Dynamics of the Spatial Motion of the Long Boom Manipulator Based on Nonlinear Beam Element

The boom systems of mobile cranes and aerial platform vehicles are usually designed as long and slender boom structures thus can be regarded as long boom manipulators. The dynamics of the long boom manipulator is a rigid-flexible coupled problem due to the elasticity of such a slender boom structure is not negligible. One of the difficulties for this problem is to deal with the geometric nonlinearity comes from the combination of the large rigid motion with flexible deformation. The purpose of this paper is to develop a dynamic model for the spatial motion of the folding boom system, an example of the long boom manipulator. A kind of nonlinear beam element is applied to formulate the motion and the deformation of the flexible bodies in the global coordinate. A numerical smooth method is also introduced to reduce the cost time of the solution by filtering high-frequency parts in the formulation of the element strain. The dynamic equations are solved by the ODE solvers in MATLAB. And the performance of the proposed model is verified with NODYA, a finite element program well developed by our chair.