Abstract
The present paper develops a direct boundary element formulation for coupled heat and moisture transfer of 1-dimensional multi-layered walls. The coupled boundary integral equations are derived, and the fundamental solutions are obtained as linear combinations of the solutions for 1-dimensional simple diffusions. Using constant boundary elements in time and linear cells in space, the boundary integral equations are descretized into the simultaneous algebraic equations. Then the coefficients of the system matrices are evaluated analytically. Based on the algebraic equations for a single layer, coupled heat and moisture transfer in multi-layered walls is formulated with unknown potentials of internal boundaries. Simple examples, that is, thermal and hygroscopic responses of a concrete wall subject to step excitations on direchlet boundaries, are computed and they illustrate the numerical efficiency and accuracy of the proposed method.
