Dynamic Strength Co-Simulation for Valve Train Mechanism Design Virtual Validation 2020-01-0949

As the automotive market is very dynamic and vehicle manufactures try to reduce the vehicle development cycle time, more focus is being given to CAE simulation technologies to reduce the design cycle time and number of physical tests. CAE engineers are continuously working on improving the accuracy of CAE simulation, such as using flexible body dynamic simulation in place of linear static analysis. Strength calculation under dynamic condition is more accurate as compared to static condition as it gives more clear understanding of stress variation with motion, contacts and mass inertia.

Failure has been observed in new development of valve train pivot screw under test conditions. As per linear static analysis, design was judged OK. Normal linear static analysis is a two stage process. In first stage loads are calculated by hand or peak loads are taken from multibody dynamics (MBD) rigid body analysis. In second stage, stress calculation is carried out for peak load in quasi-static condition using finite element analysis (FEA). To investigate the reason of failure and prediction of stress in new proto part, flexible MBD stress analysis is carried out using ADAMS and Nastran software. Under co-simulation approach load extraction and stress calculation is carried out simultaneously. Dynamic simulation model consists of both flexible and rigid links. Using co-simulation process faster and more accurate transient stress analysis is carried out taking the advantage of both MBD and FEA approach.

This paper will present the methodology of CAE process for dynamic strength co-simulation by establishing the correlation of FEA and test results for failure investigation of valve train pivot screw. Using the new CAE process, further design optimization were carried out by validating different designs initially through simulation and final design through physical testing. Optimized design smoothly passed the required testing criteria.