A new cyclic cohesive zone fatigue damage model is proposed to address the fatigue problem spanning highand low cycle stages.The new damage model is integrated with the damage extrapolation technique to improvecalcula...A new cyclic cohesive zone fatigue damage model is proposed to address the fatigue problem spanning highand low cycle stages.The new damage model is integrated with the damage extrapolation technique to improvecalculation efficiency.The model’s effectiveness in regulating the low-cycle fatigue evolution rate,overall fatiguedamage evolution rate,and stress level at the fatigue turning point is assessed through the comparison of the S-Ncurves.The fatigue damage model’s high precision is proved based on the minor deviation of stress at the turningpoint of the S-N curve from the actual scenario.Finally,the fatigue damage evolution is simulated consideringthe effects of pre-load pressure and welding residual stress.It is observed that laser welding induces a significantresidual tensile stress,accelerating fatigue damage evolution,while compressive loading impedes fatigue damageprogression.展开更多
In the paper, a new procedure is proposed to investigate three-dimensional fracture problems of a thin elastic plate with a long through-the-thickness crack under remote uniform tensile loading. The new procedure incl...In the paper, a new procedure is proposed to investigate three-dimensional fracture problems of a thin elastic plate with a long through-the-thickness crack under remote uniform tensile loading. The new procedure includes a new analytical method and high accurate finite element simulations. In the part of theoretical analysis, three-dimensional Maxwell stress functions are employed in order to derive three-dimensional crack tip fields. Based on the theoretical analysis, an equation which can describe the relationship among the three-dimensional J-integral J(z), the stress intensity factor K(z) and the tri-axial stress constraint level Tz(z) is derived first. In the part of finite element simulations, a fine mesh including 153360 elements is constructed to compute the stress field near the crack front, J(z) and Tz(z). Numerical results show that in the plane very close to the free surface, the K field solution is still valid for in-plane stresses. Comparison with the numerical results shows that the analytical results are valid.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.11932006,12202314,12172121,and 12002118).
文摘A new cyclic cohesive zone fatigue damage model is proposed to address the fatigue problem spanning highand low cycle stages.The new damage model is integrated with the damage extrapolation technique to improvecalculation efficiency.The model’s effectiveness in regulating the low-cycle fatigue evolution rate,overall fatiguedamage evolution rate,and stress level at the fatigue turning point is assessed through the comparison of the S-Ncurves.The fatigue damage model’s high precision is proved based on the minor deviation of stress at the turningpoint of the S-N curve from the actual scenario.Finally,the fatigue damage evolution is simulated consideringthe effects of pre-load pressure and welding residual stress.It is observed that laser welding induces a significantresidual tensile stress,accelerating fatigue damage evolution,while compressive loading impedes fatigue damageprogression.
基金supported by the Fundamental Research Funds for the Central Universities(Grant No.2014B1801)
文摘In the paper, a new procedure is proposed to investigate three-dimensional fracture problems of a thin elastic plate with a long through-the-thickness crack under remote uniform tensile loading. The new procedure includes a new analytical method and high accurate finite element simulations. In the part of theoretical analysis, three-dimensional Maxwell stress functions are employed in order to derive three-dimensional crack tip fields. Based on the theoretical analysis, an equation which can describe the relationship among the three-dimensional J-integral J(z), the stress intensity factor K(z) and the tri-axial stress constraint level Tz(z) is derived first. In the part of finite element simulations, a fine mesh including 153360 elements is constructed to compute the stress field near the crack front, J(z) and Tz(z). Numerical results show that in the plane very close to the free surface, the K field solution is still valid for in-plane stresses. Comparison with the numerical results shows that the analytical results are valid.
