on the Relationship between Microscopic Structure and Mechanical Properties of HTPB Propellant." Advanced Materials Research 152-153 (October 2010): 1151–55. http://dx.doi.org/10.4028/www.scientific.net/amr.152-153.1151.
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By means of a tensile instrument and SEM, the mechanical property parameters of HTPB propellant test samples with different formulas were tested, and their microscopic fracture cross section patterns were observed. Take advantage of these testing results, the relationship between microscopic structure and mechanical properties of HTPB propellant was studied. The results show that the mechanical properties of a propellant are closely related to its microscpic structure state. The structural integrity of propellant is mainly influenced by the bond effect of the interface between binder and solid particles, solid particle’s shape, size and its distribution, the content of binder matrix, etc. These factors have important effects on the mechanical properties of propellant.
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Zhao, Peng Cheng, Yu Bao Niu, Shuo Qin, and Yang Tao Yu. "Effect of Bucking on the Mechanical Properties of Honeycomb Sandwich Structure." Applied Mechanics and Materials 484-485 (January 2014): 705–7. http://dx.doi.org/10.4028/www.scientific.net/amm.484-485.705.
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Static compression test on the Honeycomb sandwich structure with surface core defect carry out in this paper. The specimen divided into four groups, one had no defect, one had circle defect, the other two groups had rectangular defect in different direction. In the process of loading the strain gauge which located on the specimen surface in each group record the strain transformation of the specimen surface. Through the Static load test on the fatigue testing machine, fracture load of each specimen was record. According to the data, how the size and shape of the defect influence the compression static strength of Honeycomb sandwich was discussed, and inspecting defects direction how to affect the structural static strength by means of theoretical analysis and data fitting, meanwhile the shape of the defects in structure how to effect buckling was discussed too.
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Zhang, Xiao, Su Yuan Yang, and Sheng Nan Yang. "Research on Compression Properties of Ni-Ti Shape Memory Alloys." Applied Mechanics and Materials 782 (August 2015): 119–23. http://dx.doi.org/10.4028/www.scientific.net/amm.782.119.
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Quasi-static and dynamic compressive mechanical properties of Ni-Ti shape memory alloys have been investigated by using electronic universal testing machine and Split-Hopkinson Pressure Bar (SHPB), respectively. The experimental results show that the dynamic yield stress and the fracture stress are higher than those in the static. Martensitic phase transformation is induced by stress before the plastic deformation. The critical stress of SIM and the slope of stress plateau increase with the increase of strain rates.
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Saenz-Castillo, Diego, María I. Martín, Vanessa García-Martínez, Abhiram Ramesh, Mark Battley, and Alfredo Güemes. "A comparison of mechanical properties and X-ray tomography analysis of different out-of-autoclave manufactured thermoplastic composites." Journal of Reinforced Plastics and Composites 39, no. 19-20 (May 7, 2020): 703–20. http://dx.doi.org/10.1177/0731684420924081.
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Three different out-of-autoclave manufacturing processes of CF/poly-ether-ether-ketone thermoplastic composites were characterized, including innovative laser-assisted automated fibre placement with in situ consolidation. Characterization techniques included differential scanning calorimetry, ultrasonic non-destructive testing and matrix digestion, in addition to 3D X-ray microcomputed tomography to investigate the void distribution, size and shape. The results revealed that in situ consolidation process can lead to the accumulation of large voids between the upper layers. Interlaminar shear, in-plane shear, tensile and flexure testing were used for mechanical evaluation. A reduction in the mechanical properties was observed for in situ consolidation laminates when compared to the other out-of-autoclave methods. The drop in mechanical properties of in situ consolidation laminates was mainly attributed to the differences found in void distribution and size. Optimization of processing parameters along with higher quality prepreg raw material could be of assistance for the improvement of mechanical properties of in situ consolidation structures.
