Multi Body Dynamics Based Method for Twist Beam Cross Articulations Evaluation in Realistic Hilly Area Scenarios 2019-26-0251
Twist beam is a semi-independent suspension having two trailing arms attached to the chassis via rubber bushes. Closed profile ‘V’ shaped cross beam interconnects left and right side arms. It provides roll stiffness of the suspension, by twisting as the two wheels moves relative to each other. Due to driving and road conditions twist beam structures are subjected to cyclic twist loads resulting into roll fatigue failure mode. To design Twist beam for mass, package and performance it is required to find realistic cross articulations based on vehicle application, usage pattern and protect twist beam from roll fatigue failure mode. The objective of this paper is to develop a virtual method using ‘ADAMS ®’ multi body dynamics software for maximum relative wheel center displacements during realistic hilly areas conditions.
This paper describes half and full vehicle based virtual approach for twist beam cross articulations in hilly area conditions. Twist beam is modeled as a flexible body using Finite Element method considering it’s torsional and bending stiffness. The study shows twist beam subjects to more cross articulations in hilly area roads with potholes rather than on flat road. A realistic hilly area virtual 3D road with banking and curvatures with typical obstacle dimensions has been build using Adams software. Different scenarios like vehicle moving uphill, downhill with obstacles have been simulated using ‘Ftire’ 3D nonlinear tire model. Virtual results have been validated on vehicle by instrumenting and running over hilly area regions. The advantage of this study is to represent realistic simulation scenario and finding out maximum cross articulations for twist beam design. The conclusion is helpful for designing twist beam cross articulations spectrum for accelerated durability test of twist beam structures. Also, helpful for robust design of twist beam suspensions in the early stage of the vehicle development program.
Prajakta Omkar Khare, Tej Pratap Prasad