INSIGHT INTO DEFICIENCIES ASSOCIATED WITH COMMONLY USED ZERO-THICKNESS INTERFACE ELEMENTS

Although they are widely used in the finite element analysis of geolog ic structures, zero-thickness interface elements possess certain funda mental deficiencies. In particular, spurious stress oscillations attri buted to inappropriate quadrature schemes, lack of accuracy due to exc essively large stiffness parameters, and inaccurate interface stress p redictions due to insufficient mesh fineness have been cited in the pa st. In this paper the performance of two commonly used linear zero-thi ckness interface elements is examined in detail. Behavioral deficienci es that have not appeared in the literature are identified. Although s ome of these deficiencies are similar to phenomena previously noted fo r such elements, in the present case they are attributed to different factors. An improved linear zero-thickness interface element that over comes the aforementioned deficiencies is developed and its predictive capabilities critically assessed.