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Yang, Sheng Nan, and Su Yuan Yang. "Research on Mechanical Properties of TiNi Shape Memory Alloy Wires Reinforced Al Matrix Composite Material." Advanced Materials Research 1120-1121 (July 2015): 502–6. http://dx.doi.org/10.4028/www.scientific.net/amr.1120-1121.502.
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TiNi/Al shape memory alloy (SMA) composite was fabricated by a vacuum hot-pressing method to investigate the phase , microstructure and mechanical properties. Phase analysis was conducted by XRD . Interface bonding between TiNi wire and Al matrix was observed by using SEM and EDS. Quasi-static and dynamic compressive mechanical properties of the composite were investigated by using electronic universal testing machine (INSTRON5985) and Split-Hopkinson Pressure Bar (SHPB),respectively. The experiment results show that new phases Ni4Ti3 and Ti2Ni precipitined from TiNi wire. Interfacial reactions occurred at the bonding between matrix and TiNi wire, creating a diffusion layer about 2μm thick. Both quasi-static and dynamic compressive mechanical properties are anisotropic , and the degree of the anisotropy increased with the increase of TiNi volume fraction.
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Cen, Hao, Shan Li, Ming Liang Du, and Ya Qin Fu. "Fabrication and Properties of Shape Memory Polyurethane Surface Modified Vapor Grown Carbon Nanofiber Composites." Advanced Materials Research 239-242 (May 2011): 855–59. http://dx.doi.org/10.4028/www.scientific.net/amr.239-242.855.
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Shape memory polyurethane (SMPU)/Vapor grown carbon nanofibers (VGCNF) composites with different surface functionalized method were prepared via sol-gel process. The structure and properties of the composites were investigated by scanning electron microscopy (SEM), universal testing machine, and dynamic mechanical analysis (DMA). The results show that the dispersion of VGCNF with surface modification in matrix is better than that of pristine. The mechanical properties of the composites with VGCNF modified by concentrated nitric acid deteriorated substantially. However, both the tensile strength and elongation at break of the composites combined surface modification of silane coupling agent and sol-gel method increased obviously. The substantially improved mechanical properties are mainly attributed to the cross-link between coupling agent and the network structure of SiO2produced during the sol-gel process. The DMA analysis suggests that the surface treatment of the VGCNF exhibit obviously effect on the dynamic mechanical properties of the composites.
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Lin, Yun, Feng Gao, Keping Zhou, Rugao Gao, and Hongquan Guo. "Mechanical Properties and Statistical Damage Constitutive Model of Rock under a Coupled Chemical-Mechanical Condition." Geofluids 2019 (May 14, 2019): 1–17. http://dx.doi.org/10.1155/2019/7349584.
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Chemical corrosion has a significant impact on the damage evolution behavior of rock. To investigate the mechanical damage evolution process of rock under a coupled chemical-mechanical (CM) condition, an improved statistical damage constitutive model was established using the Drucker-Prager (D-P) strength criterion and two-parameter Weibull distribution. The damage variable correction coefficient and chemical damage variable which was determined by porosity were also considered in the model. Moreover, a series of conventional triaxial compressive tests were carried out to investigate the mechanical properties of sandstone specimens under the effect of chemical corrosion. The relationship between rock mechanics properties and confining pressure was also explored to determine Weibull distribution parameters, including the shape parameter m and scale parameter F0. Then, the reliability of the damage constitutive model was verified based on experimental data. The results of this study are as follows: (i) the porosity of sandstone increased and the mechanical properties degraded after chemical corrosion; (ii) the relationships among the compressive strength, the peak axial strain, and confining pressures were linear, while the relationships among the elastic modulus, the residual strength, and confining pressures were exponential functions; and (iii) the improved statistical damage constitutive model was in good agreement with the testing curves with R2>0.98. It is hoped that the study can provide an alternative method to analyze the damage constitutive behavior of rock under a coupled chemical-mechanical condition.
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Gao, Min, Zhengzhao Liang, Shanpo Jia, and Jiuqun Zou. "Tensile Properties and Tensile Failure Criteria of Layered Rocks." Applied Sciences 12, no. 12 (June 15, 2022): 6063. http://dx.doi.org/10.3390/app12126063.
