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A method for predicting the propensity of a drum brake system to produce noise is presented. The method utilizes finite element models of the individual components of the drum brake system, which have been assembled into the system model of the brake assembly. An important step in this process is the tuning of the dynamic characteristics of the FEA model to ensure validation with experimental tests. Friction is the key element, which defines the behavior of the drum brake system. The system FEA model is assembled by coupling the lining and drum at the contact interface to simulate the friction interaction. This process produces an asymmetric stiffness matrix. A complex eigenvalue analysis identifies the system dynamic characteristics such as the frequency and damping for each vibration mode. The damping values reveal which modes are unstable and therefore likely to produce noise.

Only products with high quality, low cost, and short concept-to-customer time will continue to have a high market share. For this reason, auto parts suppliers must strive to gain superior engineering capability. One key step in this pursuit is to implement widespread CAE (Computer-Aided-Engineering) in PDP (product development process) [1]. FEA (Finite Element Analysis), in particular, has been identified as a subject that deserves concentrated effort. Specifically, FEA needs to be used broadly and effectively in every phase of PDP ranging from concept evaluation and prototyping, to pre-production design and troubleshooting. However, resource requirement and process quality assurance are major issues in this undertaking [2, 3]. As a counter-measurement, developing product specific FEA guidelines has been identified as a priority strategic initiative. The focus of our presentation is on how to develop standard FEA procedures to guide FEA jobs.

This paper presents a methodology for predicting drum brake performance using FEA (finite element analysis) models considering both the mechanical-structural compliance and thermal effects. The methodology for brake torque prediction with FEA models considering the structural flexibility of the brake components alone has been established [1]. The frictional heat generated during braking causes thermoelastic distortion that modifies the contact pressure distribution at the drum-lining interface. In order to capture this thermal effect, a transient thermal analysis is conducted to predict the transient temperature distribution on the brake components. In the thermal analysis, the heat generated at the drum and lining interface is based on the pressure distribution from the compliant mechanical model. Also, the mechanical properties of the brake components as well as the lining friction are dependent on the temperature distribution.

Effective linear and nonlinear drum brake system FEA (finite element analysis) models have been developed. Such models can help engineers understand many drum brake related issues, such as lining wear and mechanical and thermal instability. The pressure distribution at the drum and lining interface is an important piece of information in drum brake design. Besides the accurate prediction of the shoe factor, the models can be used to guide designs for improving brake efficiency, reducing component weight and enhancing durability. Progress is also being made in developing hybrid models that integrate FEA models with other analysis techniques. This approach offers engineers easy-to-use design tools. The integrated design and analysis approach will help product design and development by reducing cycle time, cost and improving product quality.