Anisotropic Thermoelastic Materials Research Articles

Thermal-stress assessment of double-layer thermoelastic coatings based on Green’s function

Using the potential function and the mirror method, three-dimensional (3D) Green’s function solutions of double-layer coating structures with arbitrary thickness for anisotropic thermoelastic materials were obtained. The exact 3D explicit closed analytical forms of the temperature and thermal-stress fields were expressed by simple functions. This form can be used to accurately calculate the full field distribution under a heat source load, particularly for ultrathin coating structures. Numerical results indicated that the coating thermal parameters, coating stiffness, and coating thickness significantly affected the temperature and stress field. The influence rules of key parameters obtained in this study can guide the design of double-layer coating structures for thermal environments.

Nonlinear generalized thermoelasticity: theory and application

In this work, the hypothesis of nonlinear thermoelasticity has been arranged for anisotropic thermoelastic materials to analyze the thermal effect caused by mechanical deformation. The stress–strain equation to be nonlinear form is more important than the non-linearity in the geometrical structure. A common and fundamental formalization of the energy equilibrium to enclose the execution has been revolved. The governing equations of the nonlinear thermoelasticity model with one relaxation time have been constructed and solved for an isotropic one-dimensional thermoelastic and homogeneous half-space. This new model nonlinear thermoelasticity with one relaxation time generates thermal and mechanical waves propagating with finite speeds.

Thermo-elastic material parameters identification using modified error in constitutive equation approach

This paper presents an identification procedure for anisotropic thermo-elastic heterogeneous material profile based on modified error in constitutive equation (MECE) approach. The inverse problem is posed as an optimization problem where the objective functional evaluates the difference in constitutive relation that associates kinematically admissible strain field to the statically admissible stress field. An additional term due to corruption in measurement data is included in the cost functional as a penalty form. While following standard MECE-based identification procedure, we have proposed a trace norm of the constitutive discrepancy functional that arises due to two dissimilar fields for material parameter update. In the process, we obtain explicit parameter update formula for general anisotropic thermo-elastic material. However, unlike elastic case, parameter update equations are nonlinear due to thermo-elastic constitutive relation. Finally, the potential of the proposed procedure in estimating anisotropic material parameters is illustrated through some large-scale parameter estimation problems.

Plane wave propagation and domain of influence in fractional order thermoelastic materials with three-phase-lag heat transfer

ABSTRACTThe domain of influence theorem for the fractional order theory of anisotropic thermoelastic materials with three-phase-lag heat transfer is proposed. The fractional order theory of thermoelasticity with three-phase-lag heat transfer has been used to investigate the problem. The plane wave propagation in anisotropic thermoelastic medium having a fractional order derivative in the context of three-phase-lag model of thermoelasticity is studied. The governing equations for a transversely isotropic three-phase-lag model are reduced as a special case. Some wave characteristics are computed numerically and presented graphically.

Effect of the interrelationship of thermal and mechanical fields on the propagation of wave motions in cubically anisotropic thermoelastic materials

A characteristic equation for a system of equations of motion of a cubically anisotropic medium with allowance for the relaxation time of thermal disturbances has been obtained, and expressions for the velocities of propagation of modified elastic and thermal waves have been found. The surfaces of inverse velocities have been constructed and the influence of the effect of interrelationship of thermal and mechanical fields on the change in the phase velocities of propagation of a quasilongitudinal elastic wave and a thermal wave in different planes of a cubically anisotropic material has been analyzed.

Spatial Behavior in the Strongly Elliptic Anisotropic Thermoelastic Materials

In the present article we consider a prismatic semi-infinite cylinder occupied by an anisotropic homogeneous compressible linear thermoelastic material having an elasticity tensor that is strongly elliptic. The cylinder is subjected to zero body force and heat supply, zero displacement–temperature variation on the lateral boundary and pointwise specified displacement–temperature variation over the base. The main purpose of this contribution is to examine how certain measures of the displacement–temperature variation evolve with respect to the axial variable, provided that the strong ellipticity of the elasticity tensor is assumed. To this end, some appropriate measures are associated with the displacement–temperature variation and then an appropriate second-order differential inequality is established under the strong ellipticity condition on the elasticity tensor. The results are specialized for transversely isotropic and rhombic systems of elastic materials.

2209 異方性熱・弾性材料によるヒトの筋の収縮に関する数値モデリング(OS22.計算バイオメカニクス(2),ポスターセッションP-3)

2209 異方性熱・弾性材料によるヒトの筋の収縮に関する数値モデリング(OS22.計算バイオメカニクス(2),ポスターセッションP-3)

A continuum theory for viscoelastic composite beams

A dynamical continuum theory is developed for laminated composite beams. Starting with an assumed displacement- and temperature field, the one-dimensional approximate theory is consistently constructed within the frame of the three-dimensional theory of linear, nonisothermal, anisotropic, coupled viscoelasticity. Each constituent of the beam may possess different constant thickness and mechanical properties. All dynamic interactions between the adjacent constituents are included. Further, the effects of transverse shear and normal strains and rotatory inertia as well as those of cross-sectional distortion are all taken into account. The resulting equations consist of the macroscopic beam equations of motion and heat conduction, the kinematical relations, the initial and boundary conditions and the constitutive equations, and they govern the extensional, flexural and torsional motions of laminated composite beams. The special cases of constituents which made of either isotropic thermoviscoelastic or anisotropic thermoelastic materials are discussed briefly.

Acceleration waves in anisotropic thermoelastic materials with internal state variables

This work is concerned with the effect of internal state variables on the growth and decay properties of acceleration waves in anisotropic nonlinear thermoelastic materials. Sufficient conditions are given which insure the existence of a plane longitudinal acceleration wave and two transverse acceleration waves with orthogonal amplitudes.