密封舱结构裂纹扩展敏感性分析研究

Research on Sensibility of Crack Growth in Sealed Capsule

针对密封舱结构中的裂纹的起裂和疲劳扩展问题,基于疲劳裂纹扩展理论,借助n Soft软件,在结构不同位置设置不同尺寸的初始裂纹,分析了初始裂纹以及壁板主要参数如加强筋高、加强筋厚度、加强筋间距对裂纹扩展的影响。结果发现:初始裂纹尺寸或应力增大都会导致裂纹扩展更严重;裂纹扩展对筋间距很敏感,平板区随着间距的增大更难发生裂纹扩展;内部筋底和外部筋底的裂纹扩展对筋高度比较敏感,对平板区域无影响;外部筋底的裂纹扩展对筋厚度较敏感,筋厚度增大会导致裂纹扩展更易发生。

To solve the crack initiation and fatigue expansion problems in the structure of the sealed capsule, nSoft software was used to set initial cracks with different sizes in different positions of the structure according to the fatigue expansion theory. The influences of initial cracks and the main pa-rameters of wallboard such as the height, thickness and spacing of the reinforcement on the crack propagation were analyzed. The results showed that the crack growth became more serious with the increase of the initial crack size and stress. The crack propagation was sensitive to the spacing of the reinforcements, and the crack propagation in the flat area was more difficult to occur with the in-crease of the spacing. The crack propagation of the inner and external reinforcement at the bottom was more sensitive to the height of the reinforcement, and the crack in the flat area was not affected. The cracks in the external reinforcement at the bottom was sensitive to the thickness of reinforce-ment , and the increase of reinforcement thickness could more easily lead to crack propagation.