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用有限元分析方法对平面应力、平面应变状态下2 1/4Cr-1Mo-18Cr8Ni复合板不同复合层中垂直于界面裂纹尖端应力应变场进行了计算和分析。同时作了从不同材料侧面开始的疲劳裂纹扩展试验。结果表明,在界面处满足变形相容的条件下,应力场分布在界面处有间断。由于裂纹应力场的间断和由此产生的HRR奇异性发生变化,界面对疲劳裂纹扩展速率有明显影响。这种影响受界面处△σ_(YY)、的控制。应力增量△σ_(YY)、反映了界面两侧材料性质的差异,与裂纹尖端塑性区相关连。
The stress-strain field perpendicular to the interface crack tip in different composite layers of 2 1 / 4Cr-1Mo-18Cr8Ni composite plate under plane stress and plane strain was calculated and analyzed by finite element method. At the same time made from the side of the different materials fatigue crack growth test. The results show that the stress field distribution is discontinuous at the interface under the condition of satisfying the deformation compatibility at the interface. Due to the discontinuity of the crack stress field and the resulting HRR singularity, the interface has a significant effect on the fatigue crack growth rate. This effect is controlled by Δσ_ (YY) at the interface. The stress increment △ σ_ (YY), which reflects the difference of material properties on both sides of the interface, is related to the plastic zone of the crack tip.