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Rocks are less resistant to tension than to compression or shear. Tension cracks commonly initiate compression or shear failure. The mechanical behavior of layered rocks under compression has been studied extensively, whereas the tensile behavior still remains uncertain. In this paper, we study the effect of layer orientation on the strength and failure patterns of layered rocks under direct and indirect tension through experimental and numerical testing (RFPA2D: numerical software of Rock Failure Process Analysis). The results suggest that the dip angle of the bedding planes significantly affects the tensile strength, failure patterns, and progressive deformation of layered rocks. The failure modes of the layered specimens indicate that the tensile strength obtained by the Brazilian disc test is not as accurate as that obtained by the direct tension test. Therefore, the modified Single Plane of Weakness (MSPW) failure criterion is proposed to predict the tensile strength of the layered rocks based on the failure modes of direct tension. The analytical predictions of the MSPW failure criterion agrees closely with the experimental and numerical results. In rock engineering, the MSPW failure criterion can conveniently predict the tensile strength and reflect the failure modes of layered rocks (such as shale, slate, and layered sandstone) with satisfactory accuracy.
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Daghia, Federica, Gabriella Faiella, Vincenza Antonucci, and Michele Giordano. "Thermomechanical Modelling and Experimental Testing of a Shape Memory Alloy Hybrid Composite Plate." Advances in Science and Technology 59 (September 2008): 41–46. http://dx.doi.org/10.4028/www.scientific.net/ast.59.41.
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Shape memory alloys (SMA) exhibit functional properties associated with the shape memory effect, responsible of the SMA shape recovery after a cycle of deforming-heating and of a simultaneous generation of mechanical work. Composite systems incorporating SMA wires have the ability to actively change shape and other structural characteristics. The functional properties of such adaptive composites are related to the martensitic transformation in the SMA elements and to the constraining behaviour that the composite matrix has on the SMA wires. In this work the behaviour of a shape memory alloy hybrid composite (SMAHC) is numerically and experimentally investigated. A plate was fabricated using prestrained SMA wires embedded in an epoxy resin pre preg glass fibres composite system. Upon calorimetric and mechanical material characterization, a finite element model was used in order to predict the structural behaviour of the SMAHC. In the experimental tests, the plate was clamped at one side and actuated via electrical heating. Temperature and displacement data were collected and compared with the prediction of the finite element model. The results show that the model is able to capture the shape change in the actuation region, although a thorough description of the SMAHC behaviour requires further modelling work, including the simulation of the SMA loading history during composite manufacturing.
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Junaedi, Harri, Muneer Baig, Abdulsattar Dawood, Essam Albahkali, and Abdulhakim Almajid. "Effect of the Matrix Melt Flow Index and Fillers on Mechanical Properties of Polypropylene-Based Composites." Materials 15, no. 21 (October 28, 2022): 7568. http://dx.doi.org/10.3390/ma15217568.
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In this work, mechanical properties of reinforced polypropylene composites were studied. PP in particulates shape with two different melt flow indexes (MFI) was used, i.e., 3 and 23 g/10 min, namely PP3 and PP23, respectively. Three different materials, namely TiO2 nanoparticle (nTiO2, spherical, 0D), micro-size short carbon fiber (SCF, fiber, 1D), and graphite nanoplatelet (GNP, sheet, 2D), were used as reinforcements/fillers. PP and fillers (in the desired composition) were first pre-mixed by a mechanical mixer. The mixture was then fed to a co-rotating twin-screw extruder for melt-compounding, followed by injection molding to fabricate testing samples. The microstructure and fracture surface of the composites were observed by a scanning electron microscope (SEM). Additionally, tensile, flexural, impact, and hardness tests were conducted to evaluate their mechanical properties. The SEM images stipulate that PP23 had better adhesion and dispersion with the fillers. The results from the SEM images support the mechanical testing results. PP23 composites exhibited more significant improvement in mechanical properties in comparison to PP3. At 5 wt. % filler loading, PP/GNP composite exhibited a greater improvement in mechanical properties compared with two other composites, which are PP/SCF and PP/nTiO2 composites for both PPs.
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Hassan, Md Sahid, Luis A. Chavez, Chien-Chun Chou, Samuel E. Hall, Tzu-Liang Tseng, and Yirong Lin. "Mechanical response of shape-recovering metamaterial structures fabricated by additive manufacturing." Materials Research Express 8, no. 11 (November 1, 2021): 115801. http://dx.doi.org/10.1088/2053-1591/ac343f.
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Abstract Three different metamaterial structures were fabricated using stereolithography 3D printing and a shape recovering material. Mechanical properties and recovery efficiency were assessed after compression testing. All three structures exhibited similar initial specific compressive moduli, while the highest specific toughness was observed for the stretch-dominated structure. The three metamaterial structures were re-tested after shape recovery. Significant strengthening was observed for all structures, with the bend-stretch-dominated structure strengthening to the highest degree. This strengthening phenomenon was characterized as strain hardening. It was found that the strengthening is highly geometry dependent. The geometry with stretch-dominated behavior exhibited the highest mechanical properties after a second test was performed. Improvements in specific toughness of up to 67% were observed after the second compressive test.
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Haidzir, H., Dayang Laila Majid, A. S. M. Rafie, and M. Y. Harmin. "Modal Properties of Hybrid Carbon/Kevlar Composite Thin Plate and Hollow Wing Model." Applied Mechanics and Materials 446-447 (November 2013): 597–601. http://dx.doi.org/10.4028/www.scientific.net/amm.446-447.597.
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In any flutter prediction analysis, modal testing is necessary because flutter, a resonant like vibration occurs at a flutter frequency and adopts a mode shape akin to its structural natural modes. Modal testing can be performed computationally with knowledge of the mechanical properties of the structure. In the present work, computational modal analysis is first performed on a cantilevered hybrid composite thin plate and validated experimentally. Then, the computational procedure is demonstrated on a composite hollow wing model of same material. The concept of hollow wing is explored due to the superior mechanical properties of carbon/kevlar composite plate. It is observed that the natural frequencies of the hollow wing model are higher than thin plate due to stiffer configuration. A breathing mode was also observed at mode 4 for the hollow wing.
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Šmídová, Natália, Hamed Peidayesh, Anton Baran, Oľga Fričová, Mária Kovaľaková, Ružena Králiková, and Ivan Chodák. "Influence of Air Humidity Level on the Structure and Mechanical Properties of Thermoplastic Starch-Montmorillonite Nanocomposite during Storage." Materials 16, no. 3 (January 17, 2023): 900. http://dx.doi.org/10.3390/ma16030900.
Full textAbstract:
Thermoplastic starch (TPS) consisting of corn starch and glycerol as a plasticizer, and TPS-montmorillonite (MMT) nanocomposite were stored at room temperature in the air with relative humidities (RH) of 11, 55 and 85% for seven weeks. Mechanical testing and dynamic mechanical thermal analysis (DMTA) were performed to detect changes in their mechanical properties. Solid-state NMR spectroscopy monitoring the changes in molecular mobility in the samples provided an insight into relations between mechanical properties and local structure. The results of mechanical testing indicated that the addition of MMT results in the increase in the tensile strength and Young’s modulus while elongation at break decreased, indicating the reinforcing effect of MMT. DMTA experiments revealed a decrease in glass transition temperature of starch-rich phase below room temperature for samples stored at higher RH (55 and 85%). This indicates that absorbed water molecules had additional plasticizing effect on starch resulting in higher mobility of starch chain segments. Recrystallization in these samples was deduced from the shape of cross-polarization magic-angle spinning 13C NMR spectra. The shape of broad-line 1H NMR spectra reflected changes in molecular mobility in the studied samples during seven weeks of storage and revealed that a high amount of water molecules impacts the starch intermolecular hydrogen bond density.