Experimental Study of Low Speed Impact Test on the Fiber-Metal Composite Toughened with NBR Elastomer

In this experimental study, low velocity impact test with different energy levels was performed on a fiber-metal (FML) structure reinforced with NBR elastomer. The FML structure consisted of a 2024 layer of aluminum as the core, two layers of NBR elastomer on both sides of the aluminum, and a composite layer after the NBR layers, which were made by hand layup method. The composite layers were made of bi-direction carbon fiber fabric as well as phenolic resin. Also, the knocker was made from very high hardness and hit the FML sample with various energy levels (50, 58, and 66 joules). Thus, the present paper studied the effect of different composite thicknesses on the front and back of the core against the three impact energies. One of the notable innovations in this work is the use of NBR elastomer, which acts as a reinforcement in withstanding impact loads. Based on the obtained results, the maximum and minimum amount of contact force absorbed energy, deformation, and contact time was related to P ... 2.2 and P … 1.1 samples. By comparing the P … 2.1 and P… 1.2 samples after the impact test, it was shown that P… 2.1 samples had a softer behavior.