含预置分层层合板的分层扩展及其屈曲行为研究

发布时间：2018-05-04 14:26

本文选题：复合材料层合板 + 预置分层　；参考：《哈尔滨工业大学》2015年硕士论文

【摘要】：由于复合材料具有十分出色的材料性能,并且密度较小,因此在飞行器结构设计被大量使用。然而复合材料的屈曲分层及其分层扩展现象严重影响着复合材料结构的稳定性,因此对复合材料屈曲行为及其分层扩展的研究有着十分重要的意义。本文针对复合材料层合板设计了一系列的预置分层,包括不同分层位置、分层尺寸、分层大小以及分层数量等作为变量,设置预置分层,从而研究不同预置分层对层合板屈曲载荷、分层扩展及其疲劳寿命的影响。本文首先用PATRAN对含预置分层层合板进行数值模拟,得到其屈曲临界载荷,再取不同的的屈曲载荷的百分比加载,观察层合板的分层扩展趋势。然后再对无损伤层合板进行屈曲模拟,得到其屈曲临界载荷,与含预置分层层合板进行对比,分析其不同分层因素对复合材料层合板屈曲载荷和承载能力的影响。然后分别对无损伤复合材料层合板和含预置分层复合材料层合板进行压缩实验,得到其屈曲载荷,进行分析,再与数值模拟的结果进行对比分析。最后对含预置分层层合板进行疲劳实验,得到不同预置分层层合板的疲劳寿命次数,然后分析不同预置分层对层合板疲劳寿命的影响。从而得到如下结论:1、当预置分层尺寸、形状均相同时,预置分层距离层合板中心层越远,层合板承载能力下降越大,承载能力越弱。2、当预置分层位置、形状均相同时,预置分层的分层面积越大,层合板的承载能力下降越大,承载能力越弱。3、当预置分层尺寸、位置均相同时,预置分层为圆形的层合板比预置分层为矩形的层合板承载能力弱。4、预置分层的分层数目越多,层合板的承载能力下降越多,越容易发生屈曲。5、耦合预制分层中圆心位于试验件中心的圆形预置分层比预置分层位于边缘的矩形预置分层承载能力下降更多,更容易发生屈曲,从而破坏。6、预置分层层合板的扩展趋势为分层先沿着垂直加载方向进行扩展,然后再沿着平行加载方向进行扩展。7、含预置中央分层层合板的抗疲劳能力较强,对其施加80%屈曲载荷进行疲劳实验不容易引起它的分层扩展。含预置边缘分层层合板的抗疲劳能力较弱,对其施加80%屈曲载荷进行疲劳实验容易引起它的分层扩展。
[Abstract]:Because of its excellent material properties and low density, composite materials are widely used in aircraft structure design. However, the buckling delamination and delamination propagation of composites seriously affect the stability of composite structures, so it is of great significance to study the buckling behavior and delamination propagation of composites. In this paper, a series of preset delamination is designed for composite laminates, including different delamination position, delamination size, delamination size and number of delamination as variables. The effects of different pre-delamination on buckling load, delamination propagation and fatigue life of laminated plates are studied. In this paper, PATRAN is used to simulate the critical buckling load of laminated plates with preset layers, and then different percentages of buckling loads are taken to observe the delamination expansion trend of laminated plates. Then the critical buckling load of the laminated laminates without damage is simulated and compared with the laminated plates with prefabricated laminates. The effects of different delamination factors on the buckling load and load-carrying capacity of composite laminated plates are analyzed. Then the buckling load of the laminated laminates without damage and the laminated laminates with prefabricated laminates are analyzed and compared with the results of numerical simulation. Finally, the fatigue life times of different preset laminated laminates are obtained by fatigue experiments, and the influence of different preset layers on the fatigue life of laminated plates is analyzed. The following conclusion can be drawn as follows: 1. When the size and shape of the preset layer are homogeneous, the further the preset delamination is from the central layer of the laminate, the greater the load capacity of the laminated plate is, and the weaker the load-carrying capacity of the laminated plate is, when the preset delamination position is at the same time, the shape is homogeneous at the same time. The larger the stratification area is, the greater the load capacity of laminates decreases, and the weaker the bearing capacity is. 3. When the size of the preset layering is equal, the position of the laminated laminates is homogeneous at the same time. The load-carrying capacity of laminated plates with circular prelayed layers is weaker than that of rectangular laminated plates. The larger the number of layers, the more the load-carrying capacity of laminated plates decreases. The more prone to buckling. 5, in the coupled prefabricated delamination, the load capacity of the circular preset delamination located at the center of the test piece is much lower than that of the rectangular preset delamination at the edge of the preset delamination, and the buckling is more likely to occur. As a result, the expansion trend of prefabricated laminated laminates is that the delamination extends first along the vertical loading direction and then along the parallel loading direction. The fatigue resistance of the preset central laminated laminates is stronger. The fatigue test of 80% buckling load does not easily lead to its delamination propagation. The fatigue resistance of laminated laminated plates with preset edges is weak, and the fatigue test of the laminated plates with 80% buckling load will lead to its delamination expansion.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB33

【引证文献】