Identification of Boundary Condition from Measured Displacements for Linear Elastic Deformation Fields

An experimental-numerical hybrid method is proposed for obtaining reliable and accurate stress and strain distributions from measured displacement fields. Tractions acting at the boundary of the local analysis region are inversely determined from the measured displacements inside that region. Then, stresses are obtained by finite element direct analysis by applying the computed boundary condition. Effectiveness is validated by applying the proposed method to the displacement fields around a hole in a perforated plate obtained by electronic speckle pattern interferometry, and the displacement fields around a crack tip obtained by digital image correlation. Results show that the boundary condition for a local finite element model can be determined from the measured displacements and then the accurate and reliable stresses can be obtained by the proposed method. It is expected that the proposed method can be powerful tool for stress analysis.