Metallic Inserts in Hybrid Composite Structures
The automotive industry is increasingly seeking lightweight composite parts that can be efficiently mass-produced. However, traditional continuous fiber composites are costly, while Sheet Moulding Compound (SMC) parts exhibit significant variability. To bridge this gap, hybrid composites combining Uni-directional (UD) Tapes and SMC offer a promising solution. In this context, a suspension arm for a multi-link suspension system serves as the target part for our project. By molding complex I-beams with a similar cross-section to the suspension arm using hybrid composites, we aim to enhance the net tensile strength of the component. To further optimize the design, six inserts are incorporated into the hybrid I-beams to reduce stress concentration and improve bearing strength. Through pin-bearing tests, we assess the influence of insert shape, projected area, and texture on the performance of the parts. The resulting hybrid parts exhibit superior strength compared to aluminum, albeit with slightly lower stiffness.
Bearing Test Samples
Tested Samples for Knurled and Yo-Yo Insert
Predicted vs Tested Results
This report delves into the investigation of variables influencing bearing load introduction in hybrid composites. The study focuses on two key variables: UD placement and insert design. Complex I-sections were compression molded using SMC and UD-SMC hybrid composites, incorporating novel inserts, and subsequently subjected to pin-bearing tests. The conclusions drawn from the molding process highlight the need to account for SMC springback, using solvents for UD adhesion, and employing UD tapering in all directions. In terms of design, placing UD strips around the hole in hybrid composites effectively harnesses the high tensile strength of UDs and the high bearing strength of SMCs. Hybrid composites achieved a remarkable over 200% increase in tensile strength with less than 7% UD content. Knurled inserts further improved performance by 60% through enhanced grip on the SMC. The study also emphasizes the importance of insert location and the critical role of width/diameter ratio.