Modeling transient elastodynamic problems using a novel semi-analytical method yielding decoupled partial differential equations

In this paper, a novel semi-analytical method is proposed for modeling of two-dimensional (2D) elastodynamic problems. In this regard, the domain boundary of the problem is discretized by specific non-isoparametric elements that are proposed for the first time in this paper. In these elements, special shape functions as well as higher-order Chebyshev mapping functions are implemented. For the shape functions, Kronecker Delta property is satisfied for displacement function and its derivatives, simultaneously. Moreover, the first derivatives of shape functions are assigned to zero at any given node. Finally, using a weak form of weighted residual method and implementing Clenshaw-Curtis numerical integration, coefficient matrices of the system of equations are converted into diagonal ones, which leads to a set of decoupled partial differential equations for solving the whole system. This means that the governing partial differential equation for each degree of freedom (DOF) becomes independent from other DOFs of the domain. Also, to assess the accuracy and efficiency of the proposed method, four benchmark problems of 2D elastodynamics are solved using a few numbers of DOFs. The numerical results present excellent agreement with the analytical solutions and the results from other numerical methods.