Journal articles: 'Monotonic torsional loading'

1

Georgiannou, V. N., and A. Tsomokos. "Comparison of two fine sands under torsional loading." Canadian Geotechnical Journal 45, no. 12 (December 2008): 1659–72. http://dx.doi.org/10.1139/t08-083.

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In this paper the behaviour of two “standard research sands”, widely used for experimental purposes, is compared in a torsional hollow cylinder apparatus under monotonic and cyclic loading conditions. Both sands are fine and uniform with D50 = 0.22 and 0.29 mm, respectively. However, their response to undrained monotonic loading at similar void ratios is dramatically different, with the finer sand showing strength reduction after peak and the coarser sand showing continuous increase in strength with torsional shear. The difference in response is mainly attributed to grain angularity and to a lesser degree to their grading. The results of drained torsional hollow cylinder tests show initial contraction followed by dilation. The stress ratio at phase transformation is uniquely defined by both drained and undrained tests for each sand. Cyclic loading instability is manifested by a sudden increase in shear strain and excess pore-water pressure leading to initial liquefaction. The instability initiates across the instability line for the sand showing strength reduction and across the phase transformation line for the sand showing continuous increase in strength with shearing. Both lines are defined under monotonic loading conditions. The liquefaction, stiffness, and damping characteristics of the sands are given in this paper.

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Yasuda, Nario, and Norihisa Matsumoto. "Comparisons of deformation characteristics of rockfill materials using monotonic and cyclic loading laboratory tests and in situ tests." Canadian Geotechnical Journal 31, no. 2 (April 1, 1994): 162–74. http://dx.doi.org/10.1139/t94-022.

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The deformation characteristics of rockfill materials at very small strains were investigated by comparing the results of monotonic and cyclic loading laboratory tests with geophysical P- and S-wave logging data from the field. Using a precision linear variable differential transformer for displacement, the elastic moduli of rockfill materials at very small strains were measured in monotonic and cyclic loading triaxial tests. The laboratory test results agreed well with the field results. The shear moduli of rockfill materials from both a monotonic loading torsional simple shear test and a cyclic loading torsional simple shear test also showed good correspondence. Furthermore, the shear modulus predicted from the in situ shear wave tests in rockfill dams corresponded reasonably well with the modulus in the large-scale triaxial tests in the laboratory. Key words : deformation characteristics, embankment dams, rockfill materials, laboratory test, in situ test.

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Georgiannou, V. N., A. Tsomokos, and K. Stavrou. "Monotonic and cyclic behaviour of sand under torsional loading." Géotechnique 58, no. 2 (March 2008): 113–24. http://dx.doi.org/10.1680/geot.2008.58.2.113.

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Kowalewski, Zbigniew L., and Tadeusz Szymczak. "An Influence of Step Cyclic Loading due to Torsion on Tensile Curve Variation." Key Engineering Materials 535-536 (January 2013): 181–84. http://dx.doi.org/10.4028/www.scientific.net/kem.535-536.181.

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The paper presents experimental results of tests carried out at room temperature on power engineering steel: 10H2M (11CrMo9-10) using thin-walled tubular specimens under biaxial stress state. The loading programme comprised different types of deformation, i.e. monotonic tension and cyclic torsion in the form of symmetric or asymmetric step-increasing strain amplitude. The main task of the paper was focused on investigation of an influence of the cyclic loading parameters on tensile curve variations. The magnitudes of axial strain and cyclic shear strain amplitude were small and did not exceed 1%. An analysis of the results showed a significant reduction of the axial stress (even equal 90% for the torsional amplitude ±0.8%, in both cases of cyclic loading). An influence of torsion frequency on the tensile stress curve was discovered within the range from 0.005Hz to 0.5Hz.

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Kedgley, Angela E., Sarah E. Takaki, Pencilla Lang, and Cynthia E. Dunning. "The Effect of Cross-Sectional Stem Shape on the Torsional Stability of Cemented Implant Components." Journal of Biomechanical Engineering 129, no. 3 (November 14, 2006): 310–14. http://dx.doi.org/10.1115/1.2720907.

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Stability of a cemented implant, once the stem-cement interface has debonded, is reliant upon stem geometry and surface finish. There are relatively few studies addressing the effect of cross-sectional stem shape on cemented implant fixation. The purpose of this investigation was to compare the torsional stability of five different stem cross-sectional shapes—circular, oval, triangular, rectangular with rounded edges, and rectangular with sharp edges—under monotonically increasing and cyclic loading conditions. Seven samples of each stem geometry were tested. Stems were potted in bone cement and loaded to 5 deg of rotation. For monotonic loading, torque was applied at a constant rate of 2.5 deg/min. For cyclic loading, a sine wave torque pattern was applied, with a maximum magnitude that began at 4.5 Nm for 1500 cycles and then increased by 2.25 Nm every 1500 cycles until 5 deg of rotation. The rectangular stem with the sharp edges always provided the greatest resistance to torque, followed by the rectangular with rounded edges, triangular, oval, and circular. These results, including the effects of sharp corners, may differ for modes of loading other than torsion. These experimental results support the findings of earlier finite element models, indicating stem shape has a significant effect on resistance to torsional loading.

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Ramaswamy, V. G., D. C. Stouffer, and J. H. Laflen. "A Unified Constitutive Model for the Inelastic Uniaxial Response of Rene’ 80 at Temperatures Between 538C and 982C." Journal of Engineering Materials and Technology 112, no. 3 (July 1, 1990): 280–86. http://dx.doi.org/10.1115/1.2903324.

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The objective of this research is to develop a constitutive equation for the uniaxial monotonic and cyclic response of Rene’80 between the temperatures of 538C and 982C. The constitutive equation is accompanied by experimental data for the evaluation of the material constants. Extensive verification is achieved through the successful correlation of tensile and creep response and prediction of mechanical cycling experiments including mean stress shifts. These results also serve as a starting point for reformulating the model for the prediction of the high temperature multiaxial response of Rene’80 that includes torsion, proportional, and nonproportional uniaxial and torsional loading histories.

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Li, Bingbing, Dunji Yu, and Xu Chen. "Effects of mean strain and tensile pre-strain on torsional fatigue behaviours of duplex stainless steel SAF2205." MATEC Web of Conferences 165 (2018): 15003. http://dx.doi.org/10.1051/matecconf/201816515003.

