Damage identification in structural joints using generic joint elements

This article considers the identification of damage in joints in a structure where no baseline model is available. Linear equations are formulated to relate the joint parameter variations caused by damage to the measured or simulated responses in the frequency domain. Generic joint elements with only translational degrees of freedom are defined to model the structure. For a particular type of joint, the generic joint element stiffness matrices are formed by using only the translational components of the mode shapes, which can be approximated intuitively or by a detailed finite element analysis of the joint. The methods are illustrated by a plane portal frame with both L- and T-shaped joints.