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Thermal deformation caused by temperature rise affects the contact status of bearings in motorized spindles. In turn, the change in the contact status will affect the temperature rise and thermal deformation of the system. However, the latter has been rarely focused on in the previous literature. Therefore, a thermal network model of motorized spindle is enhanced by considering the thermal–mechanical coupling effect. Then, an iterative method is presented to solve the coupled equations, and a temperature test rig of the motorized spindle is set up to verify the proposed model. The predicted results by the proposed model are compared with the experimental results and the predicted results by the previous model. The relative error between the predicted and experimental results at two test points decreases by 9.56% and 3.44%, respectively, after considering the thermal–mechanical coupling effect. The temperature changes the contact angle and contact load of the bearings, thereby causing changes in frictional heat and temperature field. Such changes cause the difference between the proposed and previous models. The comparison with the experimental results shows that the proposed model with thermal–mechanical coupling effect can obtain a more accurate temperature field than the previous model.

In this paper, finite-element analysis (FEA) is carried out on the temperature field and stress field of automobile engine piston, as well as the thermal-mechanical load coupling stress field. Through the analysis, the authors grasped the thermal load and combined stress distribution of the piston, and thus optimized the piston design to improve its operational reliability. Specifically, a 1/4 solid model of the piston was constructed in the three-dimensional (3D) computer-aided design (CAD) software Pro/ENGINEER, and then converted into a finite-element model in Pro/Mechanica. Then, an alternating load was imposed on the piston model, and fatigue analysis was performed to identify the parts of the piston prone to fatigue failure, and judge whether the piston structure satisfies working requirements. Next, temperature field analysis was carried out on the piston model. The distribution of the steady-state temperature field as determined by applying temperatures and heat transfer coefficients as required by the boundary conditions of the third kind. Finally, the piston model was subject to thermal-mechanical coupling analysis. The stress and deformation distributions of the piston under the coupled stress field were ascertained under the boundary conditions of temperature field distribution and mechanical load. Through the above work, the authors obtained the basis for safety evaluation of piston, laying the foundation for further reducing the thermal load and optimizing the stress distribution of piston.

A nonlinear analysis on the thermal-mechanical coupling bending behavior of functionally graded porous curved micro-tubes is performed in this research. The case of curved micro-tubes with doubly-c...

As the depth of coal mining continues to increase, the weight of the overlying strata and the ground stress on the residual coal in goaves also increase. At the same time, the temperature of the co...

In view of the structural stability problem of different typical stiffened panels under different loading conditions, ABAQUS software was used to build finite element models of four typical stiffened panels with the same cross section area. The buckling and post-buckling response of the stiffened panels was analyzed and buckling modes and deflection curves of stiffened panels under mechanical, temperature and thermal-mechanical coupling load were obtained. The result indicates that T type stiffened plate shows great stability under mechanical load, the maximum load is 281KN, which is much higher than that of other types of stiffened panels. The maximum load of a stiffened panel is little affected by the direction of the fillet, but reasonable layout of panels can greatly reduce the out-of-plane displacement of the stiffened panel. There is no obvious pre-buckling process when a panel is under thermal-mechanical coupling load and the post-buckling response is roughly similar as that under mechanical load. But the maximum load of a stiffened plate will decrease by 8%-15% due to the application of temperature load.

In this study, the creep properties of cylindrical metal rubber (MR) specimen under static compression at elevated temperatures were investigated by a series of creep experiments. The cylindrical MR specimen has a good symmetrical property, and the mechanical properties are consistent in its different axial section. The failure determination parameters of MR under the coupling of thermal and mechanical static load of the forming direction were proposed in four aspects: the overall height, the average stiffness, the energy dissipation, and the variation of the loss factor. The variation patterns of the properties of the MR specimens were investigated with a static load at different temperatures for 324 h. The analytical equipment, including the simultaneous thermal analyzer (TGA/DSC), X-ray diffractometer (XRD), and scanning electron microscope (SEM), were used for material characterization and failure analysis. Based on the results, it is found that there are significant differences in the MR property variations subjected to creep tests at different elevated temperatures. The results indicated that an appropriate heat treatment for MR specimens would improve the creep resistance at elevated temperatures. In addition, the overall height and energy dissipation of the MR specimens were increased, and the average stiffness and the loss factor were decreased under the creep tests at 200 °C and 250 °C. However, under the creep tests at 25 °C, 300 °C, 350 °C, and 400 °C, the overall height, the energy dissipation and the loss factor were decreased, but the average stiffness was increased.

