Simulative Investigation of Wheel Brakes in Terms of the Anchor Load and Pad Movement

In the research project between the Institute of Automotive Engineering (FZD) of the Technische Universität Darmstadt (TUD) and Continental Teves AG & Co. oHG a new modeling concept has been developed. With the aim to enhance the current development process, the brake caliper is modeled based on coupled rigid bodies integrated into a nonlinear system model. Using an explicit interface definition, the number of degrees of freedom is minimized and the calculation of caliper performance is possible over a wide range of parameters. Compared to models based on the Finite Element Method (FEM), fully parameterized geometry from CAD is not necessary, thus the caliper can be optimized for a variation of its geometrical and physical parameters. With this modeling approach, typical performance criteria such as caliper fluid displacement, hysteresis, uneven pad wear and residual torque can be calculated in a virtual bench test. Additionally, the pull-push-characteristic and the tendency towards radial pad movement can be assessed. The results are generated before assigning the design parameters in CAD and are suitable to achieve frontloading in the development process. In this paper, the basic approach and the experimental validation regarding the force distribution between inner and outer pad and also the radial pad movement are described. For the validation a high-performance flywheel-dynamometer is used. The tangential load and the pull-push-characteristic are measured with strain gauges on the anchor arms. The inductive linear displacement sensors gauge the radial pad movement. The results show the development process of radial pad movement over time and the sensitivity of different parameter variations.