Evaluating the Reliability of Glass-Braid-Reinforced Polymer Composite Coil Spring for Automotive Suspension Development Using Finite Element Method and Empirical Tests

This study conducted a comprehensive assessment of the reliability of automobile glass-braid-reinforced polymer (GBRP) composite coil springs fabricated using a braiding technique. The evaluations encompassed durability, plastic deformation, and resistance to chipping, adhering to the industrial standards established for steel springs within the automobile industry. In addition, a method to evaluate the void distribution and impregnation rate is proposed to quantitatively evaluate the quality of the composite fabrication. A method for testing part of manufactured springs was developed using finite element analysis, and the validity of this testing method was confirmed through empirical testing. Upon completing the durability and plastic deformation examinations, the changes in the free height of the GBRP composite coil springs exceeded those of their steel counterparts by 47% and 162.5%, respectively. Notably, these tests revealed no discernible surface failures or fractures on the composite springs. To elucidate the changes in free height observed post-testing, scanning electron microscopy was employed to assess the incurred damage. Furthermore, results from the chipping resistance tests substantiated that the GBRP composite's safety attributes were not compromised by any surface damage.