Journal articles: 'Thermo-mechanical cyclic loading'

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Ohno, Nobutada, Ryohei Yamamoto, and Dai Okumura. "Thermo-Mechanical Cyclic Plastic Behavior of 304 Stainless Steel at Large Temperature Ranges." Key Engineering Materials 725 (December 2016): 275–80. http://dx.doi.org/10.4028/www.scientific.net/kem.725.275.

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Thermo-mechanical cyclic experiments on 304 stainless steel were performed at several temperature ranges which had maximum temperatures ranging from 350°C to 1000°C and a minimum temperature of 150 °C. Related isothermal cyclic experiments were also performed. Temperature-history dependent cyclic hardening significantly occurred under thermo-mechanical cyclic loading with maximum temperatures around 600°C, whereas almost no cyclic hardening was observed when the maximum temperature was 1000°C. The observed thermo-mechanical cyclic plastic behavior in the saturated state of cyclic hardening was then simulated using a cyclic viscoplastic constitutive model, leading to the following findings. It was difficult to predict the saturated thermo-mechanical cyclic behavior using only the isothermal cyclic experimental data. The saturated thermo-mechanical cyclic behavior was simulated well by introducing a cyclic hardening parameter depending on the maximum temperature. This means that the cyclic hardening parameter should not change with temperature but depend on the maximum temperature in the saturated state of cyclic hardening under thermo-mechanical cyclic loading.

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Sehitoglu, Huseyin. "Material Behavior Under Thermal Loading." Journal of Pressure Vessel Technology 108, no. 1 (February 1, 1986): 113–19. http://dx.doi.org/10.1115/1.3264744.

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Material behavior under thermo-mechanical and isothermal loading cases is studied. The influence of constraint on thermo-mechanical deformation behavior is identified using a two-bar structure. Some of the possible microstructural mechanisms that may be operative under thermo-mechanical loading conditions are discussed. Isothermal tests are reported in the temperature range 20 to 600°C. Additional isothermal tests with step increases and decreases in temperature are performed to study the influence of temperature history on material behavior. During these tests, transient material behavior indicated temperature-strain history effects. Constitutive equations that capture essential features of material behavior under isothermal and thermo-mechanical loading cases are examined. Preliminary predictions of cyclic stress-strain loops are compared to experimental response. Further work is needed to incorporate temperature-strain history effects into constitutive equations.

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Hailemariam, Henok, and Frank Wuttke. "Cyclic mechanical stability of thermal energy storage media." E3S Web of Conferences 205 (2020): 07008. http://dx.doi.org/10.1051/e3sconf/202020507008.

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Closing the gap between supply and demand of energy is one of the biggest challenges of our era. In this aspect, thermal energy storage via borehole thermal energy storage (BTES) and sensible heat storage systems has recently emerged as a practical and encouraging alternative in satisfying the energy requirements of household and industrial applications. The majority of these heat energy storage systems are designed as part of the foundation or sub-structure of buildings with load bearing capabilities, hence their mechanical stability should be carefully studied prior to the design and operation phases of the heat storage system. In this study, the cyclic mechanical performance of a commercial cement-based porous heat storage material is analyzed under different amplitudes of cyclic loading and medium temperatures using a recently developed cyclic thermo-mechanical triaxial device. The results show a significant dependence of the cyclic mechanical behavior of the material, such as in the form of cyclic axial and accumulated plastic strains, on the different thermo-mechanical loading schemes.

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Koeberl, Hubert, Gerhard Winter, Martin Riedler, and Wilfried Eichlseder. "Failure Mechanism of Pure Nickel (Ni 200/201) under Thermo-Mechanical Loading." Key Engineering Materials 348-349 (September 2007): 793–96. http://dx.doi.org/10.4028/www.scientific.net/kem.348-349.793.

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Cyclic loading of metallic engineering components at constant elevated or fluctuating temperature causes a complex evolution of damage which be can hardly be described in a unique and straightforward manner. Often the thermal behaviour of the base metals is to weak, so thermal barrier coatings were needed. Nickel is generally used for such thermal barrier coatings. Therefore it is necessary to study the thermo-mechanical fatigue (TMF) of this material. The lifetime of these coatings is very strong affected by the temperature loading in general, both described by nodal temperatures and their local gradient. The thermal cyclic loading takes place as thermo-mechanical and low cycle fatigue (LCF) damage regime. To classify the thermo-mechanical failure mechanism of pure nickel, OP (out of phase) and IP-TMF (in phase) test series were examined. The use of damage parameters like the unified energy approach make sense, a more detailed life time calculation for pure Nickel can be done by using the Neu-Sehitoglu model. Summary, thermomechanical loadings activate multiple damage mechanism. Surface embrittlement by oxidation is the major distinctive mechanism in addition to pure fatigue damage. Different lifetime approaches were tested and analysed to fulfil the requirements for the fatigue analysis of nickel made components.

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Saad, Abdullah Aziz, Wei Sun, and Abdul Latif M. Tobi. "Multiaxial Viscoplasticity Modelling of Power Plant Steel." Key Engineering Materials 701 (July 2016): 230–34. http://dx.doi.org/10.4028/www.scientific.net/kem.701.230.

