基于三维空间矢量应力场强法的SiCp/Al复合材料缺口疲劳强度预测  

Notched fatigue strength prediction of SiCp/Al composites based on the three-dimensional space vector stress field intensity method

作　　者：徐颖 杨涛 王学民 崔海涛 黄申 XU Ying;YANG Tao;WANG Xuemin;CUI Haitao;HUANG Shen(Jiangsu Province Key Laboratory of Aerospace Power System,College of Energy and Power Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China;Sichuan Gas Turbine Establishment,Aero Engine Corporation of China,Chengdu 610500,China)

机构地区：[1]南京航空航天大学能源与动力学院江苏省航空动力系统重点实验室,南京210016 [2]中国航发四川燃气涡轮研究院,成都610500

出　　处：《航空动力学报》2024年第4期111-119,共9页Journal of Aerospace Power

基　　金：中国航发四川燃气涡轮研究院外委课题。

摘　　要：为了考虑应力梯度对SiCp/Al复合材料结构疲劳强度的影响,基于三维空间矢量应力场强法和光滑件疲劳强度,发展了一种SiCp/Al复合材料缺口疲劳强度预测方法,其中三维空间矢量应力场强法计算中分别应用了经典一维应力场强与有效距离点应力场强的等效应力积分形式,避免了构建三维权函数和人为确定疲劳损伤区域。采用升降法制定了SiCp/2009Al复合材料光滑件疲劳试验方案,获得了SiCp/2009Al复合材料10^(7)循环周次对应的轴向(R=-1)疲劳强度为180.91 MPa,并以散点法开展疲劳试验获得了SiCp/2009Al疲劳寿命分布,光滑件疲劳试验结果显示SiCp/2009Al复合材料应力-寿命关系存在明显的平台区。采用逐级加载法开展了SiCp/2009Al复合材料缺口件轴向(R=-1)疲劳试验,获得了缺口件的疲劳强度为82.2 MPa。缺口件疲劳强度预测结果与试验结果吻合较好,最大误差在10%以内,其中基于有效距离点应力场强的三维空间矢量应力场强法建立的SiCp/Al复合材料缺口疲劳强度预测方法预测精度更高。In order to consider the influence of stress gradient on the fatigue strength of SiCp/Al composite structure,a notched fatigue strength prediction method of SiCp/Al composite was developed based on the three-dimensional space vector stress field intensity method(TSVFM)and the fatigue strength of smooth specimen.In the TSVFM,the equivalent stress integral forms of classic onedimensional stress field intensity method and effective distance point stress field intensity method were applied respectively,which avoided the construction of three-dimensional weight function and artificial determination of fatigue damage region.The fatigue test scheme of SiCp/2009Al composite smooth specimen was determined by up-and-down method,and the axial(R=-1)fatigue strength corresponding to 10^(7) cycles of SiCp/2009Al composite was 180.91 MPa.The fatigue life distribution of SiCp/2009Al was obtained by the scattered point method.The fatigue test results of smooth specimen showed that there was an obvious platform area in the stress-life relationship of SiCp/2009Al composite.The axial(R=-1)fatigue test of notched specimen of SiCp/2009Al composite was carried out by step-by-step loading method,and the fatigue strength of notched specimen was 82.2 MPa.The fatigue strength prediction results of notched specimen were in good agreement with the test results,and the maximum error was within 10%.The notched fatigue strength prediction method of SiCp/Al composites based on the ETSVFM was better than the CTSVFM.

关 键 词：SICP/AL复合材料 疲劳强度 缺口疲劳 三维应力场强 高周疲劳试验 

分 类 号：V1[航空宇航科学与技术—人机与环境工程]