Space fission power systems can enable ambitious solar-system and deep-space science missions. The heat pipe-cooled reactor is one of the most potential candidates for near-term space power supply, featuring safety, simplicity, reliability, and modularity. Heat pipe-cooled reactors are solid-state and high-temperature (up to 1500 K) reactors, where the thermal expansion is remarkable and the mechanical response significantly influences the neutronics and thermal analyses. Due to the considerable difference between heat pipe-cooled reactors and traditional water reactors in the structure and design concept, the coupling solutions for light water reactors cannot be directly applied to heat pipe-cooled reactor analyses. Therefore, a new coupling framework and program need to consider the coupling effects among neutronics, heat transfer, and mechanics. Based on the Monte Carlo program rmc and commercial finite element program ansysmechanicalansys parametric design language (APDL), this work introduces the three coupling fields of neutronics (N), thermal (T), and mechanics (M) for heat pipe cooled reactors. Besides, the finite element method and the Monte Carlo program use different meshes and geometry construction methods. Therefore, the spatial mapping and geometry reconstruction are also essential for the N/T-M coupling, which is discussed and established in detail. Furthermore, the N/T-M coupling methods are applied to the preliminary self-designed 10 kWel space heat pipe cooled reactor. Coupling shows that the thermal-mechanical feedback in the solid-state reactor has negative reactivity feedback (about −2000 pcm) while it has a deterioration in heat transfer due to the expansion in the gas gap.

M3 fuel which microencapsulated TRISO particles in zirconium metal matrix is an integrated fuel designed to replace the traditional pellet-cladding fuel rod. The fuel design can effectively solve the problems of LWR fuel, such as water side corrosion, abrasion, pellet-cladding interaction, stress corrosion cracking and internal pressure bracing. Because of the multiple coating structure of TRISO particles and complex contacting behavior and deformation between TRISO particle and metal matrix, M3 fuel exhibits complex in-pile behavior. In order to establish the simulation method for the M3 fuel, the three-dimensional model was established by using ABAQUS software. The complex contacting behavior and deformation of coated layers and matrix for M3 fuel was considered. The results indicated that bonded strength between TRISO particle and Zr matrix has great effect on the stress distribution of SiC layer and matrix. The vulnerable area of Zr matrix located in the nearest position of TRISO particle to TRISO particle. The maximum tensile hoop stress of SiC layer was up to 150 MPa under strong bonding state, while SiC layer suffered compressive stress during all operation time for the weak bonding state. The failure probability of SiC layer was about 7 × 10−3 under strong bonding state which much higher than the weak ones. Thus, the integrity of SiC layer can be maintained by controlling the bonding strength between TRISO particle and Zr matrix during manufacturing process.

As the CNC machine tool feed mechanism is affected by joint action of heat and load during the working process, thermal–mechanical coupling analysis and experimental research on CNC machine tool feed mechanism are conducted. On the basis of exploring the thermal–mechanical coupling effect of CNC machine tool feed mechanism, a thermal–mechanical coupling dynamic analysis method is proposed through combining multi-step finite element simulation with temperature field experiment. According to the proposed method, the transient and steady-state simulation analysis on CNC machine tool feed mechanism are conducted and conclusions obtained are as follows, before the whole feed mechanism reaches thermal balance state, the thermal–mechanical coupling effect makes the deformation of the feed mechanism increase with the temperature rising. The correctness of the proposed thermal–mechanical coupling dynamic analysis method was verified by the contrastive analysis of the experiments. Therefore, in the process of CNC machine tool feed mechanism’s analysis and design, the influence of thermal–mechanical coupling effect on dynamic performance should be considered.

