Investigation Into Design Methodology Of Mountain Bikes Considered Biomechanics

This dissertation presents the theory and methodology for the design of a mountain bike with full suspensions, including dynamic modeling, simulation, experiment testing, performance evaluation and parameter design. The following contributions have been made.By taking the mountain bike with full suspensions as examples, the dynamic model of the rider-mountain bike coupled system is constructed using the theory of multi-body system dynamics and biomechanics. By means of ADAMS dynamic analysis software, the simulations of kinematics and dynamics are implemented.An experiment methodology is developed to reflect the real mountain biking status. By separating the experimental instruments and the testing bike, the vibrating data have been acquired without error produced by rough road surface. With the comparison of the results of simulation and testing, they are coincident with each other. It turns out to be that the modeling theory and methodology is correct and validity.The performance evaluation indices of mountain bikes are investigated from fatigue, comfort and security. It concludes that the quadratic sum of rider lower limb muscle tensions is taken as the evaluation index of fatigue, the weighted root mean square acceleration of saddle and middle axle is taken as the objective evaluation index of vibration comfort, the weighted mean quantifiable value of rider uncomfort sense is taken as the subjective evaluation index of vibration comfort, and the fatigue stress is taken as the evaluation index of frame stress.Based on the performance evaluation of biomechanics and the vibration comfort, the scale parameters design of the frame and the rear suspension is investigated. The prediction formulas of human muscle fatigue and vibration comfort have been acquired. It shows that the parameters of rider are the important factor in the design of mountain bikes. The outcome of this dissertation has provided a complete theoretical package for the design of the mountain bikes, which is being used as a reference for the development of the common bikes, the superior bikes and the electric bikes.