Hysteresis Modeling of Wood Joints and Structural Systems

General features of the hysteretic behavior of wood joints and structural systems are characterized, and the available hysteresis models for wood systems are reviewed. A general hysteresis model for single- and multiple-degree-of-freedom wood joints and structural systems, based on a modification of the Bouc-Wen-Baber-Noori model, is presented and used in nonlinear dynamic analysis of single-degree-of-freedom wood systems. The hysteretic constitutive law produces a smoothly varying hysteresis that models previously observed behavior of wood joints and structural systems, such as nonlinearity, strength and stiffness degradation, and pinching. It takes into account the experimentally observed dependence of wood joints' response to the input and response at an earlier time (known as memory). Hysteresis shapes produced by the model are shown to compare favorably with experimental hysteresis of wood joints with (1) yielding plates; (2) yielding nails; and (3) yielding bolts.