Study On Design Method Of Mail Bicycle Based On Riding Safety And Comfort

In this paper, according to the Post Office's need to improve the mail bicycle, design method of mail bicycle based on riding safety and comfort is discussed.The main research achievements are shown as follows:1. Based on the consideration of riding safety, fatigue strength of Chinese and another country's mail bicycles under different cycling and loading conditions are checked using finite element method before the following contrast. The result shows that although the two products both meet the fatigue strength requirement, the another country's one is apparently superior in distribution of stress, structural rationality, etc.2. Considering the recent bicycle structure and working environment of mail carriers under the preconditions of riding safety, some reasonable plans of bicycle structure and spare parts are proposed.3. According to the Post Office's real need, the Chinese bicycle's front fork is checked in finite element method in order to find out the reason of its break. At the mean time, two new improvement plans are brought forward to reduce maximum stress as well as quality. The best plan which can not only improve the stress distribution of front fork under heavy loading conditions, but also make the quality range under control is searched in different ways.4. In order to study the riding comfort of mail bicycle, the cycling experiment with surface electromyography analyzing method is made which involves different cyclers. Time and frequency domain analysis are made to testify the validity of simulation whose purpose is to measure the muscle forces as well as to improve bicycle designing theory. At the same time, the conclusion is drawn that another country's bicycle is superior to the Chinese one in the consideration of muscle fatigue through the slope of linear fitting equation of MF which is seen as an evaluation index for muscle fatigue. This evaluation index is used to make a comparison between the recent and another country's mail bicycles on riding comfort and it shows that the former one is superior to the latter one.The achievement of this paper offers a great value to the innovation of bicycle designing method in theoretical and practical ways.