带脱层复合材料层板的低速冲击响应

研究了含脱层损伤的复合材料层板在低速冲击下的瞬态响应问题。首先,用基于Mindlin板理论的有限元法来描述层板的运动和变形,并同时考虑了层板大变形的影响。另外,用一种修正的Hertzian压痕法则来计算层板和刚球间的冲击力。同时为了有效地处理脱层间的动态接触问题,采用了由笔者以前提出的一种修正的Lagrange multiplier乘子法来提高计算精度和效率;为了研究脱层的扩展机理,提出了一种基于Mindlin板模型的应变能释放率的计算方法,用于计算脱层前沿的应变能释放率的分布。最后,算例研究了刚球的初始冲击速度、脱层面积和脱层位置对计算结果的影响,算例中提供的信息为人们更好地理解脱层损伤的扩展机理和它对复合材料层板的低速冲击响应的影响提供了依据。

DELAMINATED COMPOSITE LAMINATES' RESPONSE UNDER LOW-VELOCITY IMPACT

The transient response of delaminated composite laminate under low-velocity is discussed in the present paper. At first, the Mindlin plate finite element is used to describe the movement and deformation of composite laminates with a circular delamination, in which large deformation is considered. Secondly, an improved Hertzian indentation law is used to calculate the contact force between the laminates and the rigid ball. To deal with the contact problem between delamination, we use an improved Lagrange multiplier method which was posed previously by the author. To explore delamination growth mechanism, we present a numerical method based on the Mindlin plate model to calculate the strain energy release rate at the front of a delamination. Finally, the influence of initial impact velocity, delamination area and delamination location is discussed. And the results of numerical examples provide a great deal of information for people to understand the delamination growth mechanism and its influence on the impact response of delaminated composite laminates.