Nonlinear constitutive force model selection, update and uncertainty quantification for periodically sequential impact applications

Abstract

Contact–impact events frequently occur between solid contact interfaces in complex dynamic mechanical systems and engineering applications. Impact force models are used to determine the responses of contacting solids. The selection of the impact force model strongly affects the predictions of the dynamic behavior of the contacting bodies, mainly in sequential repeated impacts. In this work, the strong nonlinear dynamic behavior of a cantilever steel beam, repeatedly impacting a steel rigid stop, is investigated applying experimental and numerical methodologies. The applicability of a nonlinear constitutive force model selection and model-updating framework at engineering problems where contact–impact phenomena happen in a sequential periodic manner is presented. At first, the dynamic behavior of the examined problem due to variation in impact parameters, excitation frequency and applied force model is examined. The general viscoelastic impact force law based on the Hertz contact theory, augmented with a damping term is integrated in the FE model. Experimental trials of the impacting cantilever beam under base excitation were carried out, and a model selection process between nine different expressions of the viscous term at a constant impact parameter is performed. Inadequacy of the updated selected model dictated a new model selection approach including the constant impact parameter. A new model selection and updating process is finally presented in order to tune and study in detail the effect of impact parameters and clearance gap between the contacting bodies in a specific sinusoidal excitation frequency of the impacting cantilever beam, validating the experimental results.