Inserts supporting run-flat tire is a key technology in the field of vehicle active safety. When the vehicle is under zero driving condition, the deformation of the inserts supporting run-flat tire due to compression can cause the tire to be crushed, and loss of adhesion between the tire and rim can lead to separation. These situations can reduce the cruising ability of the vehicle. Under zero driving condition, the insert, which is the main support body for the tire, could rub against the inner part of the tire sharply, thereby generating heat in the tire. Heat in the tire is difficult to dissipate and can accumulate rapidly under this condition. As the temperature of the tire and insert increases, the inserts supporting run-flat tire could fail to support the vehicle. To improve heat dissipation of the insert, a finite element model of the inserts supporting run-flat tire under the condition of zero rolling is established. The steady-state temperature field of the inserts supporting run-flat tire is analyzed using ANSYS Workbench. The insert temperature field and heat flux are solved. The optimization design of axial heat dissipation holes and surface heat dissipation grooves based on experimental and simulation results of the insert is presented. Finally, the optimization structure of the insert is verified using a thermal–mechanical coupling simulation method. The conclusions are of great significance for optimizing inserts supporting run-flat tire and improving zero rolling ability of tire.

An analysis model of casing stress distribution and its variation regularities presents several challenges during hydraulic fracturing of shale gas wells. In this paper, an analytical mechanical - thermal coupling method was provided to evaluate casing stress. In the model, the casing, cement sheath, and formation (CCF) system was divided into four stress field induced by uniform stress, deviator stress, shear stress, and thermal stress,. Based on this analytical model, the parametric sensitivity analyses of casing stress such as mechanical properties, operation parameters, and geo-stress were conducted during multi-fracturing. The results indicated the casing stress increased first, then decreased with the increase of cement sheath modulus. However, it always decreased with the increase of cement sheath Poisson's ratio and the injection fluid temperature. The casing stress increased dramatically with the increase of δ. However, it decreased first, then increased with the increase of fracturing pressure. Higher fluid temperature, cement with small modulus and large Poisson’s ratio were effective to decrease the casing stress. In conclusion, the analytical model can accurately predict casing stress and become an alternative method of casing integrity evaluation for shale gas wells. It is a useful and efficient method for a preliminary design, being capable of simulation the actual situations in order to assess the casing stresses and integrity.

Space fission power systems can enable ambitious solar-system and deep-space science missions. The heat pipe cooled reactor is one of the most potential candidates for near-term space power supply, featured with safety, simplicity, reliability, and modularity. Heat pipe cooled reactors are solid-state and high temperature (up to 1500 K) reactors, where the thermal expansion is remarkable and the mechanical response significantly influences the neutronics and thermal analyses. Due to the considerable difference between heat pipe cooled reactors and traditional water reactors in the structure and design concept, the coupling solutions for light water reactors cannot be directly applied to heat pipe cooled reactor analyses. Therefore, new coupling framework and program need to consider the coupling effects among neutronics, heat transfer as well as mechanics. Based on the Monte Carlo program RMC and commercial finite element program ANSYS Mechanical APDL, this work introduces the three coupling fields of neutronics (N), thermal (T), and mechanics (M) for heat pipe cooled reactors. The neutronic and thermal-mechanical (N/T-M) coupling strategy is developed theoretically, focusing on the formulation of the nonlinear problem, iteration schemes, and relaxation methods. Besides, the finite element method and the Monte Carlo program use different meshes and geometry construction methods. The spatial mapping and geometry reconstruction are also essential for the N/T-M coupling, which is discussed and established in detail. Furthermore, the N/T-M coupling methods are applied to the preliminary self-designed 10 kWe space heat pipe cooled reactor. Coupling shows that the thermal-mechanical feedback in the solid-state reactor has negative reactivity feedback (−2007 pcm) while it has a deterioration in heat transfer due to the expansion in the gas gap.

