Application of Finite Element Analysis for Determination of Load Share, Real Contact Ratio, Precision of Motion, and Stress Analysis

1996 ◽  
Vol 118 (4) ◽  
pp. 561-567 ◽  
Author(s):  
F. L. Litvin ◽  
J.-S. Chen ◽  
J. Lu ◽  
R. F. Handschuh

A loaded gear drive with point contact between tooth surfaces is considered. The principal curvatures and directions at a current point of tangency, the contact paths on tooth surfaces, and the transmission errors caused by misalignment we consider as known. In this paper the following topics are covered: (1) Determination of the contact force and its distribution over the contact ellipse; (2) Determination of the tooth deflection, the load share, and the real contact ratio; and (3) Stress analysis by application of the finite element method. The discussed approach is illustrated with a numerical example.

Author(s):  
Manfred Schaaf

The European Standard EN 1591-1 is used for the calculation of bolted flanged joints, stress analysis as well as for tightness proofs. In this calculation procedure gasket characteristics according to EN 13555 are used to describe the mechanical and the tightening behavior of gasket materials. With further developments in the calculation algorithm and the use of the realistic gasket behavior in the calculation more detailed results can be obtained, which are comparable to results obtained from Finite Element Analysis. The flange rotation and the resulting uneven gasket stress distribution in the radial direction during the assembly of the flanged joint is the fundamental principle in this development. The effective compressed gasket width has influence on the required gasket forces for the tightness proof as well as on the mechanical behavior of the flanged joint, and thus also on the stress analysis. In this paper, the determination of the effective gasket width using a newly developed approach [1] is optimized and the verification of this approach with Finite Element Analysis for several different gasket materials and flange geometries is shown.


1995 ◽  
Vol 117 (B) ◽  
pp. 128-134 ◽  
Author(s):  
F. L. Litvin

The contents of the paper cover: a brief history of some concepts of the theory of gearing, and new developments in this area, (i) theory of enveloping curves and surfaces, (ii) simulation of meshing and contact of gear tooth surfaces, (iii) basic kinematic relations as the key to the determination of direct relations between the curvatures of contacting surfaces, and avoidance of singularities, (iv) transfer from line contact of tooth surfaces to point contact, and (v) design and manufacturing of gears with compensated transmission errors caused by misalignment.


1995 ◽  
Vol 117 (B) ◽  
pp. 128-134
Author(s):  
F. L. Litvin

The contents of the paper cover: a brief history of some concepts of the theory of gearing, and new developments in this area, (i) theory of enveloping curves and surfaces, (ii) simulation of meshing and contact of gear tooth surfaces, (iii) basic kinematic relations as the key to the determination of direct relations between the curvatures of contacting surfaces, and avoidance of singularities, (iv) transfer from line contact of tooth surfaces to point contact, and (v) design and manufacturing of gears with compensated transmission errors caused by misalignment.


2019 ◽  
Vol 13 (3) ◽  
pp. 5242-5258
Author(s):  
R. Ravivarman ◽  
K. Palaniradja ◽  
R. Prabhu Sekar

As lined, higher transmission ratio drives system will have uneven stresses in the root region of the pinion and wheel. To enrich this agility of uneven stresses in normal-contact ratio (NCR) gearing system, an enhanced system is desirable to be industrialized. To attain this objective, it is proposed to put on the idea of modifying the correction factor in such a manner that the bending strength of the gearing system is improved. In this work, the correction factor is modified in such a way that the stress in the root region is equalized between the pinion and wheel. This equalization of stresses is carried out by providing a correction factor in three circumstances: in pinion; wheel and both the pinion and the wheel. Henceforth performances of this S+, S0 and S- drives are evaluated in finite element analysis (FEA) and compared for balanced root stresses in parallel shaft spur gearing systems. It is seen that the outcomes gained from the modified drive have enhanced performance than the standard drive.


