对向方向角法
method by reciprocal bearings
裂缝起裂角
refracturing initiation angle
起裂角β0
crack initiation angle β0
翼裂纹起裂角
initiation angle of wing crack
开裂方向
direction of crack initiation
开裂方向预测
crack direction prediction
破裂方向性效应
Rupture directivity effect
折裂方向
direction of the fracture
初始主应力方向角
initial orientation of principal stress
continuous rotation of principal stress direction
大主应力方向角
angle of large principal stress direction