Simulation of Endurance and Thermo Cycle Testing for Highly Loaded HSDI Diesel Cylinder Heads

Due to today's demands to reduce cost and product time to market, engineering procedures are increasingly using more sophisticated simulation techniques, instead of validation testing. Early implementation of CAE methods yield higher quality products, even with first prototypes, reducing the design iterations required to reach production quality. The strategy is to conduct specific evaluations of a realistic representation of the product while focusing on the key boundary conditions necessary to extract fatigue effects. Discussed in this paper are adequate CAE methods for early identification, evaluation and removal of conceptual and local structural weaknesses. Possible solutions gained from a computational optimization process are discussed for highly loaded HSDI diesel cylinder heads as a representative example.

Preloading conditions representing the manufacturing process (residual stresses due to the mold process respectively heat treatment and machining) and assembly loads (press fits, bolting) are superimposed with operation loads (temperature distribution, gas loads) in all non-linear FEA, applying the latest commercial ABAQUS^® FE-solver. Subsequently performed simulations like thermo-shock and durability testing underline the high influence of the load history and single load collectives on operational safety and life-span.