二维编织复合材料圆柱曲板屈曲性能试验与有限元分析

Test and finite element analysis of buckling performance for 2D textile composite cylindrical curved panels

采用试验和数值模拟方法研究了二维编织复合材料曲板的屈曲性能。为研究曲率半径、长度以及弧长等参数对二维编织复合材料曲板屈曲性能的影响,设计了4组不同曲率半径、长度以及弧长的曲板进行屈曲试验。通过对比4组不同几何尺寸曲板的屈曲载荷与屈曲模态,发现曲率半径减小25%,相应的屈曲载荷增大26.85%,影响最大;弧长增大26.32%,单位面积的屈曲载荷基本不变,屈曲载荷增大23.783%;长度减小42.25%,屈曲载荷提高24.41%。长度对屈曲模态的影响最大,弧长影响次之,曲率半径影响最小。设计相应材料的ASTM标准试验获取材料刚度系数,基于曲板弧形边在飞机结构和试验过程中存在安装和摩擦等影响而存在一定约束,进行曲板四边沿弧线方向存在约束和不存在约束两种简支条件下的屈曲有限元分析。通过试验与有限元的对比,在两种边界条件下模拟载荷能很好地确定试验屈曲载荷的范围。

Test and numerical simulations were adopted to study buckling properties of 2Dtextile composite curved panels.In order to study the influence of curvature radius,length and arc length on buckling properties of 2Dtextile composite curved panels,four groups of specimens with different curvature radius,length and arc length have been designed to conduct buckling test.Comparing the buckling load and buckling mode of four different groups of curved panels,the influences of different geometric parameters on buckling properties have been acquired.The buckling load rises by 26.85%as the curvature radius decreases 25%,which exert the most important influence.As with the26.32% increase of arc length,the buckling load per area keeps equal generally and buckling load increases23.783%.The buckling load increases by 24.41%,while the length decreases by 42.25%.As to buckling mode,length affects most,arc length ranks second,and curvature radius follows.A standard test referring to ASTM was designed to acquire material stiffness coefficient.As the arc sides of curved plates were quite constrained as a result of fixing and friction in aerocraft structure and test,buckling finite element analysis under two types of boundary conditions,with and without constraints were conducted.Through the comparison of test and finite element result,simulated load under two boundary conditions can determine the scope of the test buckling load.