Numerical and Experimental Investigation of Aluminum/CFRP Hybrid Tubes with Rubber-like Interlayer

In the automotive, aerospace, printing, and sports industries, the development of hybrid CFRP-metal components is becoming increasingly important and used. The coupling of metal with CFRP, in axial symmetric components, results in reduced production costs and an increase in mechanical properties such as bending, torsional stiffness, mass reduction, and critical speed, when compared to the single material-built ones. The challenge for engineers is to design hybrid co-cured tubes with external metal layers, which avoid possible detachments and delaminations due to the mismatching coefficients of thermal expansion of the two materials. In this work, residual thermal stresses and strain have been studied with numerical models based on Finite Element Method (FEM) and compared with experimental tests. The FEM model allowed for the investigation of the influence of length, diameters, thickness and interface layer material on residual thermal stress peaks near the free edges zone. To reduce the risk of premature failure,the interleaving of a rubber-like layer is proposed and experimentally validated.