The Emergency Core Cooling System (ECCS) is actuated following Loss of Coolant Accidents (LOCA) to inject coolant into the primary loop through a 45° T junction configuration in advanced nuclear power plants. The T junction would suffer high cycle thermal fatigue due to possible temperature fluctuations in a non-isothermal mixing cross section. In this paper, the feasibility of Computational Fluid Dynamics (CFD) method on the complex mixing phenomenon simulation in a 45° T junction during the injecting process was verified against experimental data. The thermal mixing mechanism of different injection patterns, which was characterized by the MR number, was unveiled. Moreover, the structure stress analysis was performed to investigate the stress distribution features utilizing thermal-mechanical coupling method. The flow patterns of impact jet flow, deflection flow and upper wall jet flow were defined. The structure stresses were concentrated at the junction joint zone under all the three flow patterns. The variations of maximum stress with MR number were achieved. This work provides a guideline of CFD method for the mixing process simulation in a 45° T junction of ECCS and an important basis for the fatigue assessment and safety management in nuclear power plants.

With the rapid development of urban rail transit and the increasing level of research and development, aluminum alloy materials feature excellent physical and mechanical properties, and thus an urban rail transit vehicle adopts aluminum alloy materials. Friction Stir Welding (FSW) technology is adopted in the production process of a bolster in this article and research of stress strain of friction stir welding parts plays an important role for engineering application of friction stir welding technology.

In this paper, the theory of process failure as the basis for analysis of working conditions based on the use of production line process equipment. In ANSYS static strength theory, technology and equipment to analyze the static strength, find the weak points of equipment. For weak points and system reliability and lifetime prediction, and establish the reliability of the system platform to guide the process equipment and tooling security monitoring, to provide a scientific basis for the use of tooling and equipment reliability.

PFC-GBM (Particle Flow Code-Grain Based Model) is the major and fundamental method to simulate rock behaviors in this paper. Geo-materials are composed of micro-grains, the behavior of these grains and the interface between them influence macroscopic behavior of materials. Traditional PFC simulation method could simulate the integral micro-behavior of material, and PFC-GBM simulation focuses on every different grains and interfaces to simulate micro-heterogeneity of material. In this paper, an attempt is made to investigate the strength of rock masses and the development of micro-cracks under thermal-mechanical coupling effect. For this purpose, a numerical model is established based on mineral analysis and pre-existing mechanical experiments of Granite from one of complex tunnels in Yunnan Province. After establishing the model, the specimen were first heated and then compressed according to test sequence of laboratory experiments. The simulation results are calibrated to match the laboratory test results including thermal behaviors and fracture development. The conclusion of simulations show that both of thermal behaviors and fracture development are depended on the micro-heterogeneity of granite in UCS (Unconfined Compressive Strength) experiment, the characteristics of minerals influence the macroscopic fracture mechanism. The simulation reveals that in a certain range of temperature (40°C ~ 90°C), temperature increasing enhance the brittle damage of granite. The situation of 130°C had the obvious thermal-crack before loading and then exhibited a much lower peak strength and failure strain. This numerical observation may guide the underground construction in complex geo-environment.

In this paper, the thermal mechanical coupling problem of an infinite two-dimensional decagonal quasicrystal matrix containing elastic elliptic inclusion is studied under remote uniform loading and...

This paper develops a non-probabilistic system reliability-based design optimization method for composite laminated structures under mechanical - thermal coupling environments. This method improves the traditional method of roughly considering the temperature effect through the humid-thermal amplification factor and precisely considers the thermal stress and temperature effects. In addition, a system reliability analysis method and structural failure criterion for composite laminated structures based on the theory of last-ply failure (LPF) are proposed. The method can calculate the system reliability of composite laminated structures by considering the correlation of multiple failure modes. Finally, non-probabilistic system reliability-based design optimization (NSRBDO) of composite laminated structure system in a thermal–mechanical coupling environment is completed by means of the two-level optimization method. After the proposed optimization strategy is described in detail, two examples of the laminated structure are illustrated, and the results are compared to the traditional design method using the humid-thermal amplification factor, demonstrating the advantages and validity of the proposed method.

