Experimental study on fiber reinforced polymer strengthened aluminum tubes under bending

Abstract: Aluminum alloy has the similar characteristics to CFRP (carbon fiber reinforced polymer) for structural application, including light-weighted, anti-corrosive and easy-shaped properties. However, strength and module of aluminum alloy are relatively low, and CFRP is anisotropic and easy to fail in connection parts. Combining these two materials into composite structural elements can compensate each other to fully exploit of their favorable properties. It was proposed that CFRP be used to strengthen aluminum alloy elements to improve performance. In this paper, two sets of specimens, including two pure aluminum tubes and four strengthened aluminum tubes processed by the vacuum bag aided processing procedures, are tested in four-point bending. Flexural stiffness and load capacity of the tubes with different CFRP layers and cross sections are investigated. It is shown that the flexural stiffness and the load capacity can be significantly enhanced with increasing amount of CFRP. The test results show that CFRP strengthened aluminum elements is a competent alternative for future long-span structures