A Thermoelastic Stress Analysis General Model: Study of the Influence of Biaxial Residual Stress on Aluminium and Titanium

All the studies on the thermoelastic behaviour of materials, including the revised higher order theory on the thermoelastic effect, are based on several assumptions that limit the application of such theory to the cases of isotropic materials in the presence of uniaxial residual stresses and undergoing uniaxial applied loads. These assumptions lead to some discrepancies in the description of the real thermoelastic behaviour of materials in the presence of residual stresses. In this work, by rewriting the thermoelastic equation in a different way, it was possible to study the behaviour of homogeneous and non-isotropic materials undergoing any loading conditions and residual stresses. Firstly, the error made by the calibration procedures of thermoelastic stress analysis (TSA) data in the presence of residual stresses has been investigated. Then, a statistical analysis was carried out to determine the minimum value of residual stress which would lead to significant and measurable variations in the thermoelastic signal. The simulations involved two non-ferrous metals: AA6082 and Ti6Al4V, which exhibit a specific thermoelastic behaviour.

Further results for a one-dimensional linear thermoelastic equation with Dirichlet-Dirichlet boundary conditions

We show that a sequence of generalized eigenfunctions of a one-dimensional linear thermoelastic system with Dirichiet-Dirichlet boundary conditions forms a Riesz basis for the state Hilbert space. This develops a parallel result for the same system with Dirichlet-Neumann or Neumann-Dirichlet boundary conditions.

Analysis of Thermal Shock on Nuclear Power Station Pump

In this paper, a heat conduction equation and a dynamic thermoelastic equation are briefly deduced and established based on Continuum Mechanics. First, an qualitative discussion is emphatically centered around the couple term and the dynamic term of the equation by means of the dimensional analysis and by considering the combination of the characteristics of the materials and of the thermal load effected on the nuclear power station pump under study. Second, formulations of the FEM for non-coupled heated equations and quasi-static thermoelastic equations are derived in this paper. Third, a half space thermal shock problem is used as a computational example in the highlighted research on the varying behavior of the dynamic thermal stress on the temperature slope. The conclusion of the paper provides reliable justification for applying the numerical method. Finally, the distribution and variety of the temperature field, the thermal stress field and the thermal deformation field at various transient moments on the pump are given.