聚四氟乙烯网格状人工缺陷对复合材料胶结结构力学性能的影响  

Effect of PTFE Grid Artificial Defects on the Mechanical Behavior of Composite Joints

作　　者：林木烟 张婷 王欢 彭华新 LIN Muyan;ZHANG Ting;WANG Huan;PENG Huaxin(School of Materials Science and Engineering,Zhejiang University,Hangzhou 310027,China;Department of Discipline Engineering,AECC Commercial Aircraft Engine Co.,Ltd.,Shanghai 200241,China)

机构地区：[1]浙江大学材料科学与工程学院,浙江杭州310027 [2]中国航发商用航空发动机有限责任公司设计研发中心,上海200241

出　　处：《材料科学与工程学报》2024年第2期193-199,共7页Journal of Materials Science and Engineering

基　　金：科技部国家重点研发计划资助项目(2022YFB3709100);国家自然科学基金联合基金资助项目(U2133213)。

摘　　要：通过在胶接接头界面处插入网格状的聚四氟乙烯(PTFE)薄膜作为人工缺陷,设计了5种不同PTFE缺陷网格含量(P)的复合材料胶接结构,采用工业CT和超声C扫的无损检测(NDT)手段对置入的PTFE网格进行检测,利用单搭接测试(SLJ)和Ⅰ型断裂韧性测试(DCB)进行力学性能表征。相比于超声C扫,工业CT可以清晰检测出置入的PTFE网格。SLJ结果表明,当P值低于10%时,胶接接头的剪切强度从13.85 MPa增加到15.15 MPa;当P值超过10%时,剪切强度随缺陷值增加而下降。SLJ胶接接头破坏形貌表明,随缺陷值的增加,失效模式从内聚失效转向混合失效,最后变成界面失效。DCB结果表明,G_(IC)随缺陷值增加呈现先升后降趋势,裂纹扩展状态从近稳定连续转向“粘-滑”的不稳定扩展。Five kinds of composite bonding joints with different grid contents(P)were designed by embedding polytetrafluoroethylene(PTFE)grids into the bonding interface as artificial defects.The computed tomography(CT)and ultrasonic C-scan are the nondestructive testing(NDT)methods used to examine the embedding grids.The mechanical performance was characterized by single-lap joints(SLJ)test and double cantilever beam(DCB)test.Comparing to C-scan,the embedded PTFE grids with different P contents could be detected clearly by CT.The SLJ result showed that the shear strength of the joints increased from 13.85 MPa to 15.15 MPa,when the P content was less than 10%.When the P content was higher than 10%,the shear strength decreased with increasing P values.The damage morphology of SLJ adhesive joints had a transition from cohesive failure to a mixed failure,and final an interfacial failure mode with the increase of P.With the increase of P,on the one hand,the G_(IC) value increased initially,followed by a decrease.On the other hand,the crack propagation changed from a stable and continuous condition to an unstable and“stick-slip”state.

关 键 词：胶接结构 PTFE网格 单搭接剪切 Ⅰ型断裂韧性 

分 类 号：TB333[一般工业技术—材料科学与工程]