Influence of Plastic Zone and Tensile Stress Field Ahead of The Notch on The Arrest Crack Length Under Cyclic Compressive Fatigue
缺口根部塑性区和拉应力场对循环压缩疲劳裂纹止裂长度的影响

The shape and size of plastic zone ahead of double edge-notched specimens under different compressive load have been measured with micro-image-plane holography and speckle photography separating method(MIHSS). The plastic zone and the stress field ahead of the notch have also been calculated by finite element method. The results obtained show that the measurment is easy and accurate enough in engineering. Comparing the arresed crack length under cyclic compressive fatigue with the size of the compressive plastic zone shows that there is no simple correspondance between them and the arresed carck length is mainly controlled by the tensile stress field ahead of the notch produced during unloading in the compressive cycle.