Abstract:The effects of speed and pressure on the friction coefficient of a car clutch plate were studied by experiments,by excluding the impact of temperature and amount of wear on the experimental results through experimental design,the friction coefficients at different speeds and pressures were got.The results show that the friction coefficients are decreased with the increasing of slipping speed and positive pressure.Through variance analysis of the experimental data,it is proved that the experimental results are reliable,and the influence of speed and pressure on friction coefficient is relatively independent,they have no significant interaction.The approximate expression of friction coefficient of the friction plate,as well as the fitting surface of friction coefficient was got by regression analysis.By comparing fitting surface and experimental results and the analysis results by Matlab,it is found the relationship between friction coefficient and speed and pressure can be approximated by a binary quadratic equation.