湿热环境对航空复合材料加筋板压缩屈曲和后屈曲性能的影响

Influence of Hygrothermal Environment on Compressive Buckling and Post-buckling Performance of Aero Composite Stiffened Panel

使航空复合材料加筋板在湿热环境中(70°C、水浴)达到吸湿饱和状态,对普通加筋板(A型)和吸湿饱和加筋板(B型)进行压缩实验。两类加筋板的破坏形貌相似,主要是筋条的断裂、脱粘和壁板的分层、撕裂,但破坏位置显著不同,A型加筋板的破坏位置均在加筋板中部附近,而B型分别在靠近两端的部位破坏,表明B型加筋板的破坏位置具有不确定性。两类加筋板的屈曲形式均为筋条间壁板的屈曲和中间2根筋条的屈曲,但两类加筋板相同位置的失稳壁板的弯曲方向相反,说明湿热环境对失稳壁板的弯曲方向影响较大。B型加筋板在压缩载荷下仍存在后屈曲过程,湿热环境对加筋板的屈曲载荷影响较小,对破坏载荷影响较大,较A型加筋板相比两者分别下降了3.1%和22.2%。

Aero composite stiffened panel achieved absorbing moisture saturation in hygrothermal envi- ronment （70℃ distilled water）. The compressive experiments were conducted on the untreated composite stiffened panels（type A） and the saturated ones（type B）. Failure modes of the both types stiff- ened panels are similar with three major ways, including fracture and debonding of stiffeners together with the splitting and ripping of the panels. The fracture locations of type A are around the middle of panels while those of type B are towards either end of the panels, indicating the uncertainty of fracture locations for type B. The buckling patterns for both types are buckling of panels between stiffeners and buckling of the two middle stiffeners. The bending direction of type B is opposite to that of type A in the panel of same position, showing hygrothermal environment imposes much effect on the bending direction of panels. There still exists a post-buckling process for type B under compression, showing hygrothermal environment has less effect on the buckling load and more effect on the failure load of panels, whose buckling load and failure load decrease by 3.1% and 22.2%, respectively, compared with those of type A.