INVERSE ANALYSIS OF EXPERIMENTS FOR DETERMINING FRACTURE PROPERTIES OF STRAIN HARDENING CEMENT-BASED COMPOSITES

If cement-based materials are reinforced with fibers, they may exhibit a strain hardening behavior. As an alternative to expensive uniaxial tension tests, comparably simple bending tests may be conducted for determining the mechanical material properties of these strain hardening cement-based composites. However, the determination of the uniaxial hardening and softening behavior requires inverse analyses of the bending tests. A robust and effective method for the determination of the hardening curve by inverse analysis is proposed. It allows to determine the material's hardening curve up to the fracture localization point. The applied optimization procedure is based on an evolutionary algorithm. For the validation of the method, a cement mortar reinforced with polyvinyl alcohol fibers was tested. The inverse analysis results proved to be in good accordance with those of uniaxial tension tests.