Complex built-up mechanical structures can be made of panels and beams, which are connected via different types of joints, such as spot welds, bolted joints, seals, gaskets, glued connections etc. Two important issues concerning the dynamic modeling of joints involve the computational burden of including a detailed model of the joint into the system model and the possibility of including variability and uncertainty, typical for joints, in a full-scale model of the complete structure. In the general framework of developing engineering tools for virtual prototyping and product refinement, these two issues drive the need for the development of simplified equivalent joint models, to be readily included in full-scale NVH (noise, vibration and harshness) models at a reasonable computational cost. This paper concerns the structure-borne vibration transmission of a highly non-linear type of joint: a car door weather seal. A non-linear finite element model, which accounts for the amount of pre-stress of the seal, is used to identify an equivalent linearized seal model that can be included in a full-vehicle linear NVH model. A simplified two-dimensional set-up is used to describe a car door weather seal. A non-linear finite element model is developed to investigate the role of the seal pre-stress on the door dynamic response. The seal influence on the door dynamic response is divided in three main contributions: a damping, a resonant and a stiffness contribution. The results are used to extract an equivalent linearized seal model (without considering the door) in the form of a mass-spring- dashpot system to include in a full-vehicle linear NVH model. This paper focuses on the seal stiffness contribution, which is modelled by an equivalent spring only. The seal resonant and damping contribution, together with the modelling of its viscoelastic characteristic, and the experimental validations of the presented results, are next steps of research. When a complete seal equivalent model will be established, typical uncertainty and variability levels for the joint will be introduced, and various Monte Carlo runs of a cost-efficient system model will be performed to provide the response statistics.
Dynamic modeling of car door weather seals: A first outline
Erste Grundzüge eines dynamischen Modells für Fahrzeugtürdichtungen
2004
13 Seiten, 30 Bilder, 1 Tabelle, 10 Quellen
Conference paper
English
The Development of Testing Device for Compression Deformation of Automotive Door Weather-Strip Seals
British Library Conference Proceedings | 2002
|The Development of Testing Device for Compression Deformation of Automotive Door Weather-strip Seals
SAE Technical Papers | 2002
|