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The thermo-mechanical fatigue (TMF) of power plant components is caused by the cyclic operation of power plant. A time-dependent plasticity model can be used to simulate the component response under cyclic thermo-mechanical loading. This paper is concerned with the modelling of thermo-mechanical behaviour of power plant steel under various loading conditions. Fully-reversed, strain-controlled tests were conducted on a parent material of P91 steel at high temperatures in order to determine material constants. A unified, Chaboche viscoplasticity model, was used to model the TMF behaviour of the steel. The multiaxial form of the Chaboche constitutive equations have been implemented in the finite element software and validated by comparing to experimental data. Simulation results have been compared with the results of anisothermal cyclic testing in order to validate the performance of the model in cyclic temperature conditions. The model’s performance under multiaxial stress conditions was investigated by testing and simulating the notched bar specimen under load-controlled conditions.

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Prakash, R. V., T. Pravin, T. Kathirvel, and Krishnan Balasubramaniam. "Thermo-mechanical measurement of elasto-plastic transitions during cyclic loading." Theoretical and Applied Fracture Mechanics 56, no. 1 (August 2011): 1–6. http://dx.doi.org/10.1016/j.tafmec.2011.09.001.

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Hailemariam, Henok, and Frank Wuttke. "Cyclic Mechanical Behavior of Two Sandy Soils Used as Heat Storage Media." Energies 13, no. 15 (July 26, 2020): 3835. http://dx.doi.org/10.3390/en13153835.

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In this research, the cyclic mechanical behavior of two heat storage sandy soils is experimentally studied using a cyclic thermo-mechanical triaxial device. The results of the tests, which were performed under controlled temperature conditions between 20 and 60 °C, show a significant dependence of the mechanical response of the sandy soils with the amplitude of the cyclic loading and medium temperature. The mechanical performance and accumulation of plastic strains of the soils with an increasing number of loading cycles are discussed in view of the intrinsic soil behavior.

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Li, Dao-Hang, De-Guang Shang, Jin Cui, Luo-Jin Li, Ling-Wan Wang, Cheng-Cheng Zhang, and Bo Chen. "Fatigue–oxidation–creep damage model under axial-torsional thermo-mechanical loading." International Journal of Damage Mechanics 29, no. 5 (November 19, 2019): 810–30. http://dx.doi.org/10.1177/1056789519887217.

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A fatigue–oxidation–creep damage model that can take into account the effect of multiaxial cyclic feature on the damage mechanism is proposed under axial-torsional thermo-mechanical fatigue loading. In the proposed model, the effects of non-proportional additional hardening on fatigue, oxidation, and creep damages are considered, and the variation of oxidation damage under different high temperature loading conditions is also described. Moreover, the intergranular creep damage needs to be equivalent to the transgranular damage before accumulating with the fatigue and oxidation damages. The fatigue, oxidation, and creep damages can be expressed as the fractions of fatigue life, critical crack length, and creep rupture time, respectively, which allows the linear accumulation of different types of damages on the basis of life fraction rule. In addition, the proposed model is validated by various fatigue experimental results, including uniaxial thermo-mechanical fatigue, axial-torsional thermo-mechanical fatigue, and isothermal axial-torsional fatigue under proportional and non-proportional loadings. The results showed that the errors are within a factor of 2.

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Kumar, Ritesh, Akhilendra Singh, and Mayank Tiwari. "Investigation of crack repair using piezoelectric material under thermo-mechanical loading." Journal of Intelligent Material Systems and Structures 31, no. 19 (July 29, 2020): 2243–60. http://dx.doi.org/10.1177/1045389x20943946.

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This article presents an experimental investigation of repair of a crack in a structure using piezoelectric material under thermo-mechanical loading environment. The cyclic mechanical load is applied on a plate with a straight and angular crack under uniform temperature environment. Two cases have been considered for the repair of crack under (a) mechanical loading and (b) thermo-mechanical loading environment. A piezoelectric sensor is utilized to measure voltage. The measured voltage is used to calculate the stress intensity factor in passive and active modes. The effect of a single and double piezoelectric patch in the repair of the plate is investigated. The double piezoelectric patch is found to be more effective as compared to single patch when placed symmetrically offset from the crack. An optimal value of voltage and phase difference is evaluated for most effective crack repair. Location of the piezoelectric patch is varied with respect to crack location, and best-suited position for effective crack repair is proposed. The viability of piezoelectric used for repair under thermo-mechanical loading is discussed. The active mode of repair by piezoelectric is found to be effective under thermo-mechanical loading environment.

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COCKS, A. C. F., and F. A. LECKIE. "PERFORMANCE DIAGRAMS FOR CERAMIC MATRIX COMPOSITE COMPONENTS SUBJECTED TO CYCLIC THERMO-MECHANICAL LOADING." Journal of Multiscale Modelling 01, no. 03n04 (July 2009): 433–50. http://dx.doi.org/10.1142/s1756973709000165.

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Ceramic matrix composites (CMCs) are candidates for pressurized tubes which operate under conditions of severe cyclic thermal loading. Simple models describing the properties of CMCs are used to estimate the behaviour of a pressurized tube subjected to cyclic thermal loading and to establish shakedown and failure conditions. Analytical procedures are described which evaluate the component response in the cyclic state. The approach is illustrated by analysing the classical Bree problem assuming material properties which are representative of a SiC/SiC composite. Performance diagrams are presented which identify safe operating conditions and the extent of damage in the component.

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Sehitoglu, Huseyin, and M. Karasek. "Observations of Material Behavior Under Isothermal and Thermo-Mechanical Loading." Journal of Engineering Materials and Technology 108, no. 2 (April 1, 1986): 192–98. http://dx.doi.org/10.1115/1.3225860.