2006 ◽  
Vol 34 (4) ◽  
pp. 237-255 ◽  
Author(s):  
M. Kuwajima ◽  
M. Koishi ◽  
J. Sugimura

Abstract This paper describes experimental and analytical studies of the dependence of tire friction on the surface roughness of pavement. Abrasive papers were adopted as representative of the microscopic surface roughness of pavement surfaces. The rolling∕sliding friction of tire tread rubber against these abrasive papers were measured at low slip velocities. Experimental results indicated that rolling∕sliding frictional characteristics depended on the surface roughness. In order to examine the interfacial phenomena between rubber and the abrasive papers, real contact length, partial slip, and apparent friction coefficient under vertical load and tangential force were analyzed with two-dimensional explicit finite element analysis in which slip-velocity-dependent frictional coefficients were considered. Finite element method results indicated that the sum of real contact area and local partial slip were larger for finer surfaces under the same normal and tangential forces. In addition, the velocity-dependent friction enhanced local slip, where the dependence of local slip on surface roughness was pronounced. It proved that rolling∕sliding friction at low slip ratio was affected by local frictional behavior at microslip regions at asperity contacts.


Author(s):  
Manish Kumar ◽  
Pronab Roy ◽  
Kallol Khan

From the recent literature, it is revealed that pipe bend geometry deviates from the circular cross-section due to pipe bending process for any bend angle, and this deviation in the cross-section is defined as the initial geometric imperfection. This paper focuses on the determination of collapse moment of different angled pipe bends incorporated with initial geometric imperfection subjected to in-plane closing and opening bending moments. The three-dimensional finite element analysis is accounted for geometric as well as material nonlinearities. Python scripting is implemented for modeling the pipe bends with initial geometry imperfection. The twice-elastic-slope method is adopted to determine the collapse moments. From the results, it is observed that initial imperfection has significant impact on the collapse moment of pipe bends. It can be concluded that the effect of initial imperfection decreases with the decrease in bend angle from 150∘ to 45∘. Based on the finite element results, a simple collapse moment equation is proposed to predict the collapse moment for more accurate cross-section of the different angled pipe bends.


2011 ◽  
Vol 55-57 ◽  
pp. 664-669
Author(s):  
Jin Ning Nie ◽  
Hui Wang ◽  
De Feng Xie

According to the situation that the dual-friction drums on the new type towing machine lack stress analysis when designed, the safety is difficult to test and verify. The pull of wire rope in various positions was derived and calculated, so both compressive stress and tangent friction force generated by the pull of wire rope were calculated. The result made by ANSYS software demonstrates the safety of the left drum which suffers from larger loads, structure improvement measures are put forward for the drum.


2014 ◽  
Vol 672-674 ◽  
pp. 1550-1553
Author(s):  
Zhen Guo Shang ◽  
Zhong Chao Ma ◽  
Zhen Sheng Sun

A procedure for obtaining the load distribution in a four point contact wind turbine yaw bearing considering the effect of the structure’s elasticity is presented. The inhomogeneous stiffness of the supporting structures creates a variation in the results obtained with a rigid model. A finite element model substituting the rolling elements with nonlinear compression springs has been built to evaluate the effect of the supporting structure elasticity on the contact forces between the rolling elements and the raceways.


2012 ◽  
Vol 538-541 ◽  
pp. 3253-3258 ◽  
Author(s):  
Jun Jian Xiao

According to the results of finite element analysis (FEA), when the diameter of opening of the flat cover is no more than 0.5D (d≤0.5D), there is obvious stress concentration at the edge of opening, but only existed within the region of 2d. Increasing the thickness of flat covers could not relieve the stress concentration at the edge of opening. It is recommended that reinforcing element being installed within the region of 2d should be used. When the diameter of openings is larger than 0.5D (d>0.5D), conical or round angle transitions could be employed at connecting location, with which the edge stress decreased remarkably. However, the primary stress plus the secondary stress would be valued by 3[σ].


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