Virtual Verification of Wrecker Tow Requirements 2020-01-0766

Under various real-world scenarios, vehicles can become disabled and require towing. OEMs allow a few options for vehicle wrecker towing that include wheel lift tow using a stinger or towing on a flatbed. These methods entail multiple loading events that need to be assessed for damage to the towed vehicle. OEMs have several testing and evaluation methods in place for those scenarios with majority requiring physical vehicle prototypes. Recent focus to reduce product development time and cost has replaced the need for prototype testing with analytical verification methods. In this paper, the CAE method involving multibody dynamic simulation (MBDS) as well as finite element analysis (FEA) of vehicle flatbed operation, winching onto a flatbed, and stinger-pull towing are discussed. The simulations evaluate and address events such as bumper and underbody parts clearance to the ground, subframe impact with the stinger arm, chain loading on the body, as well as winch cable contact with underbody parts. MBD-FEA co-simulations is an option, but it may not work well when the design process involves disjoint teams, including suppliers. Hence, a systems engineering approach was chosen in order to decouple the MBS and FEA efforts. This enables the CAE method to be more general and allows for system-independent design of various components and parts independently by suppliers. It also reduces the design iterations between the supplier and OEM by providing the design space for the components in the engineering specification documents. Several simulation results for vehicle winching, flatbed operation, and stinger pull, using MSC ADAMS and Abaqus, are presented to demonstrate the effectiveness of the approach.