Haval Kamal Asker
2012 unpublished
One of the main goals during load calculations and vibration analysis for gears is the determination of deformation and stress state in teeth contact zones. This paper describes development of the finite element model for simultaneously monitoring the deformation and stress state of teeth flanks and teeth fillets for spur gears during the contact load period. The paper also describes the Finite Element Method simulation of contact conditions for spur gears teeth with complete 3 dimension
more » ... model. A suitable analysis is performed in order to select a meshed gears model which is sufficiently economic and in same time sufficiently geometrically accurate. The special algorithm for the tooth profile drawing is developed and built in currently available software (Ansys 10) for Finite Element Analysis to assure drawing of real flanks contact geometry. The optimal mesh size level is chosen, too. The described finite element models are made for the spur gear teeth during the dynamic loading state. The obtained numerical results are suitable for tracking deformation and stress hesitation with time and investigating the effect of damping coefficient on the obtained results. INTRODUCTION The contact between parts is a common phenomenon which in some cases can be treated with rigorous mathematical theory. Formulae for special cases can be found in machine design books and papers, e.g. two sphere, two parallel cylinders, cylinders on a flat plane, gear teeth, roller bearings, etc. however, these theories only describe the stress in contact region and take into consideration many assumptions and simplifications. Engineering problems often include requirements for determination of stresses far from the contact zone, so the contact behavior must be simulated properly to fine the important stresses in the system. The calculation of a gear load capacity is one of these cases. A proper computation of forces and deformation of stress throughout the model, i.e., in teeth roots. Experimental determination of stress state in spur gear teeth with real contact conditions is associated with many limitations. The F.E.M is the most appropriate numerical method that can solve this nonlinear problem, i.e., the F.E. analysis gives the possibilities for developing appropriate models in accordance with needs in modern research of nonlinear tasks. Ulaga S. et al., analyze contact problems of gears [1]. But their FEM models calculate only contact zone stresses. Dimitrijevic, D. et al., use FEA for the 2 D dynamic analysis of the stress and strain state of the spur gear [2], and Pasta, A. described a 2D FEM model developed for the analysis of a spur gear with a corrected profile [3], also, Marunic, G. [4] Studied spur gears with low values of rim thickness and investigated the maximum tooth root stress. In this paper a particular real gear is analyzed. The main characteristics of the gear is z = 17 standard tooth profile, face width = 20 mm, pressure angle α, n = 20 0, rotation wheel speed = 4.15 m / min, wheel torque T =