System-Level Simulation of Air Disc Brake under Dynamic Braking Conditions for Design Optimization

Air disc brakes are commonly used in trucks due to their superior performance compared to conventional drum brakes. To validate the brake assembly, extensive physical tests are conducted for the required brake torque condition. The aim of the study is to correlate the physical test deformation and failure modes using finite element analysis (FEA) and to optimize the design variables. Initially, there was a correlation gap between the test and FEA as the braking event was simulated with estimated static loads at the interfaces. Though the geometry is symmetric, during brake application, there are unsymmetric loads acting on the assembly along the direction of the rotation of the rotor due to dynamic deformation as the torque is generated at the friction pad interface. To simulate this unsymmetric behavior, the dynamic implicit analysis procedure with a moderate dissipation approach in Abaqus/Standard is used. To correlate the clamping force required to generate the braking torque achieved in the physical test while rotating the disc, dry and sliding friction parameters and the modeling of other mechanisms are iterated. By using this approach, the tangential loads at the friction interface, load transfer through other contact interfaces, and corresponding changes in stress levels are well captured. With this improved method, the deformation modes and failure locations are well correlated with the physical tests with an optimized simulation time. As contact interactions are well captured in assembly-level simulations, further part-level design iterations can be carried out by mapping interaction loads from other parts. Due to the improved accuracy of the FEA methodology, topology optimization is also carried out to reduce mass by a considerable amount. This FEA methodology adds value to the organization as it helps in validating and optimizing the brake assembly at the initial concept phase itself to achieve the required fatigue performance at the design-rated torque.