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Effects of mean strain and tensile pre-strain were investigated on the torsional fatigue behaviours of duplex stainless steel SAF2205. Two equivalent strain amplitudes (0.5%,0.7 %), three strain ratios (-1, - 0.5, -0.25) and 5% tensile pre-strain were chosen. Results indicated that the mean strain had no distinct influences on the torsional fatigue behaviours in terms of cyclic stress reponse and fatigue life while tensile pre-straining made a significant increase in cyclic stress response which was mainly attributed to the cross hardening derived from the loading sequence of monotonic tension preceding to cyclic torsion and led to a reduction in fatigue life. The failure mechanisms were revealed by scanning electron microscope characterized by microcracks initiation at the extrusions in ferrite and phase boundary inhibited further propagation. Additionally, the fractography of all fatigued specimens revealed a quasi-cleavage brittle mode with features of distinct tearing ridges and cleavage facets.

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Kim, J., M. Kazama, and Y. Kwon. "Effects of relative density and accumulated shear strain on post-liquefaction residual deformation." Natural Hazards and Earth System Sciences Discussions 1, no. 2 (April 24, 2013): 1579–617. http://dx.doi.org/10.5194/nhessd-1-1579-2013.

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Abstract. The damage caused by liquefaction, which occurs following an earthquake, is usually because of settlement and lateral spreading. Generally, the evaluation of liquefaction has been centered on settlement, that is, residual volumetric strain. However, in actual soil, residual shear and residual volumetric deformations occur simultaneously after an earthquake. Therefore, the simultaneous evaluation of the two phenomena and the clarification of their relationship are likely to evaluate post-liquefaction soil behaviors accurately. Hence, a quantitative evaluation of post-liquefaction damage will also be possible. In this study, the effects of relative density and accumulated shear strain on post-liquefaction residual deformations were reviewed through a series of undrained K0 control cylindrical torsional tests. In order to identify the relationship between residual shear and residual volumetric strains, this study proposed a new test method that integrates monotonic loading after cyclic loading, and K0 drain after cyclic loading-in other words, the combination of cyclic loading, monotonic loading, and the K0 drain. In addition, a control that maintained the K0 condition across all the processes of consolidation, cyclic loading, monotonic loading, and drainage was used to reproduce the anisotropy of in-situ ground. This K0 control was performed by controlling the axial strain, based on the assumption that under undrained conditions, axial and lateral strains occur simultaneously, and unless axial strain occurs, lateral strain does not occur. The test results confirmed that the restoration behaviors of effective stresses, which occur during monotonic loading and drainage after cyclic loading, respectively, result from mutually different structure restoration characteristics. In addition, in the ranges of 40~60% relative density and 50~100% accumulated shear strain, relative density was found to have greater effects than the number of cycles (accumulated shear strain).

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Jiang, W. "The Elastic-Plastic Response of Thin-Walled Tubes Under Combined Axial and Torsional Loads: Part I—Monotonic Loading." Journal of Pressure Vessel Technology 115, no. 3 (August 1, 1993): 283–90. http://dx.doi.org/10.1115/1.2929529.

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This paper investigates the elastic-plastic response of thin-walled tubes subjected to combined axial and torsional loads. The kinematic hardening model is used and exact closed-form solutions are obtained for linear loading paths. The characteristics of the stress-strain relationships are discussed and the corresponding movements of the yield center are illustrated. The response of the material under nonproportional loading is proved to be path-dependent, and the hardening behavior is shown to be different from that under proportional loading. The investigation then shows that such a difference will finally disappear when the stresses tend to infinity.

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Sabelkin, Volodymyr P., Gregory R. Cobb, Benjamin M. Doane, Ryan A. Kemnitz, and Ryan P. O’Hara. "Torsional behavior of additively manufactured nickel alloy 718 under monotonic loading and low cycle fatigue." Materials Today Communications 24 (September 2020): 101256. http://dx.doi.org/10.1016/j.mtcomm.2020.101256.

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11

Jaafer, Abdulkhaliq A., and Saba L. Kareem. "Behavior of Curved Steel-Concrete Composite Beams Under Monotonic Load." International Journal of Mathematical, Engineering and Management Sciences 5, no. 6 (December 1, 2020): 1210–33. http://dx.doi.org/10.33889/ijmems.2020.5.6.091.

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The paper develops a numerical investigation on the behavior of steel-concrete composite beam curved in plan to examine the effect of the various parameters. Three-dimensional finite element analysis (FEA) is employed using a commercial software, ABAQUS. The geometric and material nonlinearities are utilized to simulate the composite beam under a monotonic load. The FEA efficiency has been proved by comparing the numerical results with experimental tests obtained from previous literature, including load-deflection curves, ultimate load, ultimate and failure deflection, and cracks propagation. The validated models are used to assess some of the key parameters such the beam span/radius ratio, web stiffeners, partial interaction, concrete compressive strength, and steel beam yield stress. From the obtained results, it is noticed that the span/radius of curvature ratio influences the loading capacity, the beam yielding (i.e. the beam yield at an early stage) when the span/radius ratio increases and inelastic behavior developed early of the beam due to the torsional effect. The presence of web stiffeners with different locations in the curve composite beam affected the shear strength. The web twisting and vertical separation at the beam mid-span are observed to decrease as the number of the stiffeners increase due to the decrease in the beam torsion incorporating with transferring the failure to the concrete slab. Furthermore, the partial interaction and steel beam yield stress developed in this study appear to have a remarkable effect on beam capacity.

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Kowalewski, Zbigniew L., and Tadeusz Szymczak. "On the Effects Associated with Control Parameters Delay during Biaxial Cyclic Loading of Engineering Materials." Materials Science Forum 638-642 (January 2010): 3913–18. http://dx.doi.org/10.4028/www.scientific.net/msf.638-642.3913.

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The paper presents experimental results of investigations carried out on the P91 steel and 2024 aluminium alloy under complex stress states due to various combinations of an axial force and twisting moment. An influence of out-of-phase sinusoidal and trapezoidal strain signals on the mechanical behaviour of tested materials was considered. The experiments enabled identification of the second order effects connected with the non-proportional cyclic loadings such as the phase shift between stress and strain signals during the deformation along the circular strain path, and a significant stress drop of the one of loading components applied in the case of deformation enforced by the trapezoidal signals. The experimental programme also contained the tests of monotonic tensile deformation realized simultaneously with delayed torsional cycles. They enabled to observe a drastic variations of the proportional limit and yield point of the materials in the tensile direction. This fact manifests an important material feature which can be applied to the optimal designing of some metal forming processes like an extrusion or forging for example.

