划痕缺陷对30Ni4CrMoA试样疲劳寿命影响的试验与理论模型  

Experimental and theoretical model study on influence of scratch defects on fatigue life of 30Ni4CrMoA sample

作　　者：张梦伟 胡伟平[1,2] 徐海斌 马占齐 詹志新 孟庆春 ZHANG Mengwei;HU Weiping;XU Haibin;MA Zhanqi;ZHAN Zhixin;MENG Qingchun(School of Aeronautic Science and Engineering,Beihang University,Beijing 100191,China;National Key Laboratory of Strength and Structural Integrity,Beijing 100191,China;Harbin Aircraft Industry Group Co.,Ltd.,Harbin 150066,China)

机构地区：[1]北京航空航天大学航空科学与工程学院,北京100191 [2]强度与结构完整性全国重点实验室,北京100191 [3]哈尔滨飞机工业集团有限责任公司,哈尔滨150066

出　　处：《航空学报》2025年第3期281-295,共15页Acta Aeronautica et Astronautica Sinica

基　　金：国家自然科学基金(12002011)。

摘　　要：制备了30Ni4CrMoA高强度结构钢的光滑试样以及不同划痕深度缺陷的试验件,并对这些试验件进行了疲劳试验测试,获得了含不同深度划痕缺陷和不同应力水平下试验件的疲劳寿命。基于连续损伤力学理论,在原有高周疲劳损伤演化方程的基础上,根据划痕根部最大应力分析与划痕深度的关系,以及试样疲劳寿命随划痕深度和应力水平的变化规律,提出了一种综合考虑划痕深度和应力水平影响的划痕影响系数表达式,建立了一种新的考虑划痕影响的等效疲劳损伤演化方程。基于该方程,无需建立划痕的有限元模型,直接采用闭合解法根据积分形式的疲劳寿命表达式即可对含划痕的30Ni4CrMoA试样进行疲劳寿命预估,理论预测结果与试验结果吻合很好,验证了所提方法的有效性和适用性。最后,还讨论了划痕影响系数与缺口疲劳系数的关系,以及划痕根部应力梯度的影响。The smooth samples of 30Ni4CrMoA high strength structural steel and the test parts with depth scratch de⁃fects of different depths were prepared,and the fatigue life of the test parts with scratch defects of different depths and different stress levels were obtained.Based on the theory of continuous damage mechanics and the original high-cycle fatigue damage evolution equation,an expression for influence of scratch coefficient was proposed,which compre⁃hensively considered the influences of scratch depth and stress level,according to the relationship between the maxi⁃mum stress analysis at scratch root and scratch depth,as well as the change law of sample fatigue life with scratch depth and stress level.A new equivalent fatigue damage evolution equation considering the effects of scratches was established.Based on this equation,the fatigue life of 30Ni4CrMoA sample with scratches can be predicted by the closed solution directly according to the fatigue life expression in the integral form,without establishing the finite ele⁃ment model of scratches.The theoretical prediction results are in good agreement with the experimental results,which verifies the effectiveness and applicability of the proposed method.Finally,the relationship between the scratch influ⁃ence coefficient and notch fatigue coefficient and the influence of stress gradient at scratch root were discussed.

关 键 词：划痕缺陷 疲劳 寿命预估 30Ni4CrMoA高强度结构钢 连续损伤力学 

分 类 号：V215.5[航空宇航科学与技术—航空宇航推进理论与工程]