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Deformation and damage behavior of a 1070 steel (class U wheel steel) under thermo-mechanical and isothermal loading have been examined. Fatigue lives under thermo-mechanical and isothermal loading were compared for similar conditions of strain and temperature. For most cases, maximum tensile stresses developed in thermo-mechanical tests exceeded those obtained under isothermal conditions (at Tmin) for the same strain amplitude. Cyclic hardening was observed at 200 to 300°C in isothermal tests. Under thermo-mechanical loading, static strain aging resulted in added hardening due to alternate exposure of the material to high and low temperatures. When thermal recovery effects become dominant at the high temperature end, strengthening upon cooling was suppressed. Oxide scales readily formed at high temperatures (≥400°C) and resulted in an increase in damage accumulation rates. Oxygen penetration into crack flanks and the ensuing loss of carbon was identified using Auger spectroscopy. The severity of oxide penetration into the base metal increased with increase in surface crack density, longer oxidation times and higher temperatures.

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Ghorbel, Elhem. "Interface degradation in metal-matrix composites under cyclic thermo-mechanical loading." Composites Science and Technology 57, no. 8 (1997): 1045–56. http://dx.doi.org/10.1016/s0266-3538(96)00172-8.

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Pierantoni, M., M. De Monte, D. Papathanassiou, N. De Rossi, and M. Quaresimin. "Viscoelastic material behaviour of PBT-GF30 under thermo-mechanical cyclic loading." Procedia Engineering 10 (2011): 2141–46. http://dx.doi.org/10.1016/j.proeng.2011.04.354.

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Li, Dao-Hang, De-Guang Shang, Zhi-Gao Li, Jin-Jie Wang, Jie Hui, Xiao-Dong Liu, Zhi-Qiang Tao, Cheng-Cheng Zhang, and Bo Chen. "Unified viscoplastic constitutive model under axial-torsional thermo-mechanical cyclic loading." International Journal of Mechanical Sciences 150 (January 2019): 90–102. http://dx.doi.org/10.1016/j.ijmecsci.2018.09.046.

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15

Scalet, Giulia, Anargyros Karakalas, Lei Xu, and Dimitris Lagoudas. "Finite Strain Constitutive Modelling of Shape Memory Alloys Considering Partial Phase Transformation with Transformation-Induced Plasticity." Shape Memory and Superelasticity 7, no. 2 (June 2021): 206–21. http://dx.doi.org/10.1007/s40830-021-00330-5.

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AbstractThis paper presents a unified modelling effort to describe partial phase transformation during cyclic thermo-mechanical loading in Shape Memory Alloys (SMA). To this purpose, a three-dimensional (3D) finite strain constitutive model considering TRansformation-Induced Plasticity (TRIP) is combined with a modified hardening function to enable the accurate and efficient prediction of partial transformations during cyclic thermo-mechanical loading. The capabilities of the proposed model are demonstrated by predicting the behavior of the material under pseudoelastic and actuation operation using finite element analysis. Numerical results of the modified model are presented and compared with the original model without considering the partial transformation feature as well as with uniaxial actuation experimental data. Various aspects of cyclic material behavior under partial transformation are analyzed and discussed for different SMA systems.

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Meguid, S. A., G. Shagal, J. C. Stranart, K. M. Liew, and L. S. Ong. "Relaxation of Peening Residual Stresses Due to Cyclic Thermo-Mechanical Overload." Journal of Engineering Materials and Technology 127, no. 2 (April 1, 2005): 170–78. http://dx.doi.org/10.1115/1.1867986.

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Shot-peening induced residual stresses can be relaxed due to cyclic loading. This relaxation plays an important role in determining the fatigue life of the peened components. It is therefore the purpose of this study to conduct comprehensive three-dimensional dynamic elasto-plastic finite element analysis of the joint peening treatment and relaxation process. In this regard, a novel symmetry cell is developed and used to model the multiple impact indentations resulting from multiple impingements of a cluster of shots. The model was further extended to integrate the relaxation resulting from cyclic loading at stresses above the yield strength of the material. This integrated model accounts for the main features of both stages by considering strain-rate effects, shot and target inertia and the dependence of the mechanical properties of the target material on temperature. A wide spectra of cyclic mechanical and thermal loads as well as their combinations is considered and the resulting relaxed residual stress field is determined. As an application, the model was used to predict the residual stress relaxation in a high-strength steel target made from AISI 4340 under different peening and thermomechanical cyclic overload.

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Rui, Yi, and Mei Yin. "Investigations of pile–soil interaction under thermo-mechanical loading." Canadian Geotechnical Journal 55, no. 7 (July 2018): 1016–28. http://dx.doi.org/10.1139/cgj-2017-0091.

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Thermo-active piles that couple load bearing with ground source heat pump systems are one of the new technologies in geotechnical engineering. This paper investigates the pile–soil interaction behaviour of a thermo-active pile in overconsolidated London clay by conducting a thermo-hydro-mechanical finite element analysis using an advanced soil constitutive model. Negative and positive excess pore pressures are computed around the pile during cooling and heating, respectively. However, the difference in the radial effective stress acting on the pile–soil interface between the cooling and heating stages is small, and the pile–soil interaction is governed by the shear mobilization associated with thermally induced cyclic movements of pile expansion and contraction. During the first cooling stage, the shear stress at a small portion in the upper part of the pile reaches close to the yield values, which leads to an additional settlement about 3 mm from the original mechanical load–induced settlement of 2 mm. The shear stresses in subsequent heating and cooling cycles are much smaller than the ultimate shear stress values, because of the heavily overconsolidated nature of the London clay.

