Inelastic Behavior of Mortise-Tenon Jointed Traditional Timber Frame with Free-Standing Columns

This paper aims to study lateral behavior of the semi-mortise-tenon (SMT) jointed frame with free-standing columns with elastic-plastic deformations in the traditional timber building. The frictional and compressive forces at contact interfaces of SMT connection are calculated through the volumes of elastic and yielding deformations perpendicular-to-grain, and the compressive force is analyzed considering the elastic and yielding deformations parallel-to-grain at the bottom of column. The elastic-plastic behavior of timber frame with SMT and column foot (CF) connections under different vertical loads is assessed. The results reflect that the main plastic deformation of the timber frame occurs at SMT connections perpendicular-to-grain, and the effect of the plastic deformations parallel-to-grain at CF of the timber frame on its lateral resistance is relatively small, the lateral resistance of the wood frame shows a trilinear characteristic. Moreover, the gravity load of the upper structure does not directly affect the plastic deformation perpendicular-to-grain at SMT connections-the SMT connection of the timber frame with a larger gravity load of an upper structure is more likely in the plastic stage than that of a smaller gravity load of an upper structure.