考虑到如紧凑拉伸和三点弯曲等标准试样的大尺寸要求以及高试验成本等突出问题,该文发展了含外侧径向裂纹C形环小试样(C-ring with an outer radial crack,CRO)的疲劳裂纹扩展行为试验方法。利用有限元分析建立了CRO小试样的高精度应力...考虑到如紧凑拉伸和三点弯曲等标准试样的大尺寸要求以及高试验成本等突出问题,该文发展了含外侧径向裂纹C形环小试样(C-ring with an outer radial crack,CRO)的疲劳裂纹扩展行为试验方法。利用有限元分析建立了CRO小试样的高精度应力强度因子算式以及基于柔度法理论的裂纹长度预测公式。采用5083-H112铝合金分别完成了CRO试样和标准CT试样的疲劳裂纹扩展速率试验,获得了相应的Paris方程中的幂指数。通过对比发现,CRO和CT试样的疲劳裂纹扩展规律基本一致,验证了新方法的有效性。基于上述方法对C250钢两种厚度CRO试样的疲劳裂纹扩展行为进行了应用研究。展开更多
Based on experiments of low cycle fatigue for 5083-H112 aluminum alloy, two energybased predictive models have been introduced to predict the fatigue crack growth behaviors of traditional Compact Tension（CT） and sma...Based on experiments of low cycle fatigue for 5083-H112 aluminum alloy, two energybased predictive models have been introduced to predict the fatigue crack growth behaviors of traditional Compact Tension（CT） and small-sized C-shaped Inside Edge-notched Tension（CIET）specimens with different thicknesses and load ratios. Different values of the effective stress ratio U are employed in the theoretical fatigue crack growth models to correct the effect of crack closure.Results indicate that the two predictive models show different capacities of predicting the fatigue crack growth behaviors of CIET and CT specimens with different thicknesses and load ratios.The accuracy of predicted results of the two models is strongly affected by the method for determination of the effective stress ratio U. Finally, the energy-based Shi＆Cai model with crack closure correction by means of Newman＇s method is highly recommended in prediction of fatigue crack growth of CIET specimens via low cycle fatigue properties.展开更多
文摘考虑到如紧凑拉伸和三点弯曲等标准试样的大尺寸要求以及高试验成本等突出问题,该文发展了含外侧径向裂纹C形环小试样(C-ring with an outer radial crack,CRO)的疲劳裂纹扩展行为试验方法。利用有限元分析建立了CRO小试样的高精度应力强度因子算式以及基于柔度法理论的裂纹长度预测公式。采用5083-H112铝合金分别完成了CRO试样和标准CT试样的疲劳裂纹扩展速率试验,获得了相应的Paris方程中的幂指数。通过对比发现,CRO和CT试样的疲劳裂纹扩展规律基本一致,验证了新方法的有效性。基于上述方法对C250钢两种厚度CRO试样的疲劳裂纹扩展行为进行了应用研究。
基金financially supported by the National Natural Science Foundation of China (Nos. 11202174 and 11472228)
文摘Based on experiments of low cycle fatigue for 5083-H112 aluminum alloy, two energybased predictive models have been introduced to predict the fatigue crack growth behaviors of traditional Compact Tension（CT） and small-sized C-shaped Inside Edge-notched Tension（CIET）specimens with different thicknesses and load ratios. Different values of the effective stress ratio U are employed in the theoretical fatigue crack growth models to correct the effect of crack closure.Results indicate that the two predictive models show different capacities of predicting the fatigue crack growth behaviors of CIET and CT specimens with different thicknesses and load ratios.The accuracy of predicted results of the two models is strongly affected by the method for determination of the effective stress ratio U. Finally, the energy-based Shi＆Cai model with crack closure correction by means of Newman＇s method is highly recommended in prediction of fatigue crack growth of CIET specimens via low cycle fatigue properties.
