Numerical-experimental hybrid method for stress separation in digital gradient sensing method. (March 2015)

• Record Type: Journal Article
• Authors: Zhang, Rui; Guo, Ran; Cheng, Heming
• Is Part Of: Optics and lasers in engineering. Volume 66(2015)
• Page Start: 122
• Page End: 127
• Publication Date: 2015-03
• Subjects: Digital gradient sensing method -- Boundary condition -- Finite element method -- Hybrid method -- Stress separation; Lasers in engineering -- Periodicals; Optical measurements -- Periodicals; Optics -- Periodicals; Lasers en ingénierie -- Périodiques; Mesures optiques -- Périodiques; Optique -- Périodiques; 621.36605
• DOI: 10.1016/j.optlaseng.2014.08.017
• Languages: English
• ISSNs: 0143-8166

Abstract

Abstract: A numerical-experimental hybrid method for the stress separation in the digital gradient sensing (DGS) method is proposed in this study. In the proposed hybrid method, boundary conditions for a local finite element model, that is, nodal force along boundaries are inversely determined from experimental values obtained by the digital gradient sensing method. The hybrid method follows two stages. In stage 1, the DGS method measures the Cartesian stress gradient components directly and, subsequently, the sum in Cartesian stresses at all interesting points on the surface; stress sum are used to compute the unknown boundary conditions for the local model. In stage 2, the individual stress components are calculated by the direct finite element method using the computed boundary conditions from stage 1. The effectiveness is demonstrated by applying the proposed method to a stress concentration problem involving concentrated load acting on an edge of a large planar sheet. The individual stress components thus determined are summed and compared with analytical stress sum, confirming the effectiveness and accuracy of the proposed technique.