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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.

This article aims to present a new type of friction stir weld spindle system with 2 degrees of freedom. It explains the thermal–mechanical coupling mechanism between the welding tool and the workpiece, presents simulation of the heat distribution on a friction stir weld spindle under specific welding technology parameters, and provides the type selection and the reference design for temperature-sensitive components such as bearings and motor. The spindle system, which has high stiffness and excellent resistance to overload, is developed in accordance with the welding requirement for aluminum alloy products in the aeronautic and astronautic fields. The thermal–mechanical coupling model is established between the stir-pin and the workpiece. The heat generation and transfer processes are simulated, and the results of the temperature field distribution for the target position inside the spindle structure are obtained and verified by experiments. Test results show that the spindle system can meet the requirements of friction stir welding for large-scale complex surface structures. Simulation analysis has good consistency with experimental results, as proved by experimental verification. The resulting data can provide reliable reference design and type selection of temperature-sensitive components. Compared with other stir welding heads, this system has high stiffness and overload capacity, which can well meet the high-quality welding requirements of large-scale complex surface structures. Besides that, the thermal analytical method has universal applicability and can provide solutions for temperature field distribution of spindle under different workpiece materials and welding parameters. The friction stir weld spindle system is a novel design for welding large-scale complex surface structures. Its major advantages are the high stiffness and overload capacity. In addition, the heat and thermal simulation method, consisting of two stages, has provided the type-selection reference for the spindle design.

Flexure hinge mechanism plays a key part in realization of terminal nano-positioning. The performance of flexure hinge mechanism is determined by its positioning design. Based on the actual working conditions, its finite element model is built and calculated in ANSYS. Moreover, change trends of deformation and natural frequency with positioning design parameters are revealed. And sensitivity analysis is performed for exploration response to these parameters. These parameters are used to build four objective functions. To solve it conveniently, the multi-objective optimization problem is transferred to the form of single-objective function with constraints. An optimal mechanism is obtained by an optimization method combining ANSYS with MATLAB. Finite element numerical simulation has been carried out to demonstrate the superiority of the optimal flexure hinge mechanism, and the superiority can be further verified by experiment. Measurements and tests have been conducted at varying accelerations, velocities, and displacements, to quantify and characterize the amount of acceleration responses obtained from flexure hinge mechanism before and after optimization. Both time- and frequency-domain analyses of experimental data show that the optimal flexure hinge mechanism has superior effectiveness. It will provide a basic for realizing high acceleration and high precision positioning of macro–micro motion platform.

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.

The thermal-mechanical coupling effect is one of important factors in construction engineering, which will cause the buried thermal-pipeline to damage. So a three-dimensional finite element model is established based on ADINA-TMC, which considers thermal-mechanical coupling and seismic loading simultaneously. In this model, seismic loads and faults movement are defined. According to the numerical results, stresses and strains under gravity, seismic loading, and temperature load are compared, which provides theoretical method for failure analysis of buried thermal-pipeline.

ACB-CP is an auxiliary cold box used to distribute and control the cryogenic fluids to cool the cryopumps in ITER cryogenic system. A 3-D structure design is performed as a preliminary design. In order to validate the structure design, the thermal mechanical analysis on the piping must be followed. A 3-D finite element model of ACB-CP is built. The steady state thermal analysis and thermal mechanical coupling analysis of the internal piping are performed. The thermal stress distributions and the maximal thermal stress values are obtained. The results lay the reliable foundation for the design and improvement of ACB-CP.

A finite element model for analyzing the strain-stress field of laser cladding process was built and the process with powder feeding was analyzed with the model. Temperature variation during cladding described in Part I was applied as “body force” loads in the strain-stress analysis. The analysis result shows that, by the end of cladding, the clad layer is in tension stress and the stress values are varied in directions. The tension stress along the cladding direction is the maximum one, which causes the cracking in clayed layer. Increasing the preheating temperature of substrate is an effective way to avoid the crack generation.

Laser cladding consists of covering a substrate surface with a coating of a different nature. As a complex thermal-mechanical process, laser cladding is not quite understood yet. In this study, a finite element model for analyzing the temperature field was built and the laser cladding process with powder feeding was analyzed with the model. The analysis results show that the maximum temperature at the melting pool during cladding is directly proportional to the laser power and preheated temperature. The maximum cooling rate at the melting pool is inversely proportional to them. Increasing the preheated temperature can decrease the cooling rate of the clayed layer effectively. Increasing the laser power can also decrease the cooling rate, but the effect is not obvious.

The analysis model for the response of ceramic-metal FGMs under dynamic thermal loading is investigated. Emphasis is put on the effects of the residual stress, thermal- mechanical coupling and hardening model for the materials. It is shown that the three effects are significant when the materials’ response is inelastic and should carefully be considered in constructing the analysis model.