Plate element with cutouts for finite element analysis of shear walls

Abstract

A rectangular plate element with rectangular cutouts was developed in this study. The aspect ratio of the cutout is almost arbitrary in the case of rectangles. The stiffness matrix of this new element is formed by modified numerical integration in which the region of the cutout in the element is excluded during the integration process. Nonconforming displacement modes are added to the stiffness matrix of the solid plate to soften the element. But they are not added to the region of cutouts. For the element which has several cutouts, the stiffness matrix is obtained in the same way as that of a simple cutout. The final stiffness matrix is formed by subtracting the summation of the matrices of several cutouts. Various numerical analyses were performed to verify the efficiency of this new element. The results of this study are compared with those from a well-established finite element program. Considering the location of cutouts, the effect of the sizes of cutouts and the case with multiple cutouts, the results are compared to verify the efficiency of the element. The results are very good and economical in this study. This element can be used effectively in the analysis of perforated shear walls. As the stresses were computed at the Gauss integration points in each element and the stresses at other locations were extrapolated or interpolated from the stresses at the Gauss points, the high local stress concentrations at the corners of the cutouts in the element were not obtained with this element.