【作者】 胡伟平； 石文静； 张淼； 孟庆春；

【Author】 Hu wei-ping,Shi wen-jing,Zhang Miao,Meng qing-chun (Institute of Solid Mechanics,School of Aeronautics Science and Engineering, BeiHang University,Beijing 100191,China)

【机构】 北京航空航天大学航空科学与工程学院固体力学研究所；

【摘要】 <正>疲劳损伤失效是复合材料使用过程中一种常见的、对结构安全性和使用性影响严重的问题。从20世纪70年代开始,国内外学者就这一问题开始研究,取得了较多的研究成果,但是由于复合材料疲劳损伤机理复杂,很多问题仍处于探索当中。本文以纤维增强复合材料为研究对象,提出了一更多还原

【Abstract】 Composite materials are widely used in numerous applications due to their excellent overall properties.The safety of composite material structures are greatly influenced by fatigue failure,a serious damage mode.Since 1970s,researches has began to study on this issue,and obtained a lot of achievements; however,because of the complication of the fatigue mechanism of composite materials,many problems still remain unsolved. Research proposes a model to predict the fatigue life of the fiber-reinforced composite lamina based on the continuum damage mechanics.Firstly,the elastic constants of the fiber and the matrix are used to express the stiffness matrix of the fiber-reinforced composite lamina based on micromechanics.Two independent damage variables,the damage degree of the fiber and the damage degree of the matrix,are introduced to establish the constitutive relation with damage of the fiber-reinforced composite lamina in the basis of continuum damage mechanics.The fatigue damage issue of the lamina is transformed into the fatigue damage issue of the fiber and matrix.Secondly,the damage driving forces and the damage evolution equations of the fiber and the matrix are then set up respectively according to thermodynamics. Thirdly,the tension-tension fatigue test on the standard specimen of the 90°unidirectional laminates is used to identify the parameters for matrix damage evolution equation,and the tension-tension fatigue test on the 0°unidirectional laminates standard specimen is presented to identify the parameters for fiber damage evolution equation.Fourthly,the failure criterion for the lamina is then constructed under the two independent damage modes.Finally,the method of prediction fatigue life for the fiber-reinforced composite lamina is proposed and the fatigue lives of the lamina for different off-axis angles are predicated. Research provides a new theory and method for the analysis of the fatigue issue of fiber-reinforced composite lamina.According to the method,it only needs a small number of fatigue tests of standard specimen to obtain the material parameters in damage evolution equation,which is convenient for practice. Research supplies a basis for further analysis of the fatigue life of the composite laminate also.更多还原