RESPONSE OF A STRIP WITH CIRCULAR CAVITY TO HARMONIC FORCES

摘要

In this paper, the response of a strip with a circular cavity to a pair of harmonic forces is investigated by applying elastodynamic theory. The field is decomposed into two parts : the one is the free wave field in the strip without cavity and the scattered wave field generated by the cavity. The scattered field is contributed by the series of the source terms which consist of the line sources of P-wave and SV-wave with different orders along y-direction, and their corresponding reflective waves from the plane boundaries. Both source and reflective waves are expressed in terms of integrals which can be evaluated numerically by applying the modified steepest descend method proposed by Yeh et al. (1998). The coefficients of the series are determined by choosing the collocation points around the boundary of the cavity and applying the least square method. Then the displacements and the stresses around the boundary are calculated numerically. The numerical results are shown in diagrams for different frequen-cies. The dynamic stress concentration is defined and discussed in detail.