The present study details the design evolution and failure analysis of a novel hybrid stabilizer bar link (stab link) developed for the front suspension of a born electric sports utility vehicle (SUV) platform characterized by higher gross vehicle weight (GVW), increased wheel travel, and constrained packaging space. To address these challenges, a unique hybrid stab link was designed featuring dual plastic housings at both the metal ball joint ends, connected by a steel tube, and achieving a 30% weight reduction while offering enhanced articulation angles for extremely lower turning circle diameter (TCD) of the vehicle, compared to the conventional stab link. The unique hybrid stab failed under complex loading conditions during accelerated durability testing (ADT), prompting a comprehensive investigation. The failure analysis included road load data acquisition across various stab bar diameter configurations evolved during suspension tuning, different stabilizer link designs evolved during the design stages, comparative load assessments on different road patches, simulation of failure scenarios on test rigs, and extensive material testing. Investigation techniques such as fishbone diagram, destructive testing, part quality and dimensional accuracy evaluation, mechanical property evaluation, chemical composition analysis, metallography, and microscopic examination were employed. Results confirmed that the mechanical and chemical properties of the stab link met the design specifications. The comprehensive failure analysis was concluded by attributing to fatigue fracture caused by excessive loading of the stab link. This paper introduces a unique methodology for hybrid link design optimization that considers real-world loading conditions such as higher equivalent ADT block cycle during the hybrid stab link development process. The study concludes with insights into the iterative design enhancements and investigative procedures that led to improved durability and performance of the stab link assembly, offering a significant advancement over conventional stab link designs.
Key words: Hybrid stab link, Higher articulation, Less weight, MacPherson strut, ADT test, RLDA, failure investigation, Fish bone diagram.