Identification of Inelastic Shear Frames Using the Prandtl-Ishlinskii Model

In this paper, a new method is proposed for identification of inelastic shear frame structures with hesteresis, using data collected on their dynamic response. it uses the prandtl-ishlinskii rate independent model for hysteresis, which was originally used in the field of plasticity and fervornagnetism. the proposed identification method is capable of identifying the mass, damping and restoring force of a frame structure, which can he used in forming the equations of motion of the frame. by solving the equations of motion, the dynamic response is predicted. the 'method is based on the combined use of quadratic programming (qp) and genetic algorithms (ga). first, assuming a set of prandtl-ishlinskii constants, the qp is used to find the best frame parameters that can be used in its equations of motion to predict its dynamic response with the minimum of error compared to the real data collected on its dynamic response, while the ga is used to find the best prandtl-ishlinskii constants for more reduction in error. the method has been applied to different frames with bilinear nonlinearity where the results show the high capability of the method. two examples, a single and a multi degree of freedom (sdof and mdof) frame, are included in the paper.