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Mao, Jianghui, Carlos Engler-Pinto, Xuming Su, and Scott Kenningley. "Cyclic Behavior of an Al-Si-Cu Alloy under Thermo-Mechanical Loading." SAE International Journal of Materials and Manufacturing 7, no. 3 (April 1, 2014): 602–8. http://dx.doi.org/10.4271/2014-01-1012.

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Arzanfudi, Mehdi M., Rafid Al-Khoury, L. J. Sluys, and G. M. A. Schreppers. "A thermo-hydro-mechanical model for energy piles under cyclic thermal loading." Computers and Geotechnics 125 (September 2020): 103560. http://dx.doi.org/10.1016/j.compgeo.2020.103560.

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Flament, Camille, Michelle Salvia, Bruno Berthel, and Gerard Crosland. "Effect of Thermal Cycling on the Mechanical Properties of a Continuous Fibre Composite Used for Car Clutch Facings." Advanced Materials Research 891-892 (March 2014): 42–47. http://dx.doi.org/10.4028/www.scientific.net/amr.891-892.42.

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In dry clutch systems, the clutch facing is an annular shaped continuous fibre composite with organic matrix (thermo set resins) which transmits the torque from the engine to the wheels. In use it is submitted to thermo-mechanical cycling. Due to the composite fibre organisation, the strain field under thermo-mechanical loading is not homogenous. Full field data is needed to describe the material behaviour. Digital Image Stereo-Correlation (DISC) was used to determine the coefficient of thermal expansion (CTE) of the material. To determine the effect of temperature and cyclic loading on the mechanical properties, the composite was subjected to different thermal cycles. The material properties are modified with increasing temperature and number of cycles. These results were confirmed by dynamic mechanical analysis which showed thermal ageing of the resin. The local information given by the strain fields revealed a non uniform evolution of the material properties with thermal cycling.

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Behnke, R., M. Kaliske, and M. Klüppel. "THERMO-MECHANICAL ANALYSIS OF CYCLICALLY LOADED PARTICLE-REINFORCED ELASTOMER COMPONENTS: EXPERIMENT AND FINITE ELEMENT SIMULATION." Rubber Chemistry and Technology 89, no. 1 (March 1, 2016): 154–76. http://dx.doi.org/10.5254/rct.15.84852.

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ABSTRACT Elastomer components are often subjected to periodic loading conditions during service. Elastomer parts are used because of their large extensibility and significant damping characteristics, where the latter originate from inelastic material features. Combined with cyclic loading conditions, the inelastic properties of the material yield mechanical energy dissipation, its transformation to thermal energy, and heat buildup in the elastomer component. The experimental and numerical understanding of the thermo-mechanical coupling of elastomers is a prerequisite to predict the temperature rise in elastomer components. In this contribution, experimental and numerical investigations on cyclically loaded dumbbell-shaped elastomer components are addressed. A thermo-mechanical material model representing finite nonlinear viscoelasticity and a temperature- and deformation-dependent heat capacity is used within the finite element method to compute the heat buildup in the dumbbell-shaped elastomer components. The simulation results (surface temperature evolution) for three different loading frequencies are compared with experimental data.

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Liu, Yang, and Weizhe Wang. "Evolution of principal stress of a turbine rotor under cyclic thermo-mechanical loading." Engineering Failure Analysis 109 (January 2020): 104242. http://dx.doi.org/10.1016/j.engfailanal.2019.104242.

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Pasricha, Arun, Mark E. Tuttle, and Ashley F. Emery. "Time-dependent response of IM7/5260 composites subjected to cyclic thermo-mechanical loading." Composites Science and Technology 55, no. 1 (January 1995): 49–56. http://dx.doi.org/10.1016/0266-3538(95)00095-x.

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Pasricha, Arun, Mark E. Turtle, and Ashley F. Emery. "Time-dependent response of IM7/5260 composites subjected to cyclic thermo-mechanical loading." Composites Science and Technology 56, no. 1 (January 1996): 55–62. http://dx.doi.org/10.1016/0266-3538(95)00130-1.

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Blumenthal, A. v., E. Mahmoudi, K. Khaledi, D. König, and T. Schanz. "Innovative Concept for Analysing a Rock Salt Cavern under Cyclic Thermo-mechanical Loading." Energy Procedia 97 (November 2016): 478–85. http://dx.doi.org/10.1016/j.egypro.2016.10.054.

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Katori, Hiroaki, Masayuki Arai, and Kiyohiro Ito. "Comprehensive Numerical Simulation of Stress and Damage Fields under Thermo-Mechanical Loading for TBC-Coated Ni-Based Superalloy." Key Engineering Materials 774 (August 2018): 137–42. http://dx.doi.org/10.4028/www.scientific.net/kem.774.137.

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A finite element analysis code was developed to accurately predict stress and damage fields in thermal barrier coatings (TBCs) systems subjected to thermo-mechanical loadings. An inelastic constitutive equation for TBCs, and a Chaboche-type viscoplastic constitutive equation for Ni-based super alloys (IN738LC) were employed to simulate high temperature creep and cyclic deformation. Simulations of the TBC/IN738LC system subjected to two types of loading, namely, a triangle-wave loading and a GT-operation loading, were performed using the developed analysis code. The results confirmed that the stress and damage fields in the TBC/IN738LC system could be simulated accurately, and provided us with credible results regarding the crack occurrence. Additionally, the analysis under the GT-operation loading conditions revealed that a peak stress generated during the start-up operation would lead to delamination of the TBC, while a peak stress at the shut-down would lead to cracking in the substrate.

