Design optimization of the cruciform specimen in a biaxial test using MADM methods

Abstract

ABSTRACT One of the most crucial aspects of biaxial testing is the geometry of the cruciform specimen. The optimised cruciform geometry leads to obtain adequate stress-strain data. Different geometries of the cruciform specimen were investigated in the last few years, but none of them could be considered as a standard cruciform geometry. It is desirable to have more homogeneous stress and maximum plastic strain in the central area of the specimen. The parameters such as slit width, corner radius, and thickness of the specimen were varied during the FE simulation. The FE tool Abaqus Explicit with von Mises yield criterion was used. Nine alternatives were framed by using Taguchi L9 orthogonal array approach for parametric randomisation. The Technique of Order Preference by Similarity to Ideal Solution (TOPSIS) and Simple Additive Weighting (SAW) methods were employed to evaluate the overall performance of each alternative. The optimised geometry was further analysed with different stress ratios and slit width by keeping other parameters constant. It was noticed that the average plastic strain was decreased from 1.43% to 1.35% and 3.66% to 3.33% with the change in slit width from 0.2 mm to 0.6 mm at loading ratio 1:1 and 2:1, respectively.