3D Nonlinear Contact FEM Analysis of U-Ring Seal Structure

2012 ◽  
Vol 510 ◽  
pp. 660-666
Author(s):  
Guo Qiang Chen ◽  
Jian Ping Tan ◽  
Xian Wang ◽  
Hui Chen

The U-ring reciprocating seal structure with high pressure was taken as research object; the nonlinear contact characteristics and failure mechanism of U-ring seal were analyzed. Finite element model was build through segmentation and sweep methods, Mooney-Rivlin model was selected to characterize the rubber material, the Generalized Lagrange Multiplier Method were designed as contact algorithm. Based on LS-DYNA software, the 3D nonlinear dynamic simulations of U-ring seal structure were realized under different conditions. The results shows that the maximum contact stress steady increased with the growth of medium pressure, relative velocity, and friction coefficient, the top of inner lip and the circle of bottom hole were the main sites of contact stress concentrated on, the reverse velocity of valve stem is the main factor impact too large contact stress and seal damage. The simulation conclusions were verified by comparing the characteristics of actual seal failure.

2013 ◽  
Vol 470 ◽  
pp. 371-375 ◽  
Author(s):  
Shao Hua Chen ◽  
Guo Zhang Jiang ◽  
Gong Fa Li ◽  
Liang Xi Xie ◽  
Wen Qiang Qian

The two-dimensional O-ring seal nonlinear axisymmetric finite element model are established which is used for swinging hydraulic cylinder. Some factors influencing rubber O-ring sealing performance were taken into account, such as rotating shaft diameter, O-ring seal section diameter. The results indicate that when medium pressure is zero, the two factors influence Von Mises and maximum contact stress of sealing face greatly. Under medium pressure (P=10Mpa), the two factors have a little influence to Von Mises and maximum contact stress.


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.


2014 ◽  
Vol 30 (4) ◽  
pp. 373-382 ◽  
Author(s):  
R.-Z. Wang ◽  
S.-K. Chen ◽  
K.-Y. Liu ◽  
C.-Y. Wang ◽  
K.-C. Chang ◽  
...  

AbstractIn this paper, analytical simulations of the steel-laminated elastomeric bearing (SLEB) using a three-dimensional (3D) finite element model incorporating material, geometric nonlinearities, and a frictional contact algorithm in LS-DYNA code is conducted. In order to simulate the nonlinear responses of the elastomeric bearing under the compression and shear, a hyperviscoelastic rubber model such as The MAT_77_H (MAT_HYPERVISCOELASTIC_RUBBER) in LS- DYNA code is adopted. Based on the proposed material model for the SLEB, the interaction effects of the SLEB under compression, bending, and torsion are analyzed. Analytical results are compared with the test results of the SLEBs. A set of material parameters is proposed for 3D FEM analysis of SLEBs. The proposed material model demonstrates its accuracy.


Author(s):  
Fuying Zhang ◽  
Haoche Shui ◽  
Jun-Mei Yang

The finite element model of four packer rubber materials was established by using ABAQUS and FE-SAFE software. The initial sealing load (the load is the pressure) was 11.85 MPa, and the working load was 58.15 MPa. The sealing evaluation coefficient, maximum contact stress, and fatigue life value of four material packer rubbers were considered when considering temperature changes and fatigue unit nodes. The results show that when the working load and the structural parameters of the rubber are the same, the sealing evaluation coefficient of the four material rubber increases with the increase of temperature. When the working temperature reaches 125 ℃, the value of the rubber seal evaluation coefficient of the HNBR material is the largest, and the value of the rubber seal evaluation coefficient of the EPDM material is the smallest. Similarly, the maximum contact stress of the four material rubbers increases with increasing temperature. When the temperature reaches 125 ℃, the maximum contact stress of the HNBR material is the largest, and the maximum contact stress of the EPDM material is the smallest. The rubber of the four materials increase the fatigue life value with the increase in the temperature within the operating temperature range studied. When the temperature is lower than 120 ℃, the fatigue life value of the HNBR material rubber is the largest. When the temperature is higher than 120 ℃, the fatigue life value of the CR material rubber is the largest. Regardless of the temperature change, the fatigue life value of the EPDM is the smallest. By comparing the results of field experiments with the results of finite element models, the two are found to have good consistency, which verifies the validity and feasibility of the model. The research results have important guiding significance for the fatigue life prediction of various material packer rubbers under different temperatures.