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Liu, Chang, and Wei Zheng Zhang. "Lifetime Prediction of Thermo-Mechanical Fatigue for Exhaust Manifold." Advanced Materials Research 433-440 (January 2012): 9–17. http://dx.doi.org/10.4028/www.scientific.net/amr.433-440.9.

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In this research, the non-linear thermo-mechanical simulation, experimental study and lifetime prediction of engine exhaust manifold were systematically analyzed. Fluid-structure coupled method was employed in the simulation. Heat transfer analysis simultaneous considered radiation, convection and conduction. Inelastic properties of the materials used for the thermo-mechanical analysis included kinematic hardening and creep. Some models were introduced and used to predict lifetime of the manifold. Temperature data obtained during the engine bench tests can be accurately matched with the analysis results. The results indicated that the highest temperature located on the confluence of exhaust manifold and the plastic dissipated energy field caused by the cyclic thermal loading can be matched with the crack zone of exhaust manifold.

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Rokbani, Maha, Luc Saint-Sulpice, Shabnam Arbab Chirani, and Tarak Bouraoui. "Fatigue properties by “self-heating” method: Application to orthodontic Ni-Ti wires after hydrogen charging." Journal of Intelligent Material Systems and Structures 29, no. 16 (May 31, 2018): 3242–53. http://dx.doi.org/10.1177/1045389x18778371.

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Ni-Ti superelastic alloys have been successfully used in orthodontic clinics thanks to their good biomechanical and biochemical behavior. However, during treatment, some orthodontic wires may break in the oral cavity. The susceptibility of these alloys to cyclic loadings and to hydrogen embrittlement is supposed to be main causes of these unexpected failures. This study presents a contribution to studying the effect of hydrogen, obtained after cathodically charging in 0.9% NaCl solution, on the fatigue behavior of Ni-Ti commercial orthodontic wires subjected to high-cycle fatigue. Fatigue tests were analyzed using self-heating method based on observing thermal effects under mechanical cyclic loading. The results obtained with self-heating approach imply that the increase in hydrogen charging time is connected with an increase in the mean stabilized temperature and a decrease in the fatigue life. Self-heating method allows a rapid prediction of the endurance limit with a good reproducibility of fatigue tests at high number of cycles. Furthermore, cyclic stress–induced transformations and conventional fatigue tests under strain control are considered in this work to investigate the effect of hydrogen on cyclic loading type and to acquire for a better understanding of the interaction between hydrogen and thermo-mechanical mechanisms in Ni-Ti alloys.

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Li, Dao-Hang, and De-Guang Shang. "Thermo-mechanical fatigue damage behavior for Ni-based superalloy under multiaxial loading." MATEC Web of Conferences 165 (2018): 19002. http://dx.doi.org/10.1051/matecconf/201816519002.

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The fatigue damage behavior was experimentally investigated in different axial-torsional thermo-mechanical loading conditions for Ni-based superalloy GH4169. The strain controlled tests were carried out with the same von Mises equivalent mechanical strain amplitude of 0.8% in the temperature range from 360°C to 650°C. The results show that the fatigue life is drastically reduced when the axial mechanical strain and the temperature are in-phase, which can be due to that the creep damage is induced by the tensile stress at high temperature. Moreover, the fatigue life is further decreased when the axial mechanical strain and the shear strain are out-of-phase, which can be attributed to that the non-proportional hardening can increase the creep and the oxidation damages. Furthermore, the tensile stress is crucial to the nucleation of creep cavities at high temperature compared with the shear stress. The tensile and shear stresses all can increase the creep damage under fatigue loading at high temperature. In addition, the oxidation damage can be induced during cyclic loading at high temperature, and it can be increased by the tensile mean stress caused in non-isothermal loading.

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Choi, Bok-Lok, and Hoon Chang. "Prediction of Thermal Fatigue Life of Engine Exhaust Manifold under Thermo-mechanical Cyclic Loading." Transactions of the Korean Society of Mechanical Engineers A 34, no. 7 (July 1, 2010): 911–17. http://dx.doi.org/10.3795/ksme-a.2010.34.7.911.

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Dhima, Dhionis, Maxime Audebert, and Abdelhamid Bouchaïr. "Analysis of the Thermo-Mechanical Behaviour of Steel-to-Timber Connections in Bending." Journal of Structural Fire Engineering 5, no. 2 (June 1, 2014): 97–112. http://dx.doi.org/10.1260/2040-2317.5.2.97.

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Two different configurations of steel-to-timber connections are tested in bending in normal conditions and under ISO-fire exposure. To observe the influence of clearances in the connection area on the fire resistance of the connections, two specimens were previously tested under cyclic loadings. These tests consist in the application of loading-unloading cycles by controlled displacements. The experimental results of connections tested in cold and under ISO-fire conditions are analyzed and commented. These results are then used to validate a finite element model. This model allows to simulate numerically the evolution of the temperatures inside the connections as well as their mechanical and thermo-mechanical behaviours. The thermal modelling is validated on the basis of the temperature-time evolutions measured during fire tests. The nonlinear modelling of the mechanical behaviour of timber is done using the Hill yield criterion in combination with the Tsaï-Wu failure criterion. The thermo-mechanical modelling allows obtaining fire resistances of the tested connections in good agreement with the experimental ones.