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Zhao, Ernian, Qiang Zhou, Weilian Qu, and Wenming Wang. "Fatigue Properties Estimation and Life Prediction for Steels under Axial, Torsional, and In-Phase Loading." Advances in Materials Science and Engineering 2020 (April 27, 2020): 1–8. http://dx.doi.org/10.1155/2020/8186159.

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In this study, several estimation methods of fatigue properties based on different monotonic mechanical parameters were first discussed. The advantages and disadvantages of the Hardness Method proposed by Roessle and Fatemi were investigated and improved through the analysis of a total of 92 fatigue test data. A new Segment Fitting Method from Brinell hardness was then proposed for the fatigue properties estimation, and a total of 96 pieces of fatigue test data under axial, torsional, and multiaxial in-phase loading were collected to verify the applicability of the new proposal. Finally, the prediction accuracy of the new proposal and three exciting estimation methods was compared with the predictions based on the experimental fatigue properties. Based on the results obtained, the newly proposed estimation method has a significant improvement on the relation between fatigue ductility coefficient and Brinell hardness, which consequently improves the fatigue life prediction accuracy with the scatter band of 2, particularly for the materials with low Brinell hardness. The present study can provide a simplified analysis of the preliminary fatigue design of engineering structures.

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Aziz, M., I. Towhata, S. Yamada, M. U. Qureshi, and K. Kawano. "Water-induced granular decomposition and its effects on geotechnical properties of crushed soft rocks." Natural Hazards and Earth System Sciences 10, no. 6 (June 17, 2010): 1229–38. http://dx.doi.org/10.5194/nhess-10-1229-2010.

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Abstract. The widespread availability of soft rocks and their increasing use as cheap rockfill material is adding more to geotechnical hazards because time-dependent granular decomposition causes significant damage to their mechanical properties. An experimental study was conducted through monotonic torsional shear tests on crushed soft rocks under fully saturated and dry conditions and compared with analogous tests on standard Toyoura sand. Due to the sensitivity of material to disintegration upon submergence, saturated conditions accelerated granular decomposition and, hence, simulated loss of strength with time, whereas, dry test condition represented the response of the soil with intact grains. A degradation index, in relation to gradation analyses after each test, was defined to quantify the degree of granular decomposition. Possible correlations of this index, with strength and deformation characteristics of granular soils, were explored. Enormous volumetric compression during consolidation and monotonic loading of saturated specimens and drastic loss of strength parameters upon submergence were revealed. It is revealed that the observed soil behaviour can be critical for embankments constructed with such rockfill materials. Moreover, the enhanced ability of existing soil mechanics models to predict time-dependent behaviour by incorporating water-induced granular decomposition can simplify several in situ geotechnical problems.

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Tozzi, Chiara, Davide Dalmazzo, Orazio Baglieri, and Ezio Santagata. "Experimental evaluation and modelling of low temperature failure properties of asphalt binders by means of the monotonic torsional loading test." Construction and Building Materials 347 (September 2022): 128344. http://dx.doi.org/10.1016/j.conbuildmat.2022.128344.

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Pamukcu, S. "Shear Modulus of Soft Marine Clays." Journal of Offshore Mechanics and Arctic Engineering 111, no. 4 (November 1, 1989): 265–72. http://dx.doi.org/10.1115/1.3257094.

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Instabilities occur frequently in ocean-bottom sediments where the deposition is faster than the consolidation of the material. Cyclic loading of waves contribute to the existing pore pressures within the sediment reducing the effective stresses. The sediment can lose strength and stability and flow in gullies of depth up to 30 m, on slopes less than 0.5 deg. One theory and some related experiments indicate that, depending on the depositional conditions and state of stress, the failure mechanism for such soft saturated marine clays may not necessarily require large straining of the material. Laboratory determination of low-strain shear behavior or shear modulus of soft marine clays can be complicated if high-frequency dynamic testing methods are utilized. Cyclic loading can promote fast degradation of moduli for these soils even at low strain amplitudes. A monotonic torsional shear device, namely a triaxial vane device, was equipped with a computer-aided data acquisition system to detect low-strain shear deformations under quasi-static loading conditions. The average range of electronically measured strain range was 10−4 to 1 percent, which was compatible with that of a high-frequency, low-strain dynamic testing method, namely, resonant column. Comparison of the dynamic and static moduli reduction curves of artificially prepared soft kaolinite specimens demonstrated the cyclic degradation effects on such clays. The relatively continuous, high-resolution low-strain static data indicated further gain in understanding of low-strain nonlinearity and yielding behavior of soft marine clays.

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Wijewickreme, Dharma, and Yoginder P. Vaid. "Experimental observations on the response of loose sand under simultaneous increase in stress ratio and rotation of principal stresses." Canadian Geotechnical Journal 45, no. 5 (May 2008): 597–610. http://dx.doi.org/10.1139/t08-001.

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The drained response of loose sand (relative density of 30%) under simultaneous increase in principal stress ratio (R = σ'1/σ'3) and the inclination of major principal stress to the vertical (ασ) is examined using data from hollow cylinder torsional shear testing. The study specifically pertains to the behaviour of loose sand subject to monotonic linear stress path loadings in the R–ασ space, within the domain of R ≤ 2, ασ < 45°, while intermediate principal stress parameter (b) and effective mean normal stress (σ'm) are held constant. The relationship between horizontal shear stress (τzt) and horizontal shear strain (γzt) of loose sand under such loadings is shown to be unique and stress-path independent. At any stress state, the horizontal shear stiffness (dτzt/dγzt) for a given σ'm depends only on the current value of τzt, and not on the value of individual components of normal effective stress, or their increments. When R and ασ are increased simultaneously in a linear manner, loose sand initially exhibits linear strain paths, suggesting no significant changes to the inherent anisotropy during the early stages of such loading. The directions of principal stress increment (αΔσ) and principal strain increment (αΔε) are found coincident, when αΔσ < 45°. An approach to predict the response of loose sand under simultaneous increase in R and ασ with constant b and σ'm has been developed based on these findings.

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d'Onofrio, Anna, Anna Chiaradonna, Giuseppe Lanzo, and Mourad Karray. "Cyclic and dynamic behaviour of a Canadian sensitive clay." E3S Web of Conferences 92 (2019): 08003. http://dx.doi.org/10.1051/e3sconf/20199208003.

