Topology Analysis of Bicycle Rim Brake Pad to Improve Braking Performance

Keong, Le-Onn (2018) Topology Analysis of Bicycle Rim Brake Pad to Improve Braking Performance. Final Year Project (Bachelor), Tunku Abdul Rahman University College.

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Abstract

Various parameters of rubber brake pad tribology will affect the braking performance of a rim brake system of a bicycle. Out of those, three main parameters are contact length of brake pad, surface topology of friction surface, and the thickness of rim brake pad. The findings will answer the problem statement of the inefficiency braking performance of a conventional rim brakes that usually has low friction performance. The goals of this study are to improve the braking performance of rim brakes to have better friction performance while retaining its simplicity of manufacturing and to investigate the effect on friction performance through the modifications of external dimensions and surface topology of rim brakes. Moreover, through this study, it can reveal which topology modifications of the rubber brake pad will have the most significance effect towards friction performance. Both experimental measurement and numerical analysis method will be used throughout this study. Experimental measurement is used to obtain surface properties between two contacts in terms of coefficient of friction, while numerical analysis will be used to perform the parametric study to obtained friction performance of the rubber brake pad. The parametric study will be simulated using Transient Structural (Mechanical APDL) with ANSYS. Mechanical APDL is suitable for simulating deformation problems and response of material to short period of severe loading. Simulation is effective in a way as the cycle time for final product design and its validation can be reduced significantly. Additionally, to ensure a thorough parametric study, Taguchi design method is used. As for the baseline model, a standard low cost rubber brake pad with three grooves is selected and this will be the reference product for the rest of the analysis later. Parametric study results show smaller groove and smaller width contribute to higher friction performance. Stress concentration will occur at the edge of groove; hence, by reducing number of groove, it allows higher braking force to be generated. Location of groove concentration appears to have insignificance effect to the friction performance. Through the topology modifications, it improves the braking performance by 3%. As for external dimension, thick rubber brake pad will not demonstrate any improvement and longer contact length will demonstrate higher friction force. However, it has to be bounded by the practicality of the dimension. Upon modifications at the external dimension, it has an improvement of 64% from the baseline model. Therefore, improvements are made through parametric study.