A clamped-beam bending test method for the flexural behaviour of uncured metal-CFRP laminates

This paper examines the flexural behaviour of uncured metal-carbon fibre reinforced polymer (CFRP) laminates when subjected to clamped-beam bending conditions. The test method was developed to assess how clamping affects the ratio between stretching and drawing during a proposed press forming process. The study compared the effects of variations in metal composition, layup, fibre orientation, and processing temperature on bending force, spring-back depth, and sliding length. The results revealed that increasing clamping pressure from 0 bar to 6 bar for aluminium-based hybrid materials with a 2/1 layup decreased the interlaminar sliding length by 3%, resulting in a rise in plastic strain in the metal layer from 2.55% to 15.22% and a reduction in spring-back by 10%. Additionally, the maximum bending forces for the uncured 2/1 metal-CFRP laminates were found to be slightly higher than twice that of the corresponding single-layer metal sheets. The processing temperature, ranging from room temperature to 110°C, was also shown to affect the bendability of the laminate, particularly at a clamping pressure of 0 bar. Furthermore, both numerical and experimental results demonstrated a strong correlation at room temperature across various clamping pressures for the hybrid materials studied.