Notched bimaterials: An inverse problem methodology appraisal

The joining of dissimilar materials occurs and is common to MEMS devices and other structures critical to everyday usage. The problem of a notched bimaterial interface is of particular interest for some of these applications, where in an effort to gain greater insight, an inverse problem methodology may be applied. Considering only the birefringent or photoelastic response of a notched bimaterial interface it is possible to define several inverse problems: (a) For known geometry and material properties determine the applied boundary loads; (b) for known geometry and applied boundary loads determine the material properties of all material components; and, (c) for known geometry, applied boundary loads and materials properties determine the susceptibility to fracture of the bimaterial interface. This paper examines, because of the complexity of the needed geometries, the use finite element model (FEM) updating to illustrate the viability of solving the first two inverse problems posed above. The solutions are found to be repeatable and robust.