Abstract
Multibody mechanical systems that have hard stops or joint clearances, encounter changes in the system kinematic structure. Due to the joint clearances or hard stops, internal impacts within the joint geometry occur. As a result of these impacts, nonlinear contact forces of unknown nature are created, which act and disappear over a short period of time. These forces or their corresponding impulses are transmitted throughout the system. In this paper, a methodology for treatment of multibody mechanical systems with hard stops and joint clearances is discussed. The methodology is based on the development of different contact force models that include energy absorption, with which a continuous analysis of the system undergoing internal impact is performed. The concept of effective masses is used to take into account the effect of the entire system rather than the link or the joint that encounters a discontinuous motion. The methodology is more suitable than the conventional impulse / momentum formulation in its treatment of multiple impacts and it guarantees accurate solutions no matter how hard or soft the stops are. The method discussed is applied to a point follower mechanism and an aircraft landing gear latch mechanism.
