Dynamic Analysis and Design of Motorcycle Mounting System Subjected to Road Loads

Fadi Alkhatib

doi:10.11648/j.ijmea.20160405.11

Abstract

This paper presents a comprehensive model of a motorcycle mounting system. The model presented herein consists of two main assemblies. The powertrain assembly and the swing-arm assembly are modeled as a six degree of freedom rigid bodies. The two assemblies are connected to each other using a shaft that is usually referred to as the coupler. The connection points on both assemblies are known. Unlike automobiles, motorcycle performance and handling is highly affected by the external disturbance. In addition to minimizing the shaking loads, the mounting system must be set up such that it also minimizes the external disturbance from the environment such as irregularities in the road profile and road bumps. This disturbance can be transmitted through the tire patch to the engine causing it to hit nearby components. The engine movement needs to be minimized due to space limitations surrounding the engine. In order to do so, these transmitted external loads must be minimized by the use of the mounting system. The load minimization process is achieved by selecting the optimum stiffness parameters, location and orientation of the mounting system that are supporting the engine. This goal is achieved by an optimization scheme that guarantees that the transmitted loads are minimized. An investigation will be done to explore the effect of different road profiles on the mount final geometrical shape.

Highlights

In the paper presented the effect of external loads on the mounting system is investigated
The force transmitted through the engine mounts due to both the shaking force at 4000 rpm and the road loads described in the profile shown in Fig. 4, are used to formulate the objective function shown in Eq (23)
The second part of the problem starts by setting the objective function described in Eq (26) to minimize the difference between the desired stiffness values obtained from the first optimization done through the dynamic analysis and the stiffness values obtained from the geometric shape of the mount

Summary

Introduction

In the paper presented the effect of external loads on the mounting system is investigated. One of the main problems that engineers encounter in vibration isolation is the problem of motion isolation This problem is seen in the case of external loads that are transmitted to the engine. The design of engine mount has been addressed by [16] He suggested treating the mount orientation and stiffness as variables. In the work presented a shear (bush) mount which is made of rubber is used This type of mounts is commonly used in passenger cars due to its low cost. A study of the dynamic analysis and parameter identification of a rubber isolator using MaxwellVoigt model is presented in [17].

Dynamic Analysis

Road Loads

Optimization Problem

Shape Optimization

Numerical Example

Conclusion