Designing low noise engines is challenging due to the contrary demands of using lightweight materials while increasing the power of vehicles. AVL and SimuliaA are leveraging advances in substructure (‘superelement’) capabilities of Abaqus with AVL EXCITE to provide new functionality for powertrain noise and vibration analysis.

A engine model consists of various parts such as a crankshaft, connecting rods, and an engine cylinder block, coupled with nonlinear contact such as journal bearings. The mass/moment of inertia and elasticity of these bodies are included in Abaqus. This enables engineers to calculate powertran dynamics including hydrodynamic contact. A transient engine run-up simulation enables the full range of engine speed and loading condition to be investigated.

The noise and vibration analysis starts with the finite element (FE) models for engine components such as the crankshaft, connecting rod, and power unit. The first analysis is a natural frequency analysis using Abaqus. A static and dynamic condensation of the FE models provides reduced mass and stiffness matrices for the following nonlinear forced vibration calculation performed with AVL EXCITE. This step provides all motion quantities and structural vibrations for the entire FE model. This integrated process provides workflow efficiencies and improvements in simulation fidelity for powertrain noise and vibration analysis.

Dassault Systèmes Simulia Corp is based in Providence, RI, USA. www.simulia.com or www.avl.com