Finite Element Simulation of Energy Loss in Friction Brakes
Examensarbete för masterexamen
Automotive engineering (MPAUT), MSc
The focus of the automotive industry is shifting towards the development of electric vehicles due to the advances in battery technology and increasing environmental concerns. One of the main challenges with electric vehicles is "range anxiety" or the worry over the distance a vehicle can travel before needing to be recharged. Energy efficiency is therefore an important factor in improving the range of electric vehicles, and understanding the mechanisms that contribute to energy loss in a vehicle is crucial. Brake drag is one such mechanism, and it is estimated to account for around 3% of energy loss in a vehicle. Improving the energy efficiency of friction brakes can help address range anxiety and improve the overall performance of electric vehicles. Virtual validation of brake drag torque was carried out using the finite element tool Abaqus to validate the brake drag mechanism of a friction brake assembly on both a qualitative and quantitative level. The approach involved creating an augmented model of the friction brake assembly and defining boundary conditions and contacts to simulate the behavior of the system under static conditions. A parametric study was conducted to investigate the influence of the longitudinal stiffness of the caliper housing and friction pad lining on brake drag torque. The study also included an investigation of the impact of modifying the stiffness of the omega spring. The results of the simulations were used to mimic the relationship between brake pressure and brake drag (including the "drag knee-point") and to validate the model. The virtual environment model developed in this work can be used to quickly and accurately model and simulate different design prototypes, leading to reduced development time and optimized brake performance. The caliper housing stiffness and friction pad stiffness were found to be major factors that influence the brake drag, and the deflection behavior of the omega spring was also an important factor. It was observed that the virtual environment model can help achieve drag torque reduction with optimal brake performance. The results of the simulations were compared with existing research data and were found to be accurate. Overall, this work demonstrates the usefulness of virtual modeling and simulation in the design and optimization of friction brake assemblies.
FEM , friction brake assembly , contact analysis , Abaqus , battery , energy loss , brake drag , range anxiety , drag knee-point , electric vehicles