Abstract
A method for determining boundary conditions and analyzing stresses and strains in two-dimensional elastic body from measured displacement distribution is described. Displacement distributions obtained by optical methods are represented by the superposition of the displacements obtained by finite element analyses under the boundary condition of unit force at a point on the boundary. The nodal force vector along the boundary of the analysis region is then determined from the measured and computed displacements using the method of least-squares. The stresses and strains inside the analysis region are obtained from the nodal forces along the boundary by direct analysis. The validity is demonstrated by applying the proposed method to displacement distributions obtained by finite element analysis and those obtained by digital image correlation. Results show that the stresses can be computed from the measured displacements accurately by the proposed method. Furthermore, the stresses near free boundaries and stress concentration region can be determined easily. As stresses can be evaluated easily and accurately, it is expected that the proposed method can be applied to various problems in solid mechanics.
