A new model to Describe yield surface distortion based on the Baltov’s model

In the present study Baltov’s yield surface model ismodified to represent compatible results with experimental observations. The proposed yield surface is determined during tension-torsion loading by considering kinematic hardening model and monotonic loading paths. The experimental results represent the nosed and flattened region in the loading and reverse loading direction respectively. Nosed region is more dominant in the tension than torsional loading. The cross-effect is negligible in the small plastic strain. The Baltov’s yield surface has nosed and flattened region in both loading and reversed loading directions for negative and positive added material parameter respectively. Thus the elliptic Baltov’s yield surface is modified by changing sign of this parameter continuously from loading to reverse loading direction and the needed relations of the new model were obtained. The new model was able to predict properly the shape of yield surface. The experimental results compare well with the new model yield surface distortion predictions

کلیدواژه ها:

Baltov model ، distortion of yield surface ، kinematic hardening