An ultra-lightweight CFRP beam-string structure

In this work, an ultra-lightweight beam string structure made of carbon fiber reinforced polymer (CFRP) composites was designed, optimized, fabricated and tested. ANSYS APDL was adopted to optimize the design of the structure. A four-point bending test was carried out to investigate the structural behavior. Despite of being a non-full-scale structure, an exceptionally high structural efficiency, 56 N/g, was successfully achieved. Additionally, finite element analysis was conducted to investigate the effect of prestressing force in tension string. The added prestressing was identified to be able to increase the flexural strength of the structure by up to 15%. Moreover, with the thickened tension string, for instance for the 2.0-mm-thick string, 3% prestressing was able to provide a significant increase of the flexural strength and stiffness by up to 28% and 115%, respectively. The increased flexural strength was attributed to the improved stress distribution of compression beam. The proposed CFRP beam string structure, having an ultra-lightweight and a high load-carrying capacity, has a great potential to be widely adopted in conceptual developments and practical applications, particularly when high structural efficiency is required.