At the manufacturing and chemical industries, the storage tanks have exploded frequently. The large and small accidents such as stress corrosion cracking, poor heat treatment, and rupture accidents happen at the fuel pipe in a vehicle. As part of an effort to reduce the damage these damage, rather than using only single materials, the complex material is constructed by bonding different materials that can complement the durability and rigidity of single materials. PVC, SUS304, and carbon fiber reinforced plastic (CFRP) which have been used in the overall industry. By adopting a heterogeneous material bonded by a sandwich method, the tensile and three-point bending tests were carried out with SUS304 and PVC as the outer materials and CFRP as the core material. The specimens with notch were manufactured in order to investigate the stress states shown at actual several tubes.
In this paper, an abbreviation on the specimen composed of PVC, CFRP and PVC is called by PCP. In cases of the stress concentration factors and the maximum stresses of single materials, the stress concentration factor of PCP was 54.7% higher than that of SUS304, and the maximum stress was increased by 321.3% by comparing with that of PVC.
The specimen composed of SUS304, CFRP and SUS304 is also called by SCS. The stress concentration coefficient of SCS was lower than that of CFRP or PVC, but the maximum stress was increased by 1,008.06% as compared with PVC. When the bending moment was applied on the specimens for three-point bending test, the breaking strength and the deformation were measured and compared with the single materials.
And the specimen composed of PVC, CFRP and PVC is called by PCP. As compared with the maximum bending stresses of single materials, the maximum bending stress of PCP is better than that of CFRP or SUS304. So, PCP can be advantageous as its rigidity increases as much as 122.8% than PVC.
The specimen composed of SUS304, CFRP and SUS304 is called by SCS. As compared with the maximum bending stresses of single materials, the maximum bending stress of SCS is lower than that of CFRP or SUS304. Therefore, the experimental results are different by depending on the loading direction through tensile and three-point bending test. Through the result of this study, the strength and stiffness of composite can be remarkably increased by depending on the its composition. It is thought that this study result is thought to become the useful contribution at the actual design by composing the composite materials from existing materials instead of new materials.