Optimual Performance-based Seismic Design Of Structures Using Nonlinear Static Method

Building structures have traditionally been designed for seismic resistance byproviding adequate strength to against prescribed equivalent static loads. One majordrawback of this force-based design approach is that it does not directly address thepost-yielding deformability of structures and thus does not effectively control thedamage during earthquakes. Therefore,performance-based seismic design has beenrecognized.The paper presents an effective optimization technique for uniforminterstory drift performance design of frames. It based on the concept of uniformdistribution of deformation. In order to obtain the optimum distribution of structuralproperties, an iterative optimization procedure has been adopted. In this approach,the structural properties are modifed so that ineffcient material is gradually shiftedfrom strong to weak areas of the structure. This process is continued until a state ofuniform interstory drift is achieved.The shear-building of frame is presented toillustrate the effectiveness and practicality of the proposed optimal designmethod.The main contents include:(1)The seismic performance of structure is connected with structuralproperties and seismic load. To ensure that the structure achieve a uniform interstorydrift in severe earthquakes, the paper proposes a optimization design methodaccording to the result of structural nonlinear response to change the structure oftheir own features(2)The effectiveness and accuracy of the design method is verified by a six-sto-ry shear building designed by code-based design method. The seismic performance ofstructures designed by code-based and optimal method is compared. Heightwisedistribution of the interstory drift of optimum structure is uniform, and the maximumshear deformation and cumulative damage are reduced.(3)By conducting this algorithm on shear-building models with variousdynamic characteristics, the effects of fundamental period, earthquake intensity,lateral loading mode, the initial strength distribution, the convergence factor, postyield stiffness coefficient, the distribution of mass and story hight along thestructure and number of stories are investigated.