Determination of Contact Stiffness of Rod-Fastened Rotors Based on Modal Test and Finite Element Analysis

Author(s):  
Yanchun Zhang ◽  
Zhaogang Du ◽  
Liming Shi ◽  
Shaoquan Liu

A series of simplified rod-fastened rotors, which have different surface contact roughness are manufactured and their modal parameters under different pretightening force, are measured in free-free state. The concept of surface contact stiffness is introduced to simulate the influence of pretightening force on modal parameters of these simplified rod-fastened rotors using finite element method. The experiment measured results are compared and fitted to the finite element analysis results and the relationship between contact stiffness and contact stress is established in which the contact stress is defined by the pretightening force. The relationship is then applied on the modal analysis of a real gas turbine rotor, and its modal test results and finite element analysis results are consistent with each other, proving that the relationship and the described determination method of contact stiffness based on modal test and finite element analysis are effective.

2011 ◽  
Vol 314-316 ◽  
pp. 1218-1221
Author(s):  
Hao Min Huang

Conventional methods of design to be completed ordinary hydraulic transmission gear gearbox design, but for such a non-planet-rule entity, and the deformation of the planet-gear contact stress will have a great impact on the planet gear, it will be very difficult According to conventional design. In this paper, ANSYS software to the situation finite element analysis, the planetary gear to simulate modeling study.


2014 ◽  
Vol 496-500 ◽  
pp. 1007-1011
Author(s):  
Jian Hua Fang ◽  
Wei Yan

The design of seal device that can be used in carbide actor is a real problems.This paper presents a kind of oblique-cone-slid-ring (OCSR) assembly seal device that can self-compensate the seal wear in application. The max contact stress on the seal surface and other contact face is far bigger than the work stress of sealed medium in carbide actor. That means the design satisfies the user demand . Keywords: oblique-cone-sliding-ring (OCSR) assembly seal; self-compensation to seal wear; finite element analysis; contact stress;


2014 ◽  
Vol 633-634 ◽  
pp. 693-698
Author(s):  
Long Xin ◽  
Shi Chao Cui ◽  
Qi Lin Shu

In this paper, the ram of boring and milling machining center is taken as the research object. A new method that hydraulic pull rods compensation is proposed to solve the problem of deformation compensation of long stroke ram of boring and milling machining center. Firstly, the method of finite element analysis is used to get the laws of ram deformation and the relationship curve between the ram deformation and the stroke of ram. Secondly, the preliminary calculation value of pull rods compensation force is derived based on the theoretical analysis of material mechanics. The relationship curve between compensation force and the stroke of ram is obtained by finite element analysis and polynomial least squares method. Finally, the analyzed results are as follows: the laws of ram deformation distribution is accurately predicted by the used method, the deflection error of the ram is well controlled,and the machining precision is significantly improved.


2021 ◽  
pp. 1-14
Author(s):  
Xiaodong Chen ◽  
ZM Xie ◽  
Huifeng Tan

Abstract How to enlarge the output displacement is a key issue in the research field of microgrippers. It is difficult to further enlarge the output displacement for the traditional displacement transmission mechanism (DTM). In this research, a two-stage amplification cylinder-driven DTM based on the compliant mechanisms is designed to realize the displacement output expansion. The opening and closing of the clamping jaws is driven by the air cylinder to enlarge the output displacement of the microgripper. According to the analysis of statics model of the mechanism, the relationship between the output displacement of the microgripper and the driving pressure of the cylinder is established. The magnification of the microgripper is obtained using a dynamic model. Moreover, based on the finite element analysis, the mechanical structure parameters are optimized. The microgripper was fabricated by utilizing wire electro discharge machining (WEDM) technique, and then a series of experiments were carried out to obtain the relationship between the displacement and the driving pressure. It is found that the maximum output displacement measured is 1190.4μm under the pressure of 0-0.6 Mpa, corresponding to the magnification of 47.63. Compared with the results of finite element analysis and theoretical calculation, the test results have a discrepancy of 2.39% and 6.62%, respectively. The microgripper has successfully grasped a variety of micro-parts with irregular shapes, and parallel grasping can be achieved, demonstrating the potential application of this design in the field of micromanipulation.


2013 ◽  
Vol 442 ◽  
pp. 229-232 ◽  
Author(s):  
Li Mei Wu ◽  
Fei Yang

According to the cutting theory of involute tooth profile, established an exact three-dimensional parametric model by UG. Used ABAQUS to crate finite element model for gear meshing. After simulated the meshing process, discussed the periodicity of the tooth surface contact stress. Based on the result of finite element analysis, made a comparison of the maximum contact stress between finite element solution and Hertz theoretical solution, analyzed the contact stress distribution on tooth width, and researched the effect of friction factor on contact stress. All that provided some theoretical basis for gear contact strength design.


1970 ◽  
Vol 40 (2) ◽  
pp. 137-141
Author(s):  
R. Nagendra Babu ◽  
K. V. Ramana ◽  
K. Mallikarjuna Rao

Stress Concentration Factors are significant in machine design as it gives rise to localized stress when any change in the design of surface or abrupt change in the cross section occurs. Almost all machine components and structural members contain some form of geometrical or microstructural discontinuities. These discontinuities are very dangerous and lead to failure. So, it is very much essential to analyze the stress concentration factors for critical applications like Turbine Rotors. In this paper Finite Element Analysis (FEA) with extremely fine mesh in the vicinity of the blades of Steam Turbine Rotor is applied to determine stress concentration factors.Keywords: Stress Concentration Factors; FiniteElement Analysis; ANSYS.DOI: 10.3329/jme.v40i2.5355Journal of Mechanical Engineering, Vol. ME 40, No. 2, December 2009 137-141


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