Study Of Hopf Bifurcation Effect On Automotive Brake System Induced By Dry Friction

The groan and judder of the automotive brake system not only effect automotiveoperational performance and passenger comfort but also pollute environment. Therefore,scholars focus on them. At present, the research of vehicle groan and judder is focusedon Hopf bifurcation induced by dry friction of single-cylinder brake system and theconsequent stable limit cycle. As for the relationships of unstable limit cycle anddouble-cylinder brake system, the research is less. The main contents of this thesis areas follows:(1)A single-dof model of single-cylinder brake system was established and a dryfriction model of hysteretic effects was used. Hopf bifurcation effect on single brakesystem induced by dry friction was researched by the numerical simulation method. Theresult shows that there are multiple limit cycles which include a stable limit cycle andstable limit cycle. And brake pressure and friction coefficient effect the multiple limitcycles obviously.(2)A2-dof model of double-cylinder brake system was established and a dry frictionmodel of hysteretic effects was used. Hopf bifurcation effect on single brake systeminduced by dry friction was researched by the numerical simulation method. The resultshows that there are multiple limit cycles which include2stable limit cycles and stablelimit cycle. Brake pressure and friction coefficient effect the multiple limit cyclesobviously. And the amplitude of double-cylinder and double-pad brake is much smallerthan that of double-cylinder and single-pad brake.(3)A double-cylinder brake system judder model was established based on sprag-slip.The double-cylinder brake system judder mechanism induced by qualitative analysismethod. The influence of brake pressure, brake angle and mass ratio on judderamplitude was researched by the numerical simulation method.