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Frenz, H., J. Meersmann, J. Ziebs, H. J. Kühn, R. Sievert, and J. Olschewski. "High-temperature behaviour of IN 738 LC under isothermal and thermo-mechanical cyclic loading." Materials Science and Engineering: A 230, no. 1-2 (July 1997): 49–57. http://dx.doi.org/10.1016/s0921-5093(97)00025-7.

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Konstantinov, V. M., and I. A. Buloichyk. "Influence of sherardizing on working properties of metal parts subjected to prior heat treatment." Litiyo i Metallurgiya (FOUNDRY PRODUCTION AND METALLURGY), no. 4 (December 16, 2020): 131–38. http://dx.doi.org/10.21122/1683-6065-2020-4-131-138.

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The article reveals the data concerning the mechanical properties changes of heat-treated steel articles subjected to thermo diffusion pack cementation. The temperature frames of thermo diffusion influence on tensile strength were determined for heat-treaded steel articles. Results of tensile test of high strength bolts treated using thermo diffusion pack cementation at 420 °C show no any effect from the side of pack cementation treatment on working properties of the tested samples. It is shown that in conditions of cyclic fatigue loading thermo diffusion pack cementation of heat treated article may leads to strength loss that can be explained by formation of solid intermetallic phases in a surface area of the article.

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Ganczarski, Artur, and Marcin Cegielski. "Thermal Effect Accompanying Low Cycle Fatigue of Al-2024." Solid State Phenomena 240 (August 2015): 108–13. http://dx.doi.org/10.4028/www.scientific.net/ssp.240.108.

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When a material is subjected to a cyclic loading at high values of stress or strain, both thermal and damage develop together with cyclic plastic strain. These processes are often accompanied by damage deactivation characterized by actual state of micro-cracks, which are generally active under tension and passive under compression. In classical formulation damage deactivation occurs instantly when loading changes sign and consequently leads to non-smooth path separating both load ranges. The real materials, however, do not exhibit such bilinear paths. Therefore, the more realistic model based on continuous damage deactivation is proposed, in which micro-cracks close gradually, see Cegielski and Ganczarski [2, 3, 4], Hansen and Schreyer [5]. Simultaneously, thermo-mechanical coupling may play essential role in processes of cyclic plasticity hence present formulation comprises an additional heat transfer equation.

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Raninger, Peter, Werner Ecker, Thomas Antretter, M. Leindl, and R. Ebner. "Interaction of Heat Checks in Aluminum Pressure Casting Dies and their Effect on Fatigue Life." Key Engineering Materials 488-489 (September 2011): 626–29. http://dx.doi.org/10.4028/www.scientific.net/kem.488-489.626.

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Pressure casting dies are exposed to harsh service conditions consisting of cyclic thermal and mechanical loading and thus undergo thermo-mechanical fatigue. Due to cyclic plastic deformation of the material near the surface of the dies the loading conditions gradually change because of the formation of tensile residual stresses which add to the stress field from external loading. This change in the stress field influences the nucleation and the growth of cracks. Typically after a few thousand casting cycles a network of heat checks forms. In such a network crack shielding has a big influence on the evolution of the crack array. Firstly, it influences the propagation rates of the cracks and secondly it may change the propagation direction compared to the case where no neighbors are present. The crack growth rate and the length at which the cracks stop growing are also influenced by the thermo-physical and mechanical properties of the die material. It was found that the shielding effects of neighboring cracks are of equal importance. Crack deflection caused by the presence of neighboring cracks can lead to break-outs at the surface ensued by fast degradation eventually necessitating the replacement of the die. Consequently, the focus in this work is put on the investigation of the interaction of cracks in a network and their effect on the fatigue life. The problem is tackled by means of an automated strategy based on the finite element method.

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Zhelyazov, Todor, Rajesh Rupakhety, and Simon Olafsson. "Mechanical and thermo-mechanical response of a lead-core bearing device subjected to different loading conditions." MATEC Web of Conferences 165 (2018): 16011. http://dx.doi.org/10.1051/matecconf/201816516011.

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The contribution is focused on the numerical modelling, simulation and analysis of a lead-core bearing device for passive seismic isolation. An accurate finite element model of a lead-core bearing device is presented. The model is designed to analyse both mechanical and thermo-mechanical responses of the seismic isolator to different loading conditions. Specifically, the mechanical behaviour in a typical identification test is simulated. The response of the lead-core bearing device to circular sinusoidal paths is analysed. The obtained shear displacement – shear force relationship is compared to experimental data found in literature sources. The hypothesis that heating of the lead-core during cyclic loading affects the degrading phenomena in the bearing device is taken into account. Constitutive laws are defined for each material: lead, rubber and steel. Both predefined constitutive laws (in the used general–purpose finite element code) and semi-analytical procedures aimed at a more accurate modelling of the constitutive relations are tested. The results obtained by finite element analysis are to be further used to calibrate a macroscopic model of the lead-core bearing device seen as a single-degree-of-freedom mechanical system.

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Nayebi, A., and M. Hamidpour. "Thermo-mechanical cyclic loading analysis of pipes with different type of defects: Temperature dependent properties." Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications 230, no. 1 (February 9, 2015): 303–10. http://dx.doi.org/10.1177/1464420715571432.

