金属基复合材料热机械疲劳寿命影响参数研究  

Effects of influential parameters on fatigue life of metal matrix composites under thermo-mechanical loading

作　　者：王放[1] 陈志谦[1] 吕世金[2] 

机构地区：[1]西南大学材料科学与工程学院,重庆400715 [2]中国船舶科学研究中心,江苏无锡214082

出　　处：《船舶力学》2010年第7期765-770,共6页Journal of Ship Mechanics

基　　金：国家自然科学基金资助项目(10772105);重庆市科委自然科学基金计划资助项目(CSTC;2009BB4290)

摘　　要：基于细观损伤机理,通过对金属基复合材料在热/机械循环载荷下疲劳破坏的数值模拟,研究了六种参数对疲劳寿命的影响。结果表明:(1)疲劳寿命随着试样尺寸的增大而缩短,但达到临界尺寸,即纤维规模超过25根或者长度超过30倍纤维直径后,疲劳寿命将不受尺寸变化的影响;(2)纤维体积含量影响了材料抗疲劳破坏的能力,疲劳寿命随着纤维体积百分含量的提高而延长;(3)疲劳寿命依赖于纤维强度Weibull分布中形状参数的变化,疲劳寿命随着形状参数的增大而延长;(4)疲劳寿命随着疲劳延性系数的增大而延长,但随着疲劳延性指数绝对值的增大而缩短。The effects of six kinds of influential parameters on fatigue life of continuous fiber-reinforced metal matrix composites were investigated by num mechanisms under cyclical thermomechanical loading erical simulation based upon micromechanical damage The results show that, （1） There is an obvious decrease in composite fatigue life as the specimen dimension increased.However the size effect on the fatigue life gets disappeared when the composite size is more than 25 fibers and its length is longer than 30 times fiber diameter. （2） Fiber volume fraction has great influence on fatigue life. When increasing fiber volume fraction, higher life is achieved. （3） The fatigue life of the composite strongly depends on the magnitude of shape parameter in Weibull distribution.As the scatter of the fiber tensile strength decreases the fatigue life of composites will dramatically increase. （4） The greater fatigue ductility coefficient is, the higher fatigue life is; however, the greater the absolute value of fatigue ductility exponent is, the lower fatigue life is.

关 键 词：金属基复合材料 热/机械疲劳寿命 MONTE-CARLO模拟 参数研究 

分 类 号：TB333[一般工业技术—材料科学与工程] O346.1[理学—固体力学]