MODELING AND RANDOM VIBRATION ANALYSIS OF SDOF SYSTEMS WITH ASYMMETRIC HYSTERESIS

This study focuses upon SDOF systems having non-linear, hysteretic str ess-strain behavior which is asymmetric about the initial linear elast ic relationship. Differences between tensile and compressive strength witnessed in various materials, particularly in the unique stress-stra in properties of the shape-memory alloy Nitinol, motivate the need for mathematical models capable of simulating asymmetric response. Two mo dels are presented, and the specific capabilities of each are explored . Both models follow the rate-type format of the Bouc-Wen model, and o ffer previously unavailable stress-strain relationships. Response stat istics under Gaussian White Noise input are obtained using the method of equivalent linearization. For asymmetric systems, a need for non-ze ro-mean analysis is evident, even under zero-mean input. (C) 1997 Else vier Science Ltd.