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Clays with higher undisturbed undrained shear strengths than remoulded strengths are considered sensitive. While the stress-strain behaviour of these clays under monotonic loading condition was widely investigated, few data are available of their behaviour under cyclic and dynamic loading conditions. This paper presents the preliminary results of an experimental program on undisturbed samples of a sensitive clay retrieved at Saint Luc de Vincennes (Quebec). In particular, the paper shows the comparison among the modulus reduction curve, G/G0 - γ and the damping ratio variation with shear strain, D - γ measured using different devices, trying to highlight the main factors influencing the observed behaviour , including sample disturbance and storing method. The tests were carried out using one torsional shear and two different cyclic simple shear devices capable of investigating from small to large shear strains. The tests were carried out by three different laboratories at the Université de Sherbrooke, Canada, the University of Naples Federico II and the Sapienza University of Rome, Italy. Oedometric tests also performed by the three different research teams indicate that the clay samples were carefully shipped and stored, and the soil specimens were accurately prepared. Some differences were observed in the G/G0(γ) and D(γ) curves obtained by different tests, some of them ascribed to the intrinsic anisotropy of the investigated clay.

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Kh. Jasim, Israa, Mazin B. Abdulrahman, Muyasser M. Jomaa'h, Belal Alsubari, Hayder Saadoon Abdulaali, and Shagea Alqawzai. "Torsional Behavior of RC Beams with Transverse Openings Strengthened by Near Surface Mounted-Steel Wire Rope Subjected to Repeated Loading." Tikrit Journal of Engineering Sciences 29, no. 4 (December 25, 2022): 79–89. http://dx.doi.org/10.25130/tjes.29.4.9.

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The presence of the openings negatively effects on the strength of the beams where they act as a weak point because of the sudden change in the cross-section of the beam, so it becomes necessary to make strengthening for the beams to resist the effect of the openings and improve the strength of the beams, especially if the beams are subjected to repeated loads because of its effect on the strength at the failure. This paper studies the effect of the openings on the beams subjected to repeated loading and determine the extent of the increase in the strength of the beams when strengthened by the NSM technique. The experimental program included casting and testing fifteen RC beams, six of them considered as a control beams (three with strengthening and three without strengthening), and nine of them having circular transverse openings in different locations and strengthened by the NSM technique. Every type of beams is tested under three different types of loads (monotonic, constant repeated load, and incremental repeated load). All of the beams have the same dimensions and same reinforcement. The results show that all the beams with transverse openings are affected by repeated loads where the ultimate torque decreases and the twist angle increases. The existence of openings has a noted effect on reducing the ultimate torque, whereas the percentage of decrease in the ultimate torsional capacity reached 43.83% at the beam where the opening location is closest to the support (at the quarter of the clear span) and subjected to constant repeated loads, and the ultimate torque is significantly improved when the opening position is moved away from the supports. Also, the existence of strengthening reduced or eliminated the influence of openings on the ultimate torque compared with related non- strengthened beams.

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Ali, Sarmad Abdulsahab, and John P. Forth. "An experimental and analytical investigation of reinforced concrete beam-column joints strengthened with a range of CFRP schemes applied only to the beam." Advances in Structural Engineering 24, no. 12 (May 10, 2021): 2748–66. http://dx.doi.org/10.1177/13694332211007371.

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This paper investigates the experimental and analytical behaviour of beam-column joints that are subjected to a combination of torque, flexural and direct shear forces, where different Carbon Fibre Polymer (CFRP) strengthening wraps have been applied only to the beam. These wrapping schemes have previously been determined by the research community as an effective method of enhancing the torsional capacities of simply supported reinforced concrete beams. In this investigation, four 3/4-scale exterior beam-column joints were subjected to combined monotonic loading; three different beam wrapping schemes were employed to strengthen the beam region of the joint. The paper suggests a series of rational formulae, based on the space truss mechanism, which can be used to evaluate the joint shear demand of the beams wrapped in these various ways. Further, an iterative model, based on the average stress-strain method, has been introduced to predict joint strength. The proposed analytical approaches show good agreement with the experimental results. The experimental outcomes along with the adopted analytical methods reflect the consistent influence of the wrapping ratio, the interaction between the combined forces, the concrete strut capacity and the fibre orientation on the joint forces, the failure mode and the distortion levels. A large rise in the strut force resulting from shear stresses generated from this combination of forces is demonstrated and leads to a sudden-brittle failure. Likewise, increases in the beams’ main steel rebar strains are identified at the column face, again influenced by the load interactions and the wrapping systems used.

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Demakos, Constantinos B., Constantinos C. Repapis, and Dimitros P. Drivas. "Experimental Investigation of Shear Strength for Steel Fibre Reinforced Concrete Beams." Open Construction & Building Technology Journal 15, no. 1 (May 19, 2021): 81–92. http://dx.doi.org/10.2174/1874836802115010081.

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Aims: The aim of this paper is to investigate the influence of the volume fraction of fibres, the depth of the beam and the shear span-to-depth ratio on the shear strength of steel fibre reinforced concrete beams. Background: Concrete is a material widely used in structures, as it has high compressive strength and stiffness with low cost manufacturing. However, it presents low tensile strength and ductility. Therefore, through years various materials have been embedded inside it to improve its properties, one of which is steel fibres. Steel fibre reinforced concrete presents improved flexural, tensile, shear and torsional strength and post-cracking ductility. Objective: A better understanding of the shear performance of SFRC could lead to improved behaviour and higher safety of structures subject to high shear forces. Therefore, the influence of steel fibres on shear strength of reinforced concrete beams without transverse reinforcement is experimentally investigated. Methods: Eighteen concrete beams were constructed for this purpose and tested under monotonic four-point bending, six of which were made of plain concrete and twelve of SFRC. Two different aspect ratios of beams, steel fibres volume fractions and shear span-to-depth ratios were selected. Results: During the experimental tests, the ultimate loading, deformation at the mid-span, propagation of cracks and failure mode were detected. From the tests, it was shown that SFRC beams with high volume fractions of fibres exhibited an increased shear capacity. Conclusion: The addition of steel fibres resulted in a slight increase of the compressive strength and a significant increase in the tensile strength of concrete and shear resistance capacity of the beam. Moreover, these beams exhibit a more ductile behaviour. Empirical relations predicting the shear strength capacity of fibre reinforced concrete beams were revised and applied successfully to verify the experimental results obtained in this study.

