Transient thermal analysis of a bi-layered composites with the dual-reciprocity inclusion-based boundary element method

This paper proposes a single-domain dual-reciprocity inclusion-based boundary element method (DR-iBEM) for a three-dimensional fully bonded bi-layered composite embedded with ellipsoidal inhomogeneities under transient/harmonic thermal loads. The heat equation is interpreted as a static one containing time- and frequency-dependent nonhomogeneous source terms, which is similar to eigen-fields but is transformed into a boundary integral by the dual-reciprocity method. Using the steady-state bimaterial Green’s function, boundary integral equations are proposed to take into account continuity conditions of temperature and heat flux, which avoids setting up any continuity equations at the bimaterial interface. Eigen-temperature-gradients and eigen-heat-source are introduced to simulate the material mismatch in thermal conductivity and heat capacity, respectively. The DR-iBEM algorithm is particularly suitable for investigating the transient and harmonic thermal behaviors of bi-layered composites and is verified by the finite element method (FEM). Numerical comparison with the FEM demonstrates its robustness and accuracy. The method has been applied to a functionally graded material as a bimaterial with graded particle distributions, where particle size and gradation effects are evaluated. • Formulate a single-domain algorithm of DR-iBEM for bi-layered composites. • Capture disturbances of ellipsoidal inclusions by closed-form bimaterial Eshelby’s tensors. • Extend equivalent inclusion method for transient heat transfer in a bi-layered domain. • Deliver high-fidelity local solutions with tailorable accuracy verified by FEM. • Build a cross-scale model for predicting the effective transient thermal behavior of FGMs.