To study the effect of low velocity impacts on composite material buy using Finite element analysis software LSDYNA

Abstract

During the life of a structure impact by foreign objects can be expected to occur during manufacturing, service and maintenance operations. An example of in service impact occurs during aircrafts takeoffs and landing. During the manufacturing process or during maintenance tools can be dropped on the structure, in this case the impact energy is small, laminated structures are more susceptible to impact damage often cannot be detected by visual inspection. This internal damage can severe reductions in strength and further reductions occur under the load. Therefore the effects of foreign object impact on composite structure must be understood and proper measures should be taken in the design process to account for expected events. Concerns about the effects of impact on the performance of composite structures have been a factor in limiting the use of composite materials. For these reasons the problem of impact has received considerable attention in the literature. The process of impact damage initiation and growth, and identify the governing parameters are important for the formulation of numerical models for damage prediction, for designing impact resistant structures and for developing improved material systems. An important aspect of a model for predicting the impact dynamics is to accurately describe the behavior of the target under impact loading conditions. For some simple cases the structural loading can be modeled by a simple spring-mass system or by using the quasi-static behavior and considering the energy balance for a system. But in general more sophisticated beam, plate or shell theories are required to model the structure.