Dynamic And Static Analysis For A Bicycle Model

Performing Finite Element Analysis(FEA)on bicycle frames has become a common activity for bicycle designers and engineers in the hope of improving the performance of frames.This is typically achieved by balancing priorities for key requirements,including minimising the mass of the frame(possibly using competition rules to constrain this),maximising lateral stiffness in the load transfer from the hands and feet to the drive,maximising the strength capabilities of the frame to allow for a higher load capacity or better load distribution,and adjusting the vertical compliance of the frame to tune the softness of the ride.In chapter 2 FEA has been used to analyse composite,aluminium and steel bicycle frames with the aim of understanding physical behaviour and improving performance relating,however a comprehensive study on the influence of key geometric parameters on the stiffness of frames has not been conducted.Specifically,chapter 3 addresses to development of a fatigue finite element analysis(FEA),fatigue testing of physical samples in a test fixture,a microstructural fatigue crack growth model to validate the FEA predictions,and ultimately a design iteration leading to an optimal solution.An FEA model is created utilizing the geometrical characteristics of the fork.To validate the model,a testing rig is used to evaluate the forks under dynamic loading.The analytical model and experimental setup are based on the ASTM F2273-03 standard for bending fatigue testing.After validation,the FEA model is iteratively used to produce an improved fork design.The proposed methodology can also be used for materials-process design and optimization for performance in bicycle forks or other structural parts and applications.In chapter 4,we present the linearized equations of motion for a bicycle as a benchmark.The results are obtained by pencil-and-paper.The bicycle model we consider here consists of four rigid bodies.The rider is rigidly attached to the rear frame with hands free from the handlebar.We assume that the results are correct and can be used as a bicycle dynamic benchmark.