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Zhu, Yilin, and Leong Hien Poh. "On an energetic or dissipative isotropic hardening mechanism for thermo-mechanical models in cyclic loading." International Journal of Mechanical Sciences 122 (March 2017): 297–307. http://dx.doi.org/10.1016/j.ijmecsci.2017.01.022.

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Springer, M., A. Turon, and H. E. Pettermann. "A thermo–mechanical cyclic cohesive zone model for variable amplitude loading and mixed–mode behavior." International Journal of Solids and Structures 159 (March 2019): 257–71. http://dx.doi.org/10.1016/j.ijsolstr.2018.10.004.

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Behrens, B. A., A. Bouguecha, H. W. Raedt, and M. Sc T. Hadifi. "Numerical investigations on the fatigue failure of forging tools due to thermo-mechanical cyclic loading." International Journal of Material Forming 3, S1 (April 2010): 339–42. http://dx.doi.org/10.1007/s12289-010-0776-2.

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Rodinò, Stefano, Elio M. Curcio, Danilo A. Renzo, Emanuele Sgambitterra, Pietro Magarò, Franco Furgiuele, Marco Brandizzi, and Carmine Maletta. "Shape Memory Alloy—Polymer Composites: Static and Fatigue Pullout Strength under Thermo-Mechanical Loading." Materials 15, no. 9 (April 29, 2022): 3216. http://dx.doi.org/10.3390/ma15093216.

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This work was carried out within the context of an R&D project on morphable polymer matrix composites (PMC), actuated by shape memory alloys (SMA), to be used for active aerodynamic systems in automotives. Critical issues for SMA–polymer integration are analyzed that are mostly related to the limited strength of metal–polymer interfaces. To this aim, materials with suitable thermo-mechanical properties were first selected to avoid premature activation of SMA elements during polymer setting as well as to avoid polymer damage during thermal activation of SMAs. Nonstandard samples were manufactured for both static and fatigue pullout tests under thermo-mechanical loading, which are made of SMA wires embedded in cylindrical resin blocks. Fully coupled thermo-mechanical simulations, including a special constitutive model for SMAs, were also carried out to analyze the stress and temperature distribution in the SMA–polymer samples as obtained from the application of both mechanical loads and thermal activation of the SMA wires. The results highlighted the severe effects of SMA thermal activation on adhesion strength due to the large recovery forces and to the temperature increase at the metal–polymer interface. Samples exhibit a nominal pullout stress of around 940 MPa under static mechanical load, and a marked reduction to 280 MPa was captured under simultaneous application of thermal and mechanical loads. Furthermore, fatigue run-out of 5000 cycles was achieved, under the combination of thermal activation and mechanical loads, at a nominal stress of around 200 MPa. These results represent the main design limitations of SMA/PMC systems in terms of maximum allowable stresses during both static and cyclic actuation.

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Velay, Vincent, Denis Delagnes, and Gérard Bernhart. "Advances in Cyclic Behavior and Lifetime Modeling of Tempered Martensitic Steels Based on Microstructural Considerations." Key Engineering Materials 378-379 (March 2008): 81–100. http://dx.doi.org/10.4028/www.scientific.net/kem.378-379.81.

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Cyclic behavior and life prediction of two tempered martensitic steels (AISI H11 and L6) are investigated under thermo-mechanical loading conditions. Two non isothermal constitutive models developed in the same framework of the thermodynamics of irreversible processes are introduced. The first one, in relation with the tempering state, considers the fatigue-ageing phenomena whereas the second one is intended to take into account more complex loading paths. This last non unified approach allows to define different strain mechanisms which can be related to microstructural considerations. The strain-stress parameters provided by both approaches can be introduced into a lifetime model which is based on continuum damage mechanics.

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Karl, Justin O., Andrew T. Copeland, and Amy K. Besio. "A Phenomenological Predictive Model for Thermo-Mechanical Fatigue of Notched Type 304 Stainless Steel." Advanced Materials Research 1119 (July 2015): 838–43. http://dx.doi.org/10.4028/www.scientific.net/amr.1119.838.

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The behavior of parts subjected to simultaneous thermal and mechanical fatigue loads is an area of research that carries great significance in the power generation, petrochemical, and aerospace industries. Machinery with expensive components undergo varying applications of force while exposed to variable temperature working fluids. An example case is found in steam turbines, which subject stainless steel blades to cyclic loads from rotation as well as the passing of heated gases. Accurate service life prediction is especially challenging due to the thermo-mechanical loading being present on the complex geometric profile of the blades. This research puts forth a method for determining crack initiation lifetimes in variably-notched type 304 austenitic stainless steel specimens subjected to differing fatigue and thermo-mechanical fatigue conditions. A base analytical model and genetic algorithm were used to develop phenomenology-informed predictions that fall within a factor of two of the actual crack initiation times.

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Li, Dao-Hang, De-Guang Shang, Long Xue, Luo-Jin Li, Ling-Wan Wang, and Jin Cui. "Notch stress-strain estimation method based on pseudo stress correction under multiaxial thermo-mechanical cyclic loading." International Journal of Solids and Structures 199 (August 2020): 144–57. http://dx.doi.org/10.1016/j.ijsolstr.2020.04.002.

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Cho, Nak-Kyun, Haofeng Chen, James T. Boyle, and Fu-Zhen Xuan. "Enhanced fatigue damage under cyclic thermo-mechanical loading at high temperature by structural creep recovery mechanism." International Journal of Fatigue 113 (August 2018): 149–59. http://dx.doi.org/10.1016/j.ijfatigue.2018.04.014.

