HYSTERESIS MODELING OF WOOD JOINTS AND STRUCTURAL SYSTEMS

General features of the hysteretic behavior of wood joints and structu ral 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 sy stems. The hysteretic constitutive law produces a smoothly varying hys teresis that models previously observed behavior of wood joints and st ructural systems, such as nonlinearity, strength and stiffness degrada tion, and pinching. It takes into account the experimentally observed dependence of wood joints' response to the input and response at an ea rlier time (known as memory). Hysteresis shapes produced by the model are shown to compare favorably with experimental hysteresis of wood jo ints with (1) yielding plates; (2) yielding nails; and (3) yielding bo lts.