Correction of full-field rigid body rotation and strain using a hybrid peridynamics and digital image correlation approach

Abstract

Rigid body rotation is difficult to be removed independently while using digital image correlation (DIC) technique for monitoring the displacement and deformation of an object. Furthermore, strain measurement can also become inaccurate due to the presence of displacement caused by rigid body rotation. Common solutions to this problem, such as tracking a single-point's rotation, require additional reference information and only obtain one rigid body rotation angle of the object. In this study, a hybrid computational and experimental mechanics method based on peridynamics (PD) and DIC technique is proposed to measure the full-field rigid body rotation and strain. A DIC-based PD model can be established based on the full-field position data obtained by DIC. The calculation formulas for rigid body rotation and strain are derived in the framework of PD and the calculations of rotation and strain are mutually insensitive and independent. Therefore, without any additional reference information, the rigid body rotation and strain information can be obtained in the presence of simultaneous rigid body rotation and deformation. Different rigid body rotations in various regions of an object, whether large or small rotations, can be calculated by this method. Correspondingly, this method is effective for calculating the local rigid body rotations of objects undergoing local fracture. Numerical simulations and experimental tests were performed to verify the effectiveness of the proposed method. The calculation results show that the proposed method owns the ability to accurately calculate the rotation and strain in the above scenarios.