Multi-support shafting finite element method with bearing stiffness coupling nonlinearity considered

Abstract

The invention relates to a multi-support shafting finite element method with bearing stiffness coupling nonlinearity considered. The method comprises the steps of (1) establishing a local coordinate system of each bearing and obtaining a six-freedom-degree bearing stiffness matrix of each bearing under the corresponding local coordinate systems through calculating by means of the difference method with a corresponding bearing load calculation formula; (2) dividing a shaft into different shaft sections according to the difference of diameters, establishing nodes at the positions of bearing section starting positions, the bearing installation position and load action positions, then establishing finite element models of the shaft between the nodes, and obtaining a stiffness matrix of the whole shaft; (3) establishing a global coordinate system of a shafting, establishing another node at the bearing installation position to be used for simulating a fixed end, integrating the bearing stiffness matrix onto the installation node and the corresponding fixed end node on the shaft to obtain the overall stiffness matrix of the shafting, and establishing the stiffness equation of the shafting; (4) restraining the freedom degrees in six directions of the fixed end node, restraining the freedom degree, of rotating around the axis, of the node at the position of origin of the global coordinate system of the shafting, reducing the stiffness equation of the shafting according to restraining conditions, and solving the reduced stiffness equation of the shafting with the Newton-Raphson method in an iterative mode to obtain the displacement and load of each node.

Description

technical field [0001] The invention relates to a finite element modeling and analysis method, in particular to a multi-support shafting finite element method for multi-support shafting in the field of structural analysis that comprehensively considers the stiffness coupling and nonlinearity of bearings in all directions. Background technique [0002] In a multi-support shaft system, each drive shaft is supported by multiple bearings, and the load and displacement of the bearings are coupled in different directions, and the change of load and displacement is nonlinear, that is, the bearing stiffness has the characteristics of coupling and nonlinearity. Therefore, the analysis of the whole system is a complex nonlinear problem. The difficulty in the calculation and analysis of multi-support shafting system is how to deal with the calculation of bearings. It should not only take into account the coupling and nonlinearity of its stiffness, but also be able to combine with the c...

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Problems solved by technology

This method can more accurately simulate the influence of the internal structure of the bearing on the deformation, but the modeling process is complex, and because it involves nonlinear contact calculations, the calculation amount is large and the efficiency is low, so it is rarely used to analyze the entire shaft system. For single bearing studies only

[0004] In addition to the above methods, the existing general-purpose finite element software cannot handle the coupling and nonlinearity of bearing stiffness at the same time, so it is impossible to realize the analysis and calculation of multi-support shafting systems considering the coupling and nonlinearity of bearing stiffness

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