In order to study the rock thermal cracking law of the roof rock in the combustion zone of underground coal gasification under the special condition of unidirectional heating, the PFC particle flow software was used to carry out the numerical simulation of thermal-mechanical coupling. The uniaxial compression experiment was used to complete the PFC parameter calibration, establish a mechanical model, and compare the results of the unidirectional heating test with the simulation results. It was found that the relationship between the temperature at the measuring point, the thermal stress and the heating time of the two is very similar. It shows that the simulation results are highly accurate. The simulation results are as follows: when the model is at 450°C and 600°C, larger-scale cracks are formed and the second larger-scale crack evolution occurs; acoustic emission simulation can be divided into three stages: the first peak stage, the energy accumulation stage, and the second stage. In the second peak stage; the number of model cracks increases with the increase in temperature, and the shear cracks are the main ones, indicating that the model will expand laterally after being subjected to thermal stress, mainly occurring shear failure.

This paper takes automobile disc brakes as the research object, and designs a novel magnetostrictive disc actuator based on the characteristics of large output force, high displacement resolution and fast response speed of giant magnetostrictive material. Based on the vehicle parameters of a new energy vehicle as the design basis, calculate the specific structure and size of the magnetostrictive actuator, and use CATIA software to complete the system parametric modeling, import the built model into COMSOL Multipysics. The simulation results show that the output displacement and output force of the actuator can meet the requirements of braking, and the maximum temperature of the surface of the friction pair is far from the temperature limit of the brake, the rationality of the design and the correctness of the simulation model are verified.

In this study, according to the structure and material characteristics of the metal-matrix dispersed plate-type fuel assembly, a series of mathematical and physical models were established, including thermal-hydraulic analysis, stress-strain calculation, bending and torsion calculation and other auxiliary models. Based on these models, a thermal-mechanical coupling analysis scheme was designed and a fuel behavior analysis code FROBA-PLATEs was independently developed. The accuracy and reliability of the code FROBA-PLATEs was validated by the single-module validation method. The validated code was used to perform the thermal-mechanical behavior simulation of a hypothetical metal-matrix dispersed plate-type fuel assembly. Significant parameters, such as flow distribution, temperature profile and stress-strain profile, were obtained. In addition, some important thermal-mechanical phenomena, including the asymmetric heat transfer of the edge plate, the bending of side panel of and the torsion of the whole assembly, were simulated and evaluated.

To realize the active phased array radar antenna BGA encapsulation reliability assessment, A BGA solder joint finite element model is set up, which is based on PCB and HTCC substrate. Combining the creep properties of solder simulated by uniform Anand model, solder joints under temperature cycling stress distribution is studied, and the Coffin-Manson model is used for calculating the solder joint fatigue life by the whole model and organic union method from sub-model. The results show that the thermal stress of the solder ball on the side close to the HTCC while far away from the packaging structure center is the highest, and the fatigue failure happens after 192.3 cycles, which is basically consistent with the experimental results.

Taking the rear wheel brake of a certain brand of sightseeing vehicle as an example, floating caliper disc brakes and leading trailing shoe brake were simulated and compared for determining rear wheel brake types. The simplified model is established by UG software, imported into Workbench for thermal-mechanical coupling analysis under 10 braking conditions. The results show that the two brakes can meet the requirements of the vehicle, the former has better performance, and the latter has lower cost.

