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Stiffness of a Nonlinear Adiabatic Polytropic Air Spring Model: Quantitative and Conductive Investigation

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The conservation of mass and energy formulas along with the Newton’s second law of motion are used to derive a simple nonlinear adiabatic air spring model. The purpose of this paper is to evaluate air spring stiffness and identify the characteristic behavior of this model. The model consists of six coupled nonlinear differential equations. The assessment of this model is based on solving these governing equations numerically using the Runge Kutta routine Matlab based platform. It has been found out that the air spring stiffness increases exponentially with the increase in the air spring piston diameter. Due to its sensitivity and its nonlinearity, the model shows signs of chaos, which have been observed in the vertical motion or in the control volume, pressure for the chosen range of parameters.
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Air spring; Newton’s Second Law; Conservation of Energy; Isentropic Relations; Runge Kutta Method; Compressible Bernoulli’s Equation; Orifice Flow; Chaos; Poincaré Map

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