The Combination Of Fem And Half Plane Method In The Application Of Helical Gear Finite Element Post-processing

Helical gear transmission has a widely usage in mechanical transmission,due to its advantages of stable transmission and high efficiency. The change of contact load is the main cause resulting in the failure of gear. Thus, analyzing tooth stress distribution and deformation evolution during gear meshing process has a significant importance on the helical gear design stage. To achieve sufficient precision, current popular commercial finite element analysis software have to discrete the contact region with much small dimension and thus bring lots of element to represent the sharp displacement variation close to contact region, this deal causes a really heaven computation burden. What is more, the huge number of element also defers considerably its post-processing. In order to overcome these shortcomings, this paper combined the basic theory of finite element method and elastic contact mechanics to complete the finite element calculation and post-processing of helical gear through programming. In this paper, the specific research work are as follows:1) According to the principle of spiral bevel gear surface formation and the gear basic parameters, completed helical gear model through the program, defined the grid cell based on the characteristics of helical gear tooth profile. Derived the node and unit data of helical gear through program, completed helical gear model in finite element software through APDL orders.2) According to the principle of finite element method and elastic contact mechanics, the stress and displacement calculation formula was derived, and obtained the stress and displacement result on the nodes of helical gear.3) The post-process was conducted in program and finite element software respectively. Finite element method and elastic mechanics are integrated applied in post-process of helical gear in the program, the concrete process is: centering on the contact line, designate an inclined semi-cylinder area, within the region, adopt the calculation results of elastic mechanics; outside the region, adopt the calculation results of the finite element method, combine the both results and visually displayed through the program. Make use of the general post-processor to display the calculation results in finite element software.4) In program and finite element software,the finite element analysis computation time were compared. In the process of post-processing, take the displacement graph and stress nephogram as examples, compared the difference about results of two kinds of post-processing methods.5) Show the results displayed in various ways of combining the finite element method and half plane method.This paper successfully combined finite element method and elastic mechanics theory in finite element analysis of helical gear, and developed a set of finite element analysis program of helical gear in MATLAB, compared with the finite element software, the calculating speed is faster, the display precision is higher, and it has better adaptability and flexibility in the post-process.