The geological environment along a buried pipeline in permafrost regions is complex, where differential frost heave often occurs. To understand the changes in the stress behavior of pipeline structures caused by corrosion while laying them in permafrost regions, we established a thermo-mechanical coupling model of buried pipeline with corrosion defects by using finite element software. Numerical simulation analysis of buried pipeline was conducted. The effects of the frost heave length, the length of the transition section, the corrosion depth, and the corrosion length on the stress displacement were obtained. These analyses showed that the stresses and displacements of the pipeline with corrosion defects in permafrost regions can be simulated by using the finite element software numerical simulation method. Afterward, the corrosion resistances of pipelines with different corrosion lengths and depths were investigated via an electrochemical testing method. These results can provide some useful insights into the possible mechanical state of buried pipeline with regard to their design and construction, as well as some useful theoretical references for simulating real-time monitoring and safety analysis for their operation in permafrost regions.

本文提出在制动盘热机耦合分析时考虑安全余量，以200 km/h高速列车为例，设计了4种安全余量仿真方案，分析两次紧急制动工况下制动盘温度场和应力场，结果表明增加减速度方案的计算安全系数最高，增加速度方案的计算安全系数最低，增加轴重方案和降低制动盘许用范围方案居中。 An innovative idea of taking consideration of safety margin during disc thermal-mechanical coupling analysis was proposed. One high speed train at 200 km/h as research model was taken for 4 different working conditions about safety margin in simulation. It aimed to analyze simulation results of temperature field and thermal stress field of braking disc after twice urgent braking. The outcomes obtained showed that the calculated safety factor would be the biggest under “de-celeration” condition, while the “acceleration” condition results in the smallest factor. Two other suppositions of “addition of axle load” and “reduction of allowable disc area” are mediate.

The thermal expansion phenomenon of bearings happening on a motorized spindle has a great effect on its dynamical properties. Hence, there is a vital need to analyze the relationship between its cooling condition and dynamical behaviors for the system. A thermal–mechanical coupling model of a motorized spindle system is presented in this article, which consists of three coupling sub-models: bearing, thermal and spindle dynamical model. The bearings, taking the thermal expansion into count, provide the shaft with support stiffness which influences the spindle dynamical properties. And their power loss is one of the main heat sources of the system while the other one is from the motor. In the thermal model, the cooling condition and heat generation jointly determine the temperature rise and thermal expansion. Thus, all of the sub-models interact and the system becomes an integrated thermal–mechanical coupling model. The proposed model is investigated by a solution procedure and validated experimentally. And the effects of the rotational speed, cooling water flow rate and oil-air pressure on the spindle dynamical properties are provided by this mathematical model as well as the experiments. The good agreement of results from them indicates that this model is capable of predicting the dynamical properties of the motorized spindle system. Then some feasible methods to improve the dynamical behaviors of the system are obtained.

In order to reveal the influence of thermal on the stress distribution of fiber wrapped high-pressure hydrogen vessel, the strain and stress of the vessel in pure mechanical loads are studied firstly. Then thermal loads are taken into account, and the thermal stress distribution is given out. The results show that, the stress of the vessel liner changes little when the loads differ from pure mechanical loads to thermal mechanical coupling loads. While in the fiber-wrapped layer, stresses change significantly, and are non-monotonic. In addition, the deformation of the vessel decreases under thermal mechanical coupling loads.

In order to increase rolling efficiency and production quality, adopted the finite element method, the rolling force analysis model of 3500mm rolling mill is established in this paper based on the thermal mechanical analysis theory, According to the rolling technology parameters in actual production, the rolling process of plate rolling is systematic studied, which thinks about the thermal stress caused by uneven temperature distribution. The law of technology parameters influencing rolling force is gained, which uses in the optimization of rolling process, improves production efficiency. it has important significance to reduce the energy consumption.

In order to effectively improve the calculation accuracy of finishing rolling force model for hot rolling wide and heavy stainless steel clad sheets, based on the E.Orowan unit pressure equilibrium differential equations and R.B.Sims unit pressure formulas, this paper divides hot-rolled composite deformation area into I, II two zones according to rolling stock jamming experiment, and then derives the finishing rolling force calculation formulas. Finally, by ANSYS/LS-DYNA thermal mechanical coupling simulation and experiment, the results show that compared with measured values, the relative error of simulated values is about 20%, the relative error of calculated values is less than 10%. Therefore, the rolling force model can accurately predict the size of rolling force and effectively improve the calculation accuracy of rolling force.

