整个应力场对裂纹失稳扩展轨迹的影响

Influction of Whole Stress Field on the Unstable Crack Path

本文通过对凸形板试件对称边裂纹失稳扩展轨迹的实验研究和有限元计算，证实了裂纹失稳扩展轨迹是由失稳扩展前一瞬间的整个应力场决定的。研究表明：周向主应力判据比最大周向拉应力判据能更高精度地预测失稳裂纹的扩展轨迹。以上结论与薛昌明等人的相吻合。

On the basis of experimental the finite element analyes, the unstable crack pathof symmetry side cracks in convex plate is studied. It is shown that the path is determined by thewhale stress field existing just before the onset of instability. Moreover, the circuniferntial mainstress criterion is more precise than the maximum tenable ines criterion in predicahng the unstablecrack path. This Conclndon agrees well with that from G. C. Sih etc.