FINITE ELEMENT CONNECTIVITIES FROM VIBRATION MEASUREMENTS

This paper addresses the problem of determining unknown physical connectivities for inclusion in a finite element model by using standard frequency response measurements. In general, neither the topology nor the stiffness of such connectivities are known. A method is presented based on two systems of equations from finite elements and vibration measurements. When the equations are constrained so that an assumed connection is undeformed, then the eigenvalues and vectors of the two systems will be identical if the remainder of the structure is accurately modelled. A numerical example, in the form of a finite element truss structure, is used to illustrate the application of the method. It is demonstrated that the approach is tolerant of parameter errors elsewhere in the model.