Effect of cracks on seismic response of plane frames

A newly developed model, which is validated and discussed in a companion paper, is extended to include the seismic response analysis of plane frames containing stationary cracks. This model takes into consideration effects of crack size and location, geometry of the frame, support conditions, and seismic ground motion characteristics. An extensive parametric study is carried out to investigate the seismic response of cracked plane frames. The analysis is carried out utilizing the developed computer program, which is based on finite element method and fracture mechanics techniques. Several numerical examples are investigated including a portal frame, a four-story three-bay frame, and an eight-story three-bay frame. The frames are analyzed under the effect of three different seismic acceleration response spectra and for various crack locations. It is found that crack presence generally increases building drift, modifies the seismic forces and causes redistribution of bending moments.