Multi-Body Simulation in Bike Design
In order to improve the design and driving dynamics of bicycles, IGMR is researching various possible applications of the latest simulation methods in the field of bicycle development.
In comparable industries, the use of multi-body simulation (MBS) has long been state of the art, enabling a significant gain in knowledge in various aspects of development. However, in the design of bicycles, the potential of MBS has so far remained largely unused. To make use of the advantages of multibody simulations, the IGMR is researching various possible applications that can improve the development process of bicycles.
Motivation
The design and dimensioning of bicycles has always been a demanding task in the development process. A central role is played here by the acting operating loads to which the system components are subjected during use. However, determining the loads that occur during operation is a major challenge, since not all components are accessible for the application of measurement technology and the use of classical finite element methods is often unsuitable for mapping the dynamic behavior in demanding riding situations. With the prototype tests established in bicycle design, a minimum level of safety can be achieved, but the determination of detailed stress conditions or the development of load assumptions of all components in the system is hardly possible. The result is a poor understanding of the acting loads. This leads to a difficult development of test standards and a time-consuming and cost-intensive development process, which is often not based on realistic and meaningful load assumptions. This is specially true for new complex bicycle designs.
Goal
The goal of this research area is to enable the use of multibody simulation and to exploit the resulting advantages. A broad spectrum of possible applications is further developed, ranging from statements on driving characteristics as a function of the design to the determination of operating loads. An important research topic for the determination of operating loads is the investigation of novel simulation approaches. The aim is to simulate the stresses on the structure on the basis of real driving scenarios.
Approach
The exploration of different possible applications of MBS in bicycle development, is reflected in different applications of various simulation approaches. Probably the most applicable application in the short term is the classical, fully analytical simulation of test standards, which could significantly speed up the development process. Simulations that include the human factor are also being researched. With the help of a human model, represented by complex control loops in the multi-body simulation, statements can be made about driving dynamics. Here, configurations of eBikes can be determined that display a driving behavior as close as possible to conventional bicycles. This would facilitate the transfer of physically disabled persons to an electrified bicycle. Alternative simulation approaches are being further developed for the determination of operating loads, with the aim of simulating real driving scenarios as precisely as possible. Here, the suitability of various semi-analytical approaches is being researched, which stimulate the frame structure on the basis of measured data. In this way, detailed frame loads could be simulated for the first time based on field tests.