Analysis of 3-D foundation wave problems by mapped dynamic infinite elements (Q1117781)

From wave equations of 3-D viscoelasticity and Galerkin weighted residual approximation, discretized formulations for 3-D viscoelastic foundations have been derived. In addition, a 3-D mapped dynamic infinite element (IFEM) and its basic principle and constituting procedure are presented. This IFEM can easily be coupled with the normal FEM, and it retains the advantage of being suitable for simulation of complicated media and boundary conditions, and of reducing the degrees of freedom by a large number. The example given in this paper verifies the excellent accuracy of IFEM. Finally, study has been made to evaluate the effects of plate flexibility on dynamic compliances of a 3-D foundation on elastic half space. Results show that only if the elastic modulus ratio of the plate and foundation \(E_ F/E_ R\geq 10^ 4-10^ 5\), can the plate be treated as a rigid base.