Damage Analysis Of Composite Overwrapped Pressure Vessels Under Low Velocity Impact

Fiber reinforced polymer composites have been used widely in many applications such as aerospace, pressure vessels, automobile parts and sport equipments due to their high specific strength, high specific stiffness and specific energy absorption. Composite overwrapped pressure vessels (COPV) are among the most effective solutions for high pressure storage of compressible liquid and gaseous fluids. However, it is well known that they are susceptible to damage resulting from lateral impact by foreign objects. Impact-induced damage may arise during manufacture, maintenance and service operation. Low velocity impact could cause significant damage, in terms of matrix cracking, fiber fracture, delamination, and so on. Such damage is very difficult to detect by naked eye and can lead to severe reductions in the stiffness and strength of the COPV. So the safety states of COPV are very important for personal belongings safety. As the impact damage depends not only on the material properties but also on the dynamic behavior of the impacted structure, it is very important to have a more recognition of the structural response under impact as well as how it is affected by many other different parameters.This paper analyses the damage of COPV under low velocity impact based on the commercial software MSC.SimXpert/MD Explicit. The author employs the [Chang and Chang,1987] damage criterion and stiffness reduction criterion to determine the modeling of the gradual failure process. The parameters such as impact energy, internal pressure of COPV and impact position can also affect the impact resistance of COPV under impact. At the same time, the paper performs drop test simulation to predict impact-resistance properties of COPV. The purpose of this paper is to predict the damage characteristic of the filament wound layers and the most dangerous position of COPV under low velocity impact. By analysing the damage characteristic of COPV, it’s useful to the physical design and protection design of COPV under low velocity impact. It can shorten the development cycle of COPV and cut major personnel and property losses caused by the damage.