Generic element matrices suitable for finite element model updating

Abstract Updating procedures are concerned with the construction of mass, stiffness and (possibly) damping matrices, near to some base matrices, which yield some response data close to some experimental values. One of the fundamental questions in updating relates to the criteria for allowable mass and stiffness matrices. In practice the updated matrices are often not physically meaningful. In this paper we start from the element level and consider what criteria must be satisfied by the element mass and stiffness matrices, and thus what parameters there are which can be optimised in the updating. We show that the recognised matrices appearing in special finite element formulations are members of families which may be obtained, in a logical manner, by applying these criteria.