移动周期载荷作用下孔隙热弹性地基的动力学响应

根据孔隙热弹性线性理论,本文首先建立了在移动周期载荷作用下孔隙热弹性地基动力学响应分析的数学模型,其中提出了在周期性边界上必须满足的6类适当的条件,即界面位移相等、应力相等、孔隙百分比相等、温度相等以及在外法线方向孔隙发展相等和温度导数相等。在此基础上,分别采用微分求积法(DQM)和有限差分法(FDM)对控制方程进行空间和时间离散,并求解。作为算例,分别研究了在移动周期载荷和极限车载作用下孔隙热弹性地基的动力学响应,考察了车速对沉降、孔隙体积百分比和温度的影响。可以看到,本文提出的处理周期性问题DQM,具有精度高、收敛性好,计算效率高等特点。     

Propagation of plane waves at the imperfect boundary of elastic and electro-microstretch generalized thermoelastic solids

The problem of reflection and transmission of plane waves incident on the contact surface of an elastic solid and an electro-microstretch generalized thermoelastic solid is discussed. It is found that there exist five reflected waves, i.e., longitudinal displacement （LD） wave, thermal （T） wave, longitudinal microstretch （LM） wave and two coupled transverse displacement and microrotational （CD（I） and CD（II）） waves in the electro-microstretch generalized thermoelastic solid, and two transmitted waves, i.e., longitudinal （P） and transverse （SV） waves in the elastic solid. The amplitude ratios of different reflected and transmitted waves are obtained for an imperfect boundary and deduced for normal force stiffness, transverse force stiffness, and perfect bonding. The variations of amplitude ratios with incidence angles have been depicted graphically for the LD wave and the CD（I） wave. It is noticed that the amplitude ratios of reflected and transmitted waves are affected by the stiffness, electric field, stretch, and thermal properties of the media. Some particular interest cases have been deduced from the present investigations.     

Effect of relaxation times on circular crested waves in thermoelastic diffusive plate

The propagation of circularly crested thermoelastic diffusive waves in an infinite homogeneous transversely isotropic plate subjected to stress free, isothermal/insulated and chemical potential conditions is investigated in the framework of different thermo- elastic diffusion theories. The dispersion equations of thermoelastic diffusive Lamb type waves are derived. Some special cases of the dispersion equations are also deduced.     

Propagation of Rayleigh waves on free surface of transversely isotropic generalized thermoelastic diffusion

The present paper is devoted to the study of Rayleigh wave propagation in a homogeneous, transversely isotropic, thermoelastic diffusive half-space, subject to stress free, thermally insulated/isothermal, and chemical potential boundary conditions in the context of the generalized thermoelastic diffusion theory. The Green-Lindsay（GL） theory is used in the study. In this theory, thermodiffusion and thermodiffusion mechanical relaxations are governed by four different time constants. Secular equations for surface wave propagation in the considered media are derived. Anisotropy and diffusion effects on the phase velocity, attenuation coefficient are graphically presented in order to present the analytical results and make comparison. Some special cases of frequency equations are derived from the present investigation.     

A new boundary element method for the solution of plane steady-state thermoelastic fracture mechanics problems

An efficient numerical technique is developed for plane, homogeneous, isotropic, steady-state thermoelasticity problems involving arbitrary internal smooth and/or kinkedcracks. The thermal stress intensity factors and relative crack surface displacements due to steady-state temperature distributions are determined and compared to available solutions obtained by other methods. In these analyses the thermal boundary conditions across the crack surface are assumed to be insulated. The present approach involves coupling the direct boundary integral equations to newly developed crack integral equations.     

Metastable effects on martensitic transformation in SMA

The Clausius-Clapeyron coefficient (CCC or α_CC) or relation of the stress to transform a thermoelastic SMA sample and temperature, is revisited for 1-dimensional stressed SMA when polycrystalline materials are used. The experimental method is discussed in the frame of equilibrium thermodynamics for polycrystalline materials. Suggestions for evaluation of the experimental value in polycrystalline NiTi and CuAlBe specimens are proposed. The analysis for NiTi wire gives a CCC of α_CC=6.3±0.3 MPa K⁻¹. On the other hand CuAlBe provides a value of α_CC=2.2±0.4 MPa K⁻¹ for tensile stress.     

在重力作用下的上覆无限热弹性流体对广义热弹性固体转动的影响

计及上覆无限热弹性流体的重力作用,沿界面有不同的外力作用时,研究广义热弹性固体的旋转变形问题.在Laplace和Fourier域内,通过积分变换,得到了位移、应力及温度分布的表达式.然后在物理域内,应用数值逆变换方法,得到这些分量的值,并讨论了该问题的一些特例.结果以图形方式给出,显示了介质的旋转以及重力作用的影响.     

两点边值条件热弹性收缩模型的线性稳定性

1Introduction Theanalysisofthermalcontactproblemshasrevealeawealthofinteresting phenomena.BeginningwithJ.R.Barberin1978[1],whopointedoutthatthesolutionof suchproblemsposescertaindifficulties,andcontinuingtothisday,numerousresearchers haveturnedtheirattent…