The EVPSC-TDT model is first employed to investigate the yield behavior of a strongly basal textured Mg alloy plate under biaxial loading. The material parameters are calibrated according to experimental uniaxial tension and compression along the rolling and plate normal directions. The EVPSC-TDT model with the calibrated parameters is then employed to conduct various biaxial loadings under plane stress condition. The predicted yield surface and its evolution match well with the experimental data. The shape change of the yield surfaces in all four quadrants is interpreted according to the activated deformation modes. Compressive twinning weakens the work hardening behavior in the first quadrant of the yield surface at relatively large plastic strain level, while tensile twinning plays an important role in determining the shape of the second, third and fourth quadrants of the yield surface. A turning point corresponding to pure shear loading is observed in the second quadrant of the yield surface which is caused by the transition of activated deformation modes from basal slip and tensile twinning to non-basal slip. In addition, the effect of initial texture on the shape of the yield surface of Mg alloy plates has been briefly investigated.

EVPSC-TDT模型首先用于研究在双轴载荷下强基底织构镁合金板的屈服行为。根据沿轧制和板法线方向的实验单轴拉伸和压缩来校准材料参数。然后，将具有校准参数的EVPSC-TDT模型用于在平面应力条件下进行各种双轴载荷。预测的屈服面及其演化与实验数据吻合良好。根据激活的变形模式来解释所有四个象限中的屈服面的形状变化。在较大的塑性应变水平下，压缩孪晶削弱了屈服面第一象限的加工硬化行为，而拉伸孪晶在确定第二象限的形状方面起着重要作用，屈服面的第三和第四象限。在屈服面的第二象限中观察到与纯剪切载荷相对应的转折点，这是由于激活变形模式从基滑和拉伸孪生过渡到非基滑而引起的。此外，已初步研究了初始织构对镁合金板屈服表面形状的影响。