Institute of Fundamental Technological Research

In this work, a new, simple method is presented, which enables identifcation of material properties of solids basing on the digital image correlation (DIC) measurements. It may be considered as a simplifed alternative of low computational complexity for the well-known fnite element model updating (FEMU) method and virtual felds method (VFM). The idea of the introduced sub-global equilibrium (SGE) method is to utilize the fundamental concept and defnition of internal forces and its equilibrium with appropriate set of external forces. This makes the method universal for the use in the description of a great variety of continua. The objective function is the measure of imbalance, namely the sum of squares of residua of equilibrium equations of external forces and internal forces determined for fnite-sized part of the sample. It is then minimized with the use of the Nelder–Mead downhill simplex algorithm. The efciency of the proposed SGE method is shown for two types of materials: 310 S austenitic steel and carbon-fber-reinforced polymer (CFRP). The proposed method was also verifed based on FE analysis showing error estimation.

Identifcation of material constant,Digital image correlation,Nelder–Mead downhill simplex algorithm,Finite element analysis,Optimization,Linear elasticity