【摘要】 本文在结构强度有限元分析中,应用计算机半自动设计技术(CAD)建立了车架与前叉组合结构空间刚架力学模型,其中考虑了接触应力的影响。通过电测对有限元分析的可靠性进行了检验,还考虑了可能出现的三种工况,由此,为QE-01型铝合金自行车车架的强度设计提供了理论依据。更多还原

【Abstract】 Objective.CAD (computer-aided design) technique was introduced into the finite element analysis of frame strength for a bicycle made of aluminium alloy.The mechanical model to be developed should tally with actual situation under different conditions so as to provide theoretical basis for bicycle body design.The whole body of a bicycle is a composite rigid structure which consists of a bicycle frame connected with a front fork through two ball bearings within the front tube of bicycle frame.A space rigid frame model,taking into account the effect of contact stress,has been developed for the composite structure using CAD technique.Numerical solution was obtained through simplifying the continuum to a discrete model composed of finite elements and applying matrix analysis.Three typical loading cases were specifically considered and calculated for matching the measurement of stress distribution,i.e.,riding in uni-fom motion,sudden overload due to quickly braking and impulsive overload in a short time as get-on and get-off.Reliability of calculated results has been checked against those measured under conditions that both loadings are just as well and all the nodes in FEM model are coincident with measuring points.Satisfactory conformity was obtained.Fig.1 Composite structure of a bicycle frameFig.2 Primary mechanical modelFig.3 Composite frame modelFig.4 Discrete model of space rigid frameFig.5 Three typical loading cases in ridingFig.6 Stress distribution as riding in uniform motionOblique,stress in upper section;Dotted,stress in lower section.Fig.7 Stress distribution as quickly braking Fig.8 Stress distribution as get-on and get-off Fig.9 Loading test Tab.1 CAD specificationTab.2 Stress difference of symmetric nodes in front forkTab.3 Restraint model specification of supports更多还原