The fatigue failure mode of the brake disc is the initiation and expansion of the fatigue crack on the surface of the brake disc until the brake disc brakes. Therefore, considering the fatigue failure mode of the brake disc, the fatigue life of the brake disc is calculated. Firstly, the thermo-mechanical coupling model of the brake disc and pad is established by Abaqus software, so that temperature and stress of the brake disc could be obtained. Then, the surface crack initiation life of the brake disc is calculated by fe-safe software Finally, the fatigue crack growth life of the brake disc is calculated by nCode software. The calculation and analysis results show that the fatigue crack of the brake disc appears on the outer side of the brake disc friction surface under the working condition of this paper. The crack initiation life is that the number of braking is 12830 and the crack propagation life is 695000for the number of braking.

Functionally graded materials is a new material for thermal protection in the aerospace field. It is extremely important to study the temperature and stress changes in the thermal environment to ensure the normal operation of the spacecraft and the safety of crews. In this paper, ABAQUS is used to perform sequential thermal coupling and full thermal coupling analysis. The temperature variation and mechanical properties of functionally graded cylindrical shells in thermal environment under temperature and force field and temperature field interacts with force field are studied. Based on the first law of thermoelasticity and thermodynamics, the three-dimensional stress and energy equations of functionally graded cylindrical shells in thermal environment are derived. The example shows that the temperature variation law and mechanical characteristics of the two types of thermo-mechanical coupling analysis are almost the same. The temperature value results of the sequential thermal-mechanical coupling analysis are the same as the results of the full thermal coupling, but the stress value results are lower than the results of the full thermal coupling.

The fire has brought great harm to human, so it is of vital significance to establish a scientific method of structural fire resistance design to avoid personnel casualties and economic loss in the destroy or collapse of the structure in fire. The mechanical properties of materials deteriorate at the high temperature of the fire, and the structure can be damaged easily, so the damage cumulative impact must be considered in the structural resistance capability to fire. Damage mechanics is a powerful tool in the study of structural damage and destroy. In the paper, the damage mechanics is introduced into the calculation of resistance capability to fire of concrete structure, and the thermal-damage analysis of concrete member is achieved through the second development on ANSYS platform by using the residual strength thermal-damage model at high temperature.

In steam injection wells, the temperature of heat steam is very high and casing is heated during steam injection process, which has become the main reason of casing damage. Therefore, finite element model is very important to analyze the thermal mechanical coupling and casing damage in steam injection wells. Three-dimensional finite element model is investigated; geometry model is constructed with native and parasolid method in ADINA. The casing is modeled by native method and strata are modeled by parasolid method, casing is subtracted and merged with strata by Boolean Operation. Comprehensive loads are defined in structure model, and temperature load in thermal model. In thermal model, all materials are treated as heat conduction material. Thermal-mechanical coupling and casing damage are calculated with finite element model of thermal-mechanical coupling. According to the calculating results, the mechanism of casing damage is analyzed. Finally, some advice is proposed to the protection of casing in steam injection wells.

This paper aims to the physical characteristics of rock mass in the course of rising from room temperature to 600C. The maximum stress is reduced from 29.95MPa to 15.65MPa when the temperature rises above 400 degrees, the modulus of elasticity decreased by even more than 90% between 250 and 400C. The rock Poisson ratio is gradually increasing when the temperature rises from 30 to 100C, the Poisson's ratio decreases sharply with the temperature rising from 100 to 300C.

Based on rolling technology of stretch reducing mill group, by using large-scale general-purpose finite element analysis software ANSYS/LS-DYNA, a 3D thermal mechanical coupled numerical calculation of stretch reducing process, stress field, strain field, temperature field and the distribution of wall thickness were obtained, as well as the distribution of asymmetrical metal deformation when pipe passing every mill. The results of numerical simulation provide a reasonable cause for uneven wall thickness distribution, guiding the design of stretch reducing process.