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Kowalewski, Zbigniew L., and Tadeusz Szymczak. "On the Mutual Interactions of Monotonic and Cyclic Loading and their Effect on the Strength of Aluminium Alloys." Applied Mechanics and Materials 24-25 (June 2010): 213–18. http://dx.doi.org/10.4028/www.scientific.net/amm.24-25.213.

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The paper investigates the interaction of monotonic cyclic loading and their effect on the yield strength of aluminium alloy. Two different loading combinations were considered, i.e. torsion-reverse-torsion superimposed on monotonic tension and monotonic torsion combined with tension-compression cycles. All strain controlled tests were carried out at room temperature using thin-walled tubular specimens. The maximum value of the total cyclic strain amplitude was less than 1%. The influence of amplitude, frequency and shape of cyclic loading signal on the proportional limit and conventional yield point was investigated. The experimental results presented in the paper may be useful to designers of structures that utilize manufacturing processes such as drawing, extrusion, forging of selected semi-finished elements or researchers working on the development of new constitutive equations.

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Kumar, R. Suresh, P. Chellapandi, and C. Lakshmana Rao. "Modelling Material Behavior of Austenitic Stainless Steel under Monotonic and Cyclic Loadings." Applied Mechanics and Materials 151 (January 2012): 721–25. http://dx.doi.org/10.4028/www.scientific.net/amm.151.721.

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Mechanical behavior of the austenitic stainless steel under monotonic and cyclic loading at room temperature has been mathematically predicted. Materials like SS 316 LN exhibit cyclic hardening behavior under cyclic loading. Based on the characteristics of yield surface, cyclic hardening can be classified into isotropic and kinematic hardening. Armstrong-Frederic model is used for predicting the kinematic hardening of this material. It is basically a five parameter, nonlinear kinematic hardening model. Cyclic tests for various ranges were carried out to derive the isotropic material parameter required for modeling. Kinematic hardening material parameter required for modeling were computed based on both monotonic tension and torsion tests. By using these parameters the developed program is able to model the mechanical behavior of austenitic stainless steel under monotonic and cyclic loading conditions at room temperature. Comparison of the predicted results with the experimental results shows that the kinematic hardening material parameters derived from the monotonic torsion tests were in good agreement than that of the monotonic tension tests. Also it is recommended to use more material parameter constitutive models to improve the accuracy of the mathematical predictions for the material behavior under cyclic loading.

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Mars, W. V., and A. Fatemi. "Observations of the Constitutive Response and Characterization of Filled Natural Rubber Under Monotonic and Cyclic Multiaxial Stress States." Journal of Engineering Materials and Technology 126, no. 1 (January 1, 2004): 19–28. http://dx.doi.org/10.1115/1.1631432.

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This work explores the monotonic and cyclic behaviors of filled, natural rubber. Results of stress-strain experiments conducted under stress states of simple, planar, and equibiaxial tension are presented. The ability of hyperelastic models to capture the observed response, as well as recent developments in constitutive modeling of filled rubber such as the consequences of the Mullins effect, are discussed. Monotonic and cyclic multiaxial experiments were also conducted using a short, thin-walled, cylindrical specimen subjected to a wide range of combined axial and twist displacements. Experiments included pure axial tension, pure torsion, combined loading in which the axial and torsion displacements varied proportionally, and combined loading in which the axial and torsion displacements varied non-proportionally (phase between axial and torsion channels of ϕ=0 deg, 90 deg, 180 deg). Results from these tests are presented and discussed, including evolution of stress-strain behavior with load cycles, and the effects of a short period of initial overloading on the subsequent evolution of the stress-strain response.

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Orlov, Dmitry, Yoshikazu Todaka, Minoru Umemoto, Yan Beygelzimer, Z. Horita, and Nobuhiro Tsuji. "Plastic Flow and Grain Refinement under Simple Shear-Based Severe Plastic Deformation Processing." Materials Science Forum 604-605 (October 2008): 171–78. http://dx.doi.org/10.4028/www.scientific.net/msf.604-605.171.

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In the present work, effects of loading scheme and strain reversal on structure evolution are studied by using high pressure torsion (HPT) and twist extrusion (TE) techniques. High purity aluminum (99.99%) was processed at room temperature up to a total average equivalent strain of ~4.8 by TE and HPT with two deformation modes: monotonic and reversal deformation with a step of 12˚ rotation. It was revealed that microstructural change with straining observed in pure Al was a common consequence of the SPD processing and was not affected significantly by the loading scheme. At the same time, it was found that strain reversal retarded grain refinement in comparison with monotonic deformation.

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Kim, J., M. Kazama, and Y. Kwon. "Effects of relative density and accumulated shear strain on post-liquefaction residual deformation." Natural Hazards and Earth System Sciences 13, no. 10 (October 18, 2013): 2567–77. http://dx.doi.org/10.5194/nhess-13-2567-2013.

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Abstract. The damage caused by liquefaction, which occurs following an earthquake, is usually because of settlement and lateral spreading. Generally, the evaluation of liquefaction has been centered on settlement, that is, residual volumetric strain. However, in actual soil, residual shear and residual volumetric deformations occur simultaneously after an earthquake. Therefore, the simultaneous evaluation of the two phenomena and the clarification of their relationship are likely to evaluate post-liquefaction soil behaviors more accurately. Hence, a quantitative evaluation of post-liquefaction damage will also be possible. In this study, the effects of relative density and accumulated shear strain on post-liquefaction residual deformations were reviewed through a series of lateral constrained-control hollow cylindrical torsion tests under undrained conditions. In order to identify the relationship between residual shear and residual volumetric strains, this study proposed a new test method that integrates monotonic loading after cyclic loading, and K0-drain after cyclic loading – in other words, the combination of cyclic loading, monotonic loading, and the K0 drain. In addition, a control that maintained the lateral constrained condition across all the processes of consolidation, cyclic loading, monotonic loading, and drainage was used to reproduce the anisotropy of in situ ground. This lateral constrain control was performed by controlling the axial strain, based on the assumption that under undrained conditions, axial and lateral strains occur simultaneously, and unless axial strain occurs, lateral strain does not occur. The test results confirmed that the recovery of effective stresses, which occur during monotonic loading and drainage after cyclic loading, respectively, result from mutually different structural restoration characteristics. In addition, in the ranges of 40–60% relative density and 50–100% accumulated shear strain, relative density was found to have greater effects than the number of cycles (accumulated shear strain).