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Marinkovic, Dragan, Manfred Zehn, and Predrag Milic. "On the design of thermally loaded fiber optics feedthroughs." Thermal Science 20, suppl. 5 (2016): 1313–20. http://dx.doi.org/10.2298/tsci16s5313m.

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Thermo-mechanical design aspects of various structures exposed to cyclic thermal loading have a crucial impact on their lifetime. This is particularly valid for fiber optics feedthroughs that involve several materials with significantly different thermal expansion ratios. Thermal loading in such structures may give rise to non-trivial thermally induced deformations and therewith stresses, which can be adequately predicted and assessed only by a detailed 3-D numerical simulation. This paper considers a couple of design solutions of fiber optics feedthroughs, which have exhibited certain weaknesses in their application. Numerical simulation by means of the finite element method has been conducted to reveal the weak points of the design.

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Nguyen, Phuc, Andrei G. Kotousov, Sook Ying Ho, and Stuart Wildy. "Investigation of Thermo-Mechanical Properties of Slurry Based Thermal Barrier Coatings under Repeated Thermal Shock." Key Engineering Materials 417-418 (October 2009): 197–200. http://dx.doi.org/10.4028/www.scientific.net/kem.417-418.197.

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Thermal Barrier Coatings have existed for over 40 years, and with in the last 15 years their use in industrial applications has dramatically increased. Thermal Barrier Coatings (TBCs) are currently used in gas turbines, diesel engines, throughout aerospace and nuclear power industries. The purpose of TBC is to reduce temperature and thermal stresses, and, as a result, increase the reliability and life of load-bearing components subjected to high temperature or temperature flux. However, TBCs often fail under thermal cyclic loading with reliability still being the major issue impeding their wide-spread applications. The focus of this work is on experimental investigations of zirconia/nickel graded TBC system, subject to thermal shock loading. The graded TBC systems were fabricated utilising a recently developed slurry spray manufacturing technique. This is a robust technique, and is able to cover large and curved surfaces at low cost, and provides many advantages in comparison with its alternatives. This paper describes the developed technique and presents selected results of thermo-mechanical and fracture testing of the TBCs including graded coatings fabricated using this new technique.

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Niendorf, T., P. Krooß, C. Somsen, R. Rynko, A. Paulsen, E. Batyrshina, J. Frenzel, G. Eggeler, and H. J. Maier. "Cyclic degradation of titanium–tantalum high-temperature shape memory alloys — the role of dislocation activity and chemical decomposition." Functional Materials Letters 08, no. 06 (October 26, 2015): 1550062. http://dx.doi.org/10.1142/s1793604715500629.

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Titanium–tantalum shape memory alloys (SMAs) are promising candidates for actuator applications at elevated temperatures. They may even succeed in substituting ternary nickel–titanium high temperature SMAs, which are either extremely expensive or difficult to form. However, titanium–tantalum alloys show rapid functional and structural degradation under cyclic thermo-mechanical loading. The current work reveals that degradation is not only governed by the evolution of the ω-phase. Dislocation processes and chemical decomposition of the matrix at grain boundaries also play a major role.

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Grüning, Alexander, Markus Lebsanft, and Berthold Scholtes. "Residual Stress in Tools and Components in Case of Thermo-Mechanical Metal Forming Processes." Materials Science Forum 681 (March 2011): 340–45. http://dx.doi.org/10.4028/www.scientific.net/msf.681.340.

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Residual stresses play a key role in thermo-mechanically coupled forming processes for industrial mass production. They are an unavoidable consequence of the alternating inhomogeneous fields of temperature and mechanical stress developing in tools and components dependent on the process parameters applied. Because of their influence on the behavior of the components produced, a great interest exists to get reliable information about origin and distribution of the relevant residual stress fields and to understand the basic principles of their formation. In this paper the development of residual stress in tools (steel AISI H11) used for the thermo-mechanical forming operation of cylindrical flange shafts (steel SAE 6150) is outlined. The loading situation of the tool is simulated by thermal fatigue tests, providing information about cyclic stress and plastic deformation during the manufacturing process. Furthermore the residual stress states of the flange shafts manufactured are presented and discussed. Chip forming manufacturing operations are challenging tasks and tensile residual stresses can be avoided using adapted process parameters.

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Bhaumik, S. K., C. N. Saikrishna, K. V. Ramaiah, and M. A. Venkataswamy. "Understanding the Fatigue Behaviour of NiTiCu Shape Memory Alloy Wire Thermal Actuators." Key Engineering Materials 378-379 (March 2008): 301–16. http://dx.doi.org/10.4028/www.scientific.net/kem.378-379.301.

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This paper deals with the fatigue behaviour of NiTiCu shape memory alloy (SMA) wire actuators on thermo-mechanical cycling (TMC). Cyclic loading in SMA actuators is invariably associated with both functional and structural fatigue. The characteristic of the actuators such as austenite (hot shape) remnant deformation and recovery strain undergo changes upon TMC. These in turn result in continuous change in strain response (functional fatigue) during application. It has been shown that the functional fatigue can be minimized by adopting TMC at higher stress than that of the working stress prior to the application. On the other hand, failure of the actuators by fracture (structural fatigue) due to cyclic stress/strain is inevitable. Study shows that the fatigue life of the actuators is strongly dependent on the type of loading and the temperature range of operation. This has been explained in terms of damage accumulation, crack initiation and fracture behaviour.

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Journal articles on the topic 'Thermo-mechanical cyclic loading'

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