Numerical technique for dynamic analysis of structures with friction devices

Abstract

Abstract In recent years a number of studies on employing friction elements for the seismic protection of buildings has demonstrated conclusively that such devices can markedly reduce earthquake‐induced vibrations. Any numerical estimate of the effectiveness of such isolation systems implies a correct solution of the pertinent nonlinear equations of motion. In direct integration algorithms, the phase transitions between adherence and sliding, or the sliding phase may be accompanied by marked high‐frequency oscillation of the relative velocity difference. The paper presents a numerical technique for overcoming these problems, thus leading to increased accuracy of the solutions of equations of motions with Coulomb damping. Since only the damping matrix and the loading vector are involved, the procedure is also computationally efficient. In order to validate the proposed numerical technique, an experimental study of a friction system has been carried out. The dynamic response of a four‐storey braced frame with friction devices is presented as an example for the practical application of the proposed numerical technique.