Durability is an important indicator to measure the automobile quality and reliability. Automotive industry is striving to develop products having excellent performance to weight ratios and along with high safety standards. A successful product should have adequate robustness during normal customer operation and the ability to withstand high impact events without impairment of function or safety relevant damage. Road Load Data Acquisition (RLDA) along with efficient design and validation processes are, among others, critical factors for success in the automotive industry.
Physical RLDA is expensive and time consuming, the prototype vehicles being costly and only available at a later stage in the vehicle development cycle. Component failures occurring on the proto test vehicles can prove to be a major setback, delaying the product launch by months. In order to overcome above challenge, this paper presents an innovative methodology to carry out Digital RLDA (dRLDA).
The methodology consists of development of high-fidelity digital vehicle model and digital torture tracks using frugal approach. Digital vehicle is based on mixed rigid-flexible bodies approach to accurately capture the load transfer paths and includes F-tire based tire models to capture high frequency, low wavelength excitations. This vehicle model has been validated against Kinematics & Compliance (K&C) measurement data. Digital tracks are developed using a hybrid technique, to convert 3D CAD into digital data for creation of digital tracks. Developed digital vehicle model is run on digital tracks to capture the loads, strains, accelerations, displacements etc. on vehicle components using virtual sensors.
dRLDA methodology is validated with two case studies: 1) Wheel hub loads, 2) Engine mount loads. The results suggest data obtained by dRLDA is in good agreement with physical RLDA data and the proposed methodology can be deployed for automotive durability analysis. The dRLDA methodology has tremendous potential to compress the product development timeline. It will also reduce the vehicle development cost due to reduction in number of prototype vehicles required as well as the reduction in physical testing itself. dRLDA will enable the engineers to strive for ‘First Time Right’ design and allow for quick assessment of design changes.