1995 ◽  
Vol 117 (4) ◽  
pp. 602-606 ◽  
Author(s):  
Tae Gun Jeong ◽  
D. B. Bogy

In order to estimate the contact stress and deformation at the instant of head-disk impact during dynamic loading, Hertz’s impact theory is implemented in a dynamic loading numerical simulator. By using a finite difference model for the air bearing, a finite element model for the slider-flexure-suspension system, and Hertz’s contact model of head-disk impact, we obtain estimates of contact stress, area and time through simulation of the dynamic loading process. With our choice of the material properties and geometric configurations, the duration of sliding contact is about 7 μs, the maximum width of contact is about 10 μm, and the maximum contact stress is about 620 MPa. This is below the yield stresses of the chosen media.


2012 ◽  
Vol 468-471 ◽  
pp. 2374-2380
Author(s):  
Zhen Xing Zheng ◽  
Hua Wei Zhang ◽  
Zhi Heng Wu ◽  
You Yan Jing

The nonlinear contact mathematic model is constructed for the bolt joint structure on the fixed end of the Gelin column of die casting machinery and the FEM model and optimization mathematic model for the bolt joint structure are realized by software of ANSYS and the APDL language embedded in it. The structural parameters of different type of thread in Gelin column are optimized. After the comparison of equivalent contact stress in the region of the different type of the bolt joint in Gelin column, it is shown that there is more even load-bearing characteristics with the trapezoidal thread than zigzag thread and the maximum of the equivalent contact stress with the trapezoidal thread is decreased about 41% of that in zigzag thread which can effectively improve lifecycle and anti-fatigue performance of the threaded joint in the gelin column.


1971 ◽  
Vol 38 (3) ◽  
pp. 608-614 ◽  
Author(s):  
Y. C. Pao ◽  
Ting-Shu Wu ◽  
Y. P. Chiu

This paper is concerned with the plane-strain problem of an elastic layer supported on a half-space foundation and indented by a cylinder. A study is presented of the effect of the contact condition at the layer-foundation interface on the contact stresses of the indented layer. For the general problem of elastic indenter or elastic foundation, the integral equations governing the contact stress distribution of the indented layer derived on the basis of two-dimensional theory of elasticity are given and a numerical method of solution is formulated. The limiting contact conditions at the layer-foundation interface are then investigated by considering two extreme cases, one with the indented layer in frictionless contact with the half space and the other with the indented layer rigidly adhered to the half space. Graphs of the bounds on the maximum normal stress occurring in indented elastic layers for the cases of rigid cylindrical indenter and rigid half-space foundation are obtained for possible practical applications. Some results of the elastic indenter problem are also presented and discussed.


Author(s):  
T Stewart ◽  
Z M Jin ◽  
D Shaw ◽  
D D Auger ◽  
M Stone ◽  
...  

The tibio-femoral contact area in five current popular total knee joint replacements has been measured using pressure-sensitive film under a normal load of 2.5 kN and at several angles of flexion The corresponding maximum contact pressure has been estimated from the measured contact areas and found to exceed the point at which plastic deformation is expected in the ultra-high molecular weight polyethylene (UHMWPE) component particularly at flexion angles near 90°. The measured contact area and the estimated maximum contact stress have been found to be similar in magnitude for all of the five knee joint replacements tested. A significant difference, however, has been found in maximum contact pressure predicted from linear elasticity analysis for the different knee joints. This indicates that varying amounts of plastic deformation occurred in the polyethylene component in the different knee designs. It is important to know the extent of damage as knees with large amounts of plastic deformation are more likely to suffer low cycle fatigue failure. It is therefore concluded that the measurement of contact areas alone can be misleading in the design of and deformation in total knee joint replacements. It is important to modify geometries to reduce the maximum contact stress as predicted from the linear elasticity analysis, to below the linear elastic limit of the plastic component.


Author(s):  
N. Bosso ◽  
A. Gugliotta ◽  
N. Zampieri

Determination of contact forces exchanged between wheel and rail is one of the most important topics in railway dynamics. Recent studies are oriented to improve the existing contact methods in terms of computational efficiency on one side and on the other side to develop more complex and precise representation of the contact problem. This work shows some new results of the contact code developed at Politecnico di Torino identified as RTCONTACT; this code, which is an improvement of the