Inverse finite element vibration problems

The paper concerns the reconstruction of a consistent FEM model of an in-li ne system of 2-dof elements, fixed at one end and free at the other. Such a system has tridiagonal stiffness and mass matrices, K, M. Because each ele ment has one rigid body mode, K has negative codiagonal and is constrained to have a particular form. M has positive codiagonal. It is shown how to co nstruct (an infinite family of) such models so that each has a specified un damped frequency response at the free end, and how to construct a system wi th a damper at the free end so that the system has specified (complex) eige nvalues. (C) 1999 Academic Press.