INVESTIGATION OF THE COMPOSITE BEAM BEHAVIOR SUBJECTED TO IMPACT FATIGUE LOADING

Abstract

The objective of this research is to investigate the effect of repeated low-velocity impacts experimentally on composite materials in which two types of laminated composite beams are used (2D and 3D woven fabric/lamination (80:20) resin) under repeated impact tests. The tests were performed and exposed to repeat low-velocity impacts (1.4 m/s) for all tests by using an impact fatigue apparatus that is designed and manufactured. The effect of repeated impacts is studied on peak load, a number of laminate, and drop masses with respect to a number of cycles under gravity fall. A comparison is made between 2D & 3D samples for all layers of composite materials. Results show that the mechanical properties of all specimens decrease with an increase in the number of impacts per unit time, experimental results also show that the 3D samples have more resistance to impact damage than 2D samples so that samples of 3D five layers are stronger and they have longer lifetime fatigue from 2D six layers samples. The comparison between 2D-6 layers and 3D-5 layers appeared that 3D-5 layers are more efficient and more resistant to impact where the increase in lifetime percentage at energy 12.63J, 7.13J, 4.69J, and 3.36J were 100%, 64%, 42%, and 37%. The stiffness of 2D & 3D laminate composite beams is reduced by 30% when the samples are a failure.