Design and Numerical Evaluation of Recycled-Carbon-Fiber-Reinforced Polymer/Metal Hybrid Engine Cradle Concepts

The design and evaluation of polymer-metal hybrid (PMH) engine cradles are realized via the design of concept models and finite element (FE) analyses. The structures consider a low-cost recycled carbon fiber (rCF) and PMH technologies. The initial conceptual design consists of creating C-type/hollow-type inserts and modifying the plastic components by considering the dimensions and thickness of insert and inclusion of plastic ribs as the design parameters. The PMH engine cradles are then evaluated by performance criteria, including weight reduction, stiffness, natural frequency and strength. The integration of rCF with injection-molding over metal inserts promoted weight reduction. The hollow-type and C-type PMH engine cradles achieved the weight reduction of 19 and 16% compared to the reference steel engine cradle, respectively, while they fulfilled the evaluation criteria. The results contribute to the advance of lightweight engine cradles with improved structural performance, fabricated with low-cost carbon fiber and fast manufacturing processes.