# Pretreatment of LTCA finite element analysis model of spiral bevel gear

The pre-processing of spiral bevel gear finite element analysis includes the selection of elements, the setting of analysis types, the application of loads and boundary conditions. These settings determine the correctness of the analysis results and are the key technology of finite element analysis.

(1) Definition of material: set the elastic modulus of large and small wheels to 209 GPA and Poisson’s ratio to 0.3.

(2) Definition of element attribute: hexahedral one-time reduced integral element (c3d8r) is adopted.

(3) Definition of analysis type: implicit and static analysis algorithm is adopted, and the calculation step in the analysis process is 0.1.

(4) Definition of contact pair: define the tooth surfaces of large wheel and small wheel as contact pairs, and set the friction factor in tangential contact attribute to 0.15.

(5) Definition of boundary conditions: constrain all degrees of freedom of the reference point of the large wheel except the degrees of freedom rotating along the axis, and constrain all degrees of freedom of the small wheel.

(6) Definition of analysis step: in order to ensure the convergence of initial contact analysis of gear teeth, the analysis process is divided into three steps:

① At the initial position where there is tooth side clearance on the contact tooth surface, apply a small amount of rotation on the degree of freedom of the large wheel around its own axis, and the small wheel applies a fixed boundary condition, which can eliminate the tooth side clearance and make the two tooth surfaces contact. At the same time, there is no rigid body displacement in the calculation process to ensure the convergence of the initial contact iterative calculation;

② Remove the small rotation of the large wheel, add the torque on the degree of freedom around its own axis, and complete the analysis of the contact state under the initial load;

③ The rotation angle boundary condition is applied to the small wheel to make the small wheel drive the large wheel to rotate, so as to complete the simulation of the whole meshing process.

(7) Load definition: define the torque of large wheel 15 Mn · m, and the load increases linearly from zero to the maximum in the whole analysis step.

Scroll to Top