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Szymczak, T., and Z. Kowalewski. "Variations of Mechanical Parameters and Strain Energy Dissipated During Tension-Torsion Loading." Archives of Metallurgy and Materials 57, no. 1 (March 1, 2012): 193–97. http://dx.doi.org/10.2478/v10172-012-0009-4.

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Variations of Mechanical Parameters and Strain Energy Dissipated During Tension-Torsion LoadingThe paper presents behaviour of materials under complex loading being combinations of torsion-reverse-torsion cycles superimposed on monotonic tensile deformation. The 2024 aluminium alloy, P91 steel and M1E copper were investigated under plane stress state using thin-walled tubular specimens. All tests were strain controlled and a total strain was less than 1%. An influence of torsion cycles on tensile characteristic was manifested by lowering of the proportional limit and yield point. This effect was increased with magnification of cyclic strain amplitude and in the case of copper a reduction of yield point was equal around 90%. A character of this effect was checked using the yield surface concept after each test. The papers also presents, variations of tangential hardening modulus and plastic strain energy dissipation.

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Kobayashi, Masami, Koji Uetani, and Tomohiro Mikami. "The Occurrence Limit of Strain Nonuniformity in Thin-Walled Cylinders Subjected to Cyclic Torsion." Key Engineering Materials 340-341 (June 2007): 1411–16. http://dx.doi.org/10.4028/www.scientific.net/kem.340-341.1411.

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The symmetry limit theory for 3-D continua developed by the authors, is applied to predictions of the occurrence limit of nonuniform strain in cylinders subjected to cyclic torsion. Bifurcation analysis of a steady-state path, which was defined as a continuous sequence of steady states generated under continuous increasing amplitude cyclic loading, is performed for the cylinder model. The deformation mode with very short wavelength in the circumferential direction is obtained, analogous to that in the internal buckling of a rigidly confined continuum shown by Biot. It is shown that this circumferential short-wave mode occurs at much smaller amplitude than the bifurcation under monotonic torsion.

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Evans, W. J., and F. R. Eng. "Microstructure and Texture in an Alpha/Beta Titanium Alloy and their Impact on Mechanical Response." Materials Science Forum 539-543 (March 2007): 3589–94. http://dx.doi.org/10.4028/www.scientific.net/msf.539-543.3589.

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The paper explores texture in the titanium alloys Ti-6-4 and Ti 550. It illustrates how texture evolves under plane strain compression in Ti-6-4. This evolution is dependent on temperature, degree of reduction (strain) and strain rate. Rolled (Ti-6-4) and forged (Ti 550) variants with different textures are then examined under tension and torsion loading in relation to their monotonic and fatigue response. Correlation of the observations with regard to orientation of the basal plane is demonstrated.

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Wang, Jing Feng, Bo Wang, and Zhong Ming Zheng. "Static Experimental Study on Composite Beam with Concrete filled Steel Tubular Truss." Advanced Materials Research 374-377 (October 2011): 1680–84. http://dx.doi.org/10.4028/www.scientific.net/amr.374-377.1680.

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To research the mechanical behaviour of the novel composite beam with concrete filled steel tubular (CFST) truss, an experimental study of simple composite beam subjected to monotonic loading is described. A test program was developed to investigate failure models and working mechanism of the typed composite structure. Load-deformation curves, deflection regulation, strain distribution of beam were analyzed and asserted. The experimental and analytic results show that the typed composite beam has high strength, excellent ductility, and torsion performance. It can be used the large span bridges and high rise buildings.

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Yaguchi, Masatsugu, Masato Yamamoto, Takashi Ogata, and Nobutada Ohno. "An Anisotropic Constitutive Model for a Directionally Solidified Superalloy." Key Engineering Materials 340-341 (June 2007): 901–6. http://dx.doi.org/10.4028/www.scientific.net/kem.340-341.901.

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The monotonic tensile and creep deformations of a directionally solidified (DS) superalloy are investigated for several loading directions. The material exhibits remarkable anisotropy under elastic and creep loading conditions, whereas it shows isotropy under loading conditions of high strain rates. Tension-torsion creep tests are also conducted to investigate the deformation under multiaxial stress conditions. Referring to the observed behavior, a unified constitutive model, which has two features, is developed for the DS superalloy. One is a static recovery term of back stresses that is prescribed as a transversely isotropic property, which is supposed to have an effect on the deformation behavior under creep loading conditions. The other is the division of inelastic strain into two components, which represent octahedral and cubic slip system deformations, so as to describe multiaxial creep deformation. Calculation results obtained using the constitutive model are compared with the uniaxial and multiaxial experimental results to evaluate the validity of the model.

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Ma, Xinkai, Fuguo Li, Jun Cao, Jinghui Li, Han Chen, and Chen Zhao. "Vickers microhardness and microstructure relationship of Ti-6Al-4V alloy under cyclic forward-reverse torsion and monotonic torsion loading." Materials & Design 114 (January 2017): 271–81. http://dx.doi.org/10.1016/j.matdes.2016.11.028.

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Moreno, Belen, Pablo Lopez-Crespo, Antonio González-Herrera, and Jose Zapatero. "Multiaxial Fatigue Evaluation of ST52-3N Structural Steel." Key Engineering Materials 452-453 (November 2010): 41–44. http://dx.doi.org/10.4028/www.scientific.net/kem.452-453.41.

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Many mechanical components are subjected to multiaxial fatigue. These conditions are typically coming from external loads, the geometry of the component and/or residual stresses. However the majority of experimental data available in the literature are focused on the simpler uni-axial fatigue problem. The present work describes a series of experimental tests conducted to characterise in a comprehensive way the multiaxial behaviour of a ST52-3N structural steel. First, the monotonic properties of the steel were obtained experimentally. Then cyclic properties were also measured both in the longitudinal and torsional axes. Finally another series of tests were carried out to study the multiaxial response of the material. Both in-phase (proportional) and out-of-phase (non proportional) loadings were employed, thus providing a complete database for improving current models which describe the multiaxial behaviour of materials.

