基于四点弯曲试验的复合材料R区层间性能研究OA

In aircraft structural design practice,the R-zone is a key detail prone to generating out-of-plane in-terlaminar tensile stress.Based on the four-point bending test method,this paper designed an impact scheme to intro-duce barely visible impact damage(BVID)and obtain the influence of damage type,part thickness and environment type on the interlaminar tensile strength of R-zone under the damage condition.For the configuration presented in this paper,when the size of the defect is 15 mm×7 mm,the direction of the defect placement has little influence on the interlaminar tensile strength.For the 3.42 mm thick test specimens studied in this paper,BVID causes a higher re-duction in interlaminar tensile strength compared with manufacturing defects.For the test samples with different thick-nesses,the interlaminar tensile strength is related to the thickness.The high temperature and wet environment has a certain influence on the interlaminar tensile strength,and the reduction coefficient in this paper is 0.38.The conclu-sions and rules of this paper can be used for guidance and reference in engineering application.