Probabilistic Modeling of Mechanical Joints

摘要

Real physical systems subjected to dynamic environments all display nonlinear behavior, yet, for practical reasons, they arernmost frequently modeled in a linear framework. Experience shows that much of the nonlinearity of system behavior arisesrnfrom the dynamic action of mechanical joints in systems. Further, experimental evidence suggests that real physical systemsrndrawn from ensembles of nominally identical systems are stochastic, yet, most modeling is deterministic. When therndeterministic, linear framework is used, the stiffness of joints is modeled as linear, and the damping is modeled as linear andrnviscous. To model mechanical joints otherwise requires a nonlinear framework and mathematical finite element model thatrnaccommodates transient time domain analysis. This study investigates energy dissipation in a particular type of mechanicalrnjoint – the lap joint. It does so using a mathematical model originally implemented in a deterministic framework. Therninvestigation develops a methodology for incorporating the energy dissipation model into a probabilistic framework, and usesrnexperimentally generated results to develop a specific probabilistic model. A numerical example is presented.