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Kořínek, Michal, Radim Halama, František Fojtík, Marek Pagáč, Jiří Krček, David Krzikalla, Radim Kocich, and Lenka Kunčická. "Monotonic Tension-Torsion Experiments and FE Modeling on Notched Specimens Produced by SLM Technology from SS316L." Materials 14, no. 1 (December 23, 2020): 33. http://dx.doi.org/10.3390/ma14010033.

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The aim of this work was to monitor the mechanical behavior of 316L stainless steel produced by 3D printing in the vertical direction. The material was tested in the “as printed” state. Digital Image Correlation measurements were used for 4 types of notched specimens. The behavior of these specimens under monotonic loading was investigated in two loading paths: tension and torsion. Based on the experimental data, two yield criteria were used in the finite element analyses. Von Mises criterion and Hill criterion were applied, together with the nonlinear isotropic hardening rule of Voce. Subsequently, the load-deformation responses of simulations and experiments were compared. Results of the Hill criterion show better correlation with experimental data. The numerical study shows that taking into account the difference in yield stress in the horizontal direction of printing plays a crucial role for modeling of notched geometries loaded in the vertical direction of printing. Ductility of 3D printed specimens in the “as printed” state is also compared with 3D printed machined specimens and specimens produced by conventional methods. “As printed” specimens have 2/3 lower ductility than specimens produced by a conventional production method. Machining of “as printed” specimens does not affect the yield stress, but a significant reduction of ductility was observed due to microcracks arising from the pores as a microscopic surface study showed.

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Liu, Yan Zi, Zheng Liu, Jiong Li, and Xin Chen. "Material Strain Analysis of CFRP Reinforced RC Columns Subjected to Combined Action of Force by Finite Element Method." Applied Mechanics and Materials 226-228 (November 2012): 991–94. http://dx.doi.org/10.4028/www.scientific.net/amm.226-228.991.

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Using the finite element software ANSYS to analyze the CFRP strengthened concrete columns.The concrete columns are in the axial force existence situation, many columns should be reinforced by longitudinal and circumferential CFRP because of insufficient capacity. Subject to loading,11 root columns were designed, aiming to the layer number of CFRP, the location and orientation of CFRP, the eccentric distant of specimens.One of them is a non-reinforcement column.Under compression, bending, shearing and monotonic torsion, the nonlinear finite element model was established to test stressed steel bar in column test specimens, including longitudinal tensile reinforcement, longitudinal compression reinforcement and stirrup, as well as CFRP has been analyzed, including stress changing of longitudinal CFRP and transverse CFRP. The torque-strain curves for relationship were discussed among longitudinal reinforcement, stirrup and CFRP.

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Lanz, O., R. McLaughlin, S. Elder, S. Werre, and D. Filipowicz. "A biomechanical comparison of 3.5 locking compression plate fixation to 3.5 limited contact dynamic compression plate fixation in a canine cadaveric distal humeral metaphyseal gap model." Veterinary and Comparative Orthopaedics and Traumatology 22, no. 04 (2009): 1–8. http://dx.doi.org/10.3415/vcot-08-05-0042.

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Summary3.5 locking compression plate (LCP) fixation was compared to 3.5 limited contact dynamic compression plate (LC-DCP) fixation in a canine cadaveric, distal humeral metaphyseal gap model. Thirty paired humeri from adult, large breed dogs were separated into equal groups based on testing: static compression, cyclic compression, and cyclic torsion. Humeral constructs stabilized with LCP were significantly stiffer than those plated with LCDCP when loaded in static axial compression (P = 0.0004). When cyclically loaded in axial compression, the LCP constructs were significantly less stiff than the LC-DCP constructs (P = 0.0029). Constructs plated with LCP were significantly less resistant to torsion over 500 cycles than those plated with LC-DCP (P<0.0001). The increased stiffness of LCP constructs in monotonic loading compared to constructs stabilised with non-locking plates may be attributed to the stability afforded by the plate-screw interface of locking plates. The LCP constructs demonstrated less stiffness in dynamic testing in this model, likely due to plate-bone offset secondary to non-anatomic contouring and occasional incomplete seating of the locking screws when using the torque-limiting screw driver. Resolution of these aspects of LCP application may help improve the stiffness of fixation in fractures modeled by the experimental set-up of this investigation.

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Bonifaz, E. A., Juan Baus, and Eva O. L. Lantsoght. "Modeling Concrete Material Structure: A Two-Phase Meso Finite Element Model." Journal of Multiscale Modelling 08, no. 02 (May 4, 2017): 1750004. http://dx.doi.org/10.1142/s1756973717500044.

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Concrete is a compound material where aggregates are randomly placed within the cement paste. To describe the behavior of concrete structures at the ultimate, it is necessary to use nonlinear finite element models, which for shear and torsion problems do not always give satisfactory results. The current study aims at improving the modeling of concrete at the meso-level, which eventually can result in an improved assessment of existing structures. Concrete as a heterogeneous material is modeled consisting of hydrated cement paste and aggregates. The stress–strain curves of the hydrated cement paste and aggregates are described with results from the literature. A three-dimensional (3D) finite element model was developed to determine the influence of individual phases on the inelastic stress–strain distribution of concrete structures. A random distribution and morphology of the cement and aggregate fractions are achieved by using DREAM.3D. Two affordable computational dual-phase representative volume elements (RVEs) are imported to ABAQUS to be studied in compression and tension. The virtual specimens (concrete mesh) subjected to continuous monotonic strain loading conditions were constrained with 3D boundary conditions. Results demonstrate differences in stress–strain mechanical behavior in both compression and tension test simulations. A strong dependency of flow stress and plastic strain on phase type, aggregate (andesite) size, shape and distribution upon the composite local response are clearly observed. It is noted that the resistance to flow is higher in concrete meshes composed of finer and homogeneous aggregate particles because the Misses stresses and effective plastic strains are better distributed. This study shows that at the meso-level, concrete can be modeled consisting of aggregates and hydrated cement paste.

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Langstädtler, Lasse, Sebastian Schnabel, Marius Herrmann, Christian Schenck, and Bernd Kuhfuss. "Short-Term Material Characterization by Electrohydraulic Incremental Extrusion through Micro Channels." Materials 14, no. 3 (January 22, 2021): 525. http://dx.doi.org/10.3390/ma14030525.

