SIMULIA's blog

The uniform pressure method (UPM) approach to simulat-ing airbag deployment has been widely used in the auto-mobile safety industry. The defining assumption of UPM, specifically that pressure in the airbag is spatially uniform during inflation, makes the approach most applicable for „in-position‟ (IP) analyses with fully inflated airbags. In contrast, an analysis may be characterized as „out-of-position‟ (OoP) if the occupant interacts with the airbag before it is fully deployed.

In a traditional automobile noise, vibration and harshness (NVH) analysis, stationary tires are defined and subjected to vertical dynamic loading. The actual operating condi-tions of a tire involve rolling however, and the vibration characteristics of rolling tires are considerably different from those of stationary tires. Abaqus offers a methodology to include the pre-loading and gyroscopic effects of rolling tires in a forced response dynamic analysis of the moving vehicle.

In the automobile industry, kinematics and compliance (K&C) testing is used to evaluate the ride and handling performance of an automobile. The traditional approach to numerical simulation of K&C testing involves the use of multi-body dynamics software, which simplifies the phys-ics by introducing rigid body assumptions. In this Technology Brief, a new methodology for K&C simulation is demonstrated using Abaqus/Standard.

Accurate simulation of an anti-lock brake system (ABS) requires detailed modeling of separate subsystems in dif-ferent physical domains. Creating refined models of the brake, wheel, and control components with a single analy-sis tool is difficult, if not impossible. The strategy of co-simulation can be adopted to meet this challenge; differ-ent simulation tools can be used simultaneously to create multi-disciplinary and multi-domain coupling. In this Technology Brief, a co-simulation approach using Abaqus and Dymola is used to achieve a realistic system-level simulation of an ABS.

The Biofidelic Rear Impact Dummy (BioRID-II) hardware model has been developed to measure automotive seat and head restraint system performance in low-speed rear end crashes. It has also been used to further the under-standing of whiplash injuries. This technology brief fo-cuses on the Abaqus BioRID-II finite element model, which has been developed in cooperation with the Ger-man Association for Research in Automobile Technology FAT. The capabilities of the model will be described, and a comparison with experimental data is shown.

Tires are the only load transfer mechanism between a vehicle’s suspension and the road. Consequently, tire vibration has a significant impact on ride quality and vehicle interior noise.

The B-pillar is an important load carrying component of any automobile body. It is a primary support structure for the roof, and is typically a thin-walled, spot-welded, closed-section structure made from high strength steels. As part of the validation process, the B-pillar can be ex-perimentally loaded at quasi-static rates until failure†. The force and displacement of the impactor are measured to get valuable insight into the stiffness characteristics of the structure.

During product development, design engineers often have the freedom to modify a number of parameters. However, any design modification requires validation to ensure the satisfaction of requirements for all load cases. With Abaqus for CATIA V5 (AFC), nonlinear finite element technology is made available within the CATIA environment, allowing design engineers to efficiently incorporate accurate stress analysis into the design process. In this Technology Brief two approaches are described to illustrate the productivity gains possible with AFC.

This technology brief illustrates typical mode-based noise, vibration, and harshness (NVH) analyses of a full automobile model using the Abaqus product suite. Abaqus/AMS, the automatic multi-level substructuring eigensolver, is used to compute the eigensolution. A steady-state dynamic analysis is then performed in Abaqus/Standard. The significant performance benefit of using Abaqus/AMS and the SIM-based linear dynamics architecture will be demonstrated for uncoupled structural and coupled structural-acoustic analyses.

A methodology to study the sound radiation of engine valve covers is presented. The analysis process uses a nonlinear static simulation followed by a steady state dy-namics simulation to determine the sound pressure field due to the vibration of the engine cover. The effects of assembly loads are included. The methodology is dem-onstrated with two representative engine valve covers using acoustic finite and/or infinite element methods. Good correlation between the analysis results and avail-able experimental data is achieved.