Managing System Effects of Traction Bars Implemented on a Hotchkiss Suspension

This paper describes the implementation effort behind adding a pair of suspension links between the axle and frame of a light truck with a Hotchkiss-type suspension. These links, referred to as anti-windup bars (or traction bars), were introduced into an existing system to improve NVH performance; however, doing so required modifications to maintain other vehicle attributes, including vehicle safety and durability life. The authors address the management of these attributes and related design decisions for the components involved, focusing on the conflicting requirements involved. Physical vehicle testing, using design revisions recommended by Finite Element (FE) simulations, was performed to confirm component performance and related system behavior. Test results suggested improvements to the FE models that were required to more closely approximate the vehicle's behavior. Several of these FE model improvements and component design iterations were implemented simultaneously, resulting in effective anti-windup bar and frame structure design revisions. These design revisions improved the system's ability to manage the energy inputs to the system during vehicle durability and crash testing.