In this work, the mechanics of ductile fracture near a notch tip in a basal textured Mg alloy is investigated through crystal plasticity based finite element analysis. An array of circular voids ahead of the tip subjected to mode I, plane strain, small scale yielding conditions is modelled. The effect of plastic anisotropy is examined by considering two notch orientations and contrasting the results against an isotropic plastic solid. The notch and the line perpendicular to it are chosen parallel to the transverse and rolling directions (TD and RD) in the first orientation, and along normal direction (ND) and TD in the second orientation. The TD-RD and isotropic cases show void-by-void growth for low initial porosity, $f_{v0}$, and simultaneous multiple void growth for high $f_{v0}$. By contrast, the ND-TD orientation displays the former even at high $f_{v0}$. This is attributed to slower porosity evolution with $J$ for this case due to high macroscopic hardening in the voided cells caused by pyramidal $<$c+a$>$ slip and tensile twinning. The predicted crack growth resistance curves are also strongly influenced by $f_{v0}$ and notch orientation.

在这项工作中，通过基于晶体塑性的有限元分析研究了基底织构镁合金中缺口尖端附近的延性断裂力学。对尖端前面的圆形空隙阵列进行了建模，这些空隙受到模式 I、平面应变、小规模屈服条件的影响。通过考虑两个缺口方向并将结果与​​各向同性塑性固体进行对比来检查塑性各向异性的影响。选择凹口和垂直于其的线在第一方向上平行于横向和滚动方向（TD和RD），在第二方向上沿着法线方向（ND）和TD。TD-RD 和各向同性情况显示初始孔隙率较低时逐个空隙生长，$F_{v0}$，以及同时多个空隙生长的高$F_{v0}$。相比之下，即使在高光下，ND-TD 方向也显示出前者。$F_{v0}$。这是由于孔隙度演变较慢$J$对于这种情况，由于锥体造成的空隙细胞中的高度宏观硬化$<$c+a$>$滑移和拉伸孪生。预测的裂纹扩展阻力曲线也受到以下因素的强烈影响：$F_{v0}$和凹口方向。