Non-smooth dynamics of coil contact in valve springs

摘要: This contribution describes the dynamic simulation of contact coils a valve spring within multi-body system application. The is described by multi-mass model. Contacting influence dynamical properties significantly. possible interaction between adjacent modeled means non-smooth mechanics. Signorini conditions on displacement level are imposed candidates. set inequality constraints transformed into equations introducing nonlinear complementarity function, which contains semi-smooth maximum function. motion together with integrated in time Backward Differentiation Formula (BDF) scheme. In each step, resulting algebraic equation solved Newton method. approach evaluated two examples. first model represents cylindrical helical spring. performance algorithm compared to an approach, where coil using spring-damper elements nodes. proposed not only running much faster, but also avoids need artificial parameters calibrate elements. second example deals full single valvetrain system, demonstrating that train dynamics widely affected vibrational characteristics springs.