Based on exact Green strain of spatial curved beam,the nonlinear strain-displacement relation for plane curved beam with varying curvature is derived.Instead of using the previous straight beam elements,curved beam elements are used to approximate the curved beam with varying curvature.Based on virtual work principle,rigid-flexible coupling dynamic equations are obtained.Physical experiments were carried out to capture the large overall motion and the strain of curved beam to verify the present rigid-flexible coupling formulation for curved beam based on curved beam element.Numerical results obtained from simulations were compared with those results from the physical experiments.In order to illustrate the effectiveness of the curved beam element methodology,the simulation results of present curved beam elements are compared with those obtained by previous straight beam elements.The dynamic behavior of a slider-crank mechanism with an initially curved elastic connecting rod is investigated.The advantage of employing generalized-α method is pointed out and the special nonlinear dynamic characteristics of the curved beam are concluded.
Instead of using the previous straight beam element to approximate the curved beam,in this paper,a curvilinear coordinate is employed to describe the deformations,and a new curved beam element is proposed to model the curved beam.Based on exact nonlinear strain-displacement relation,virtual work principle is used to derive dynamic equations for a rotating curved beam,with the effects of axial extensibility,shear deformation and rotary inertia taken into account.The constant matrices are solved numerically utilizing the Gauss quadrature integration method.Newmark and Newton-Raphson iteration methods are adopted to solve the differential equations of the rigid-flexible coupling system.The present results are compared with those obtained by commercial programs to validate the present finite method.In order to further illustrate the convergence and efficiency characteristics of the present modeling and computation formulation,comparison of the results of the present formulation with those of the ADAMS software are made.Furthermore,the present results obtained from linear formulation are compared with those from nonlinear formulation,and the special dynamic characteristics of the curved beam are concluded by comparison with those of the straight beam.
