ABAQUS 汽车 Automobil And Engine Acoustics Applications And Analysis With Abaqus.ppt

Automobile Acoustics Applications and Analysis with ABAQUS July 2005 Automobile Acoustics Applications and Analysis with ABAQUS Overview Overview Introduction ABAQUS Software Acoustics Capabilities Examples Pick-up Truck Muffler Current Work Summary The Next Step QA Automobile Acoustics Applications and Analysis with ABAQUS Introduction Introduction Noise and vibration of motor vehicles is receiving unprecedented attention in recent years primarily due to: Legislation governing the ambient level of traffic noise Increased contribution of sound quality to overall customer satisfaction Cost associated with warranties (e.g. brake squeal) Automotive noise may typically be divided into: Structure-borne noise and vibration Airborne noise In this webinar, we will focus mainly on airborne noise. A follow-up webinar on Full Vehicle Noise, Vibration, and Harshness (NVH) is planned for early 2005. Introduction Sources of vehicle noise are diverse: Engine Tire-road interface Intake, exhaust Gearbox, transmission, fans Flow noise Mechanisms to control or reduce noise are also diverse: Modifying the geometry and materials Modifying the contact conditions Using absorptive materials and treatments to dissipate acoustic energy Using acoustic techniques to redefine acoustic transmission paths Due to the lack of complete understanding of engineering acoustics, this field still remains somewhat of art requiring the interplay of experiments, numerical modeling techniques, and a significant contribution from the analyst ! Introduction Some applications are efficiently handled through the FE method, while some others may require alternate approaches such as the Boundary Element Method (BEM), Energy Flow Methods (EFM), Statistical Energy Analysis (SEA), Ray Tracing, etc. FEA aims to answer questions such as: How does my particular piece of equipment work? What is the interaction between the structure and the acoustics? How can we satisfy the structural requirements while simu