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Conventional testing procedures for characterizing the mechanical behavior of materials require intense preparation in geometry and in the handling of the samples to apply specific stress conditions. Furthermore, these procedures are time consuming. In a novel method for high-throughput development of new material, spherical and cylindrical micro samples should also be tested within a short time. For mechanical testing, the samples need to be exposed to specific types of stress. As most conventional testing procedures are not applicable, new testing procedures are demanded. The incremental electrohydraulic extrusion of micro samples through micro channels is a new testing procedure that was introduced for short-term material characterization. Loading energy is used to cause shock waves that incrementally push the samples through the forming die. The resulting deformation progress is measured between the forming steps. In this research, process simulations are used for channel design and material flow analysis. The designed channels that cause specific stress in samples are realized by stacking elements radially or axially. The stacking enables sample access for measurement and unloading and ensures good machinability of the forming channels. New testing cases for short-term characterization of cylindrical as well as spherical micro samples by electrohydraulic extrusion are presented according to monotone tensile, compression, and torsion testing. Furthermore, production-related testing and cyclic load testing are introduced by incremental electrohydraulic extrusion. By measuring the deformation due to the dependence on supplied energy, flow curve equivalents are determined that correspond to values from conventional material testing procedures.

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Khayat, Navid. "MONOTONIC BEHAVIOUR OF SAND UNDER TORSIONAL LOADING WITH DIFFERENT CONFINE STRESS." International Journal of GEOMATE 14, no. 43 (March 1, 2018). http://dx.doi.org/10.21660/2018.43.7359.

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Subramaniam, Kolluru V., John S. Popovics, and Surendra P. Shah. "Monitoring Fatigue Damage In Concrete." MRS Proceedings 503 (1997). http://dx.doi.org/10.1557/proc-503-151.

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ABSTRACTRigid airport pavement structures suffer damage from multi-axial high magnitude cyclic stresses resulting from passing heavy aircraft. It is of interest to model the response of plain portland cement concrete to such loading conditions; thus, the sensitive detection and characterization of such damage during the loading process is important. Low strain vibrational resonance frequency measurement offers direct information concerning the global, apparent elastic moduli of the material and preliminary results have shown such measurements are sensitive to the presence of damage in concrete.The work reported here includes the theoretical foundation and experimental results of a non-destructive technique, based on vibrational resonance measurement. The tests are applied to monitor damage imparted to end-mounted hollow concrete cylinders subjected to monotonic and cyclic torsional (bi-axial) loads. An introduction to the concepts of vibration testing and details of mechanical and vibrational test procedures employed are given first. The most significant vibrational modes, of all of the possible modes setup within the specimen, are identified. The frequency value of these significant modes in the concrete specimen are experimentally obtained throughout a controlled cyclic testing procedure to failure. The behavior of these modes is then monitored during a controlled cyclic testing procedure to failure. Distinctions between the frequency values of the various excited resonance modes are noted. Moreover, effects of the two damage types (monotonic and cyclic) on the frequency values of the modes are studied. Finally, conclusions concerning the applicability of the vibrational resonance techniques for monitoring imparted damage in these concrete specimens are drawn.

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Gao, Zengliang, Tianwen Zhao, Xiaogui Wang, and Yanyao Jiang. "Multiaxial Fatigue of 16MnR Steel." Journal of Pressure Vessel Technology 131, no. 2 (December 11, 2008). http://dx.doi.org/10.1115/1.3008041.

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Uniaxial, torsion, and axial-torsion fatigue experiments were conducted on a pressure vessel steel, 16MnR, in ambient air. The uniaxial experiments were conducted using solid cylindrical specimens. Axial-torsion experiments employed thin-walled tubular specimens subjected to proportional and nonproportional loading. The true fracture stress and strain were obtained by testing solid shafts under monotonic torsion. Experimental results reveal that the material under investigation does not display significant nonproportional hardening. The material was found to display shear cracking under pure shear loading but tensile cracking under tension-compression loading. Two critical plane multiaxial fatigue criteria, namely, the Fatemi–Socie criterion and the Jiang criterion, were evaluated based on the experimental results. The Fatemi–Socie criterion combines the maximum shear strain amplitude with a consideration of the normal stress on the critical plane. The Jiang criterion makes use of the plastic strain energy on a material plane as the major contributor to the fatigue damage. Both criteria were found to correlate well with the experiments in terms of fatigue life. The predicted cracking directions by the criteria were less satisfactory when comparing with the experimentally observed cracking behavior under different loading conditions.

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Abdullah, Muhammad U., Zulfiqar A. Khan, Wolfram Kruhoeffer, and Toni Blass. "A 3D Finite Element Model of Rolling Contact Fatigue for Evolved Material Response and Residual Stress Estimation." Tribology Letters 68, no. 4 (November 4, 2020). http://dx.doi.org/10.1007/s11249-020-01359-w.

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AbstractRolling bearing elements develop structural changes during rolling contact fatigue (RCF) along with the non-proportional stress histories, evolved residual stresses and extensive work hardening. Considerable work has been reported in the past few decades to model bearing material hardening response under RCF; however, they are mainly based on torsion testing or uniaxial compression testing data. An effort has been made here to model the RCF loading on a standard AISI 52100 bearing steel with the help of a 3D Finite Element Model (FEM) which employs a semi-empirical approach to mimic the material hardening response evolved during cyclic loadings. Standard bearing balls were tested in a rotary tribometer where pure rolling cycles were simulated in a 4-ball configuration. The localised material properties were derived from post-experimental subsurface analysis with the help of nanoindentation in conjunction with the expanding cavity model. These constitutive properties were used as input cyclic hardening parameters for FEM. Simulation results have revealed that the simplistic power-law hardening model based on monotonic compression test underpredicts the residual generation, whereas the semi-empirical approach employed in current study corroborated well with the experimental findings from current research work as well as literature cited. The presence of high compressive residual stresses, evolved over millions of RCF cycles, showed a significant reduction of maximum Mises stress, predicting significant improvement in fatigue life. Moreover, the predicted evolved flow stresses are comparable with the progression of subsurface structural changes and be extended to develop numerical models for microstructural alterations. Graphic Abstract

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Zhu, Xianyun, Yuqian Wang, Luiz Carneiro, Huamiao Wang, and Yanyao Jiang. "Evaluation of elastic-viscoplastic self-consistent models for a rolled AZ31B magnesium alloy under monotonic loading along five different material orientations and free-end torsion." Journal of Magnesium and Alloys, September 2021. http://dx.doi.org/10.1016/j.jma.2021.07.023.

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Journal articles on the topic 'Monotonic torsional loading'

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