Sudden bending of a cracked laminate

Abstract

A number of laminated plate theories have been developed in recent times to analyze the static and dynamic response of composite laminates with or without the presence of stress concentrators such as holes, cracks, etc. Many of the theories tend to quickly become intractable when considering the determination of the state of affairs near the singular crack edges that are present in the laminate, particularly if the loading is time dependent. Additional uncertainties arise due to the lack of information on the mechanical properties of the interface through which load transfer takes place between the adjacent layers. This paper focuses attention on the intensification of stresses near a through crack in the laminate that suddenly undergoes bending. A dynamic plate theory is developed to include many of the essential features of the problem such as material nonhomogeneity in the thickness direction, realistic crack edge stress singularity and distribution while the parameter dependence of various significant quantities is also assessed. Of particular interest is the variation of the dynamic stress intensity factor with time. Numerical results for different geometric and material constants are displayed graphically to show how they can affect the transfer of load to the vicinity of a through crack in the laminate that undergoes sudden bending.