Application of fibre composites in a spindle ram design

When compared to steel or cast iron, carbon fibre composites offer excellent tensile and bending stiffness together with significantly smaller density. Research at the Research centre of Manufacturing Technologies in Prague has been aimed at the application of composite materials in structural parts design. Case studies on spindle rams were performed focusing on the design of experimental composite spindle rams and their benchmarking with reference steel components. The cross-section of both parts was 350x350mm and the length was 1200mm. The first design was made as a thick-walled composite body with a minimal amount of steel. The goal was to achieve static stiffness comparable to a reference steel component of the same size. The second design was manufactured as a hybrid structure composed of fibre composites with cork layers and bonded steel reinforcements. The goal was to improve damping of the structural parts in comparison with the steel components. Results of stiffness and modal properties were obtained from experiments and also using FEA. Experimentally obtained damping ratios of composite and reference steel rams were compared with and without the effect of connection interfaces on damping.