Experimental study of non-linear effects in a typical shear lap joint configuration

Although mechanical joints are integral parts of most practical structures, their modelling and their effects on structural dynamics are not yet fully understood. This represents a serious impediment to accurate modelling of the dynamics and to the development of reduced-order, finite element models capable of describing the effects of mechanical joints on the dynamics. In this work we provide an experimental study to quantify the non-linear effects of a typical shear lap joint on the dynamics of two structures: a beam with a bolted joint in its center; and a frame with a bolted joint in one of its members. Both structures are subjected to a variety of dynamical tests to determine the non-linear effects of the joints. The tests reveal several important influences on the effective stiffness and damping of the lap joints. The possibility of using Iwan models to represent the experimentally observed joint effects is discussed.