| In order to-solve the problem of friction coefficient dispersion of Zinc-coated High-strength bolts for subcompact, this master’s thesis deeply researched the friction attribute by combined the overseas and domestic researches, and integrated analysis of theory and simulation. The effect of friction coefficient on the nut factor, fastening yield axial force and fatigue property were analyzed, which aimed at finding out the regularities of the influence of friction coefficient on tightening attribute, and the best control range of friction coefficient in theory. Then this thesis analyzed the effect of friction coefficient on tightening attribute based on experimental research, which aimed at finding out the control method of friction coefficient. Finally, the stability of friction coefficient and the tightening attribute of bolt fastening were improved, which based on the results of theoretical analysis and experimental research. The main research achievements are as follows:1. The force model of bolts was analyzed integrality, and the mathematical regularities of the influence of friction coefficient on the nut factor was found out.2. The influence of friction coefficient on fastening yield axial force was analyzed, which found out that the traditional formula of bolts design didn’t concerned the influence of friction coefficient, which would result in material wasted or safety accident. To solve this problem, this thesis put forward a corrected formula.3. The influence of friction coefficient on residual stress was analyzed through the collaborative simulation of ABAQUS and FE-SAFE, and the mathematical regularities of the influence of friction coefficient on the fatigue property was found out.4. The effect of friction coefficient on tightening attribute was analyzed based on experimental research, which confirmed the key factors that were likely to influence zinc-coated bolts friction coefficient. Meanwhile, experimental research found that D chromate treatment Zinc-coated High-strength bolts were superior to C chromate treatment on all aspects of performance.5. The key factors which effected zinc-coated bolts friction coefficient were controlled, that successfully solved the problem of friction coefficient of dispersion. Meanwhile, by using the theoretical analysis results that about the influence of friction coefficient on tightening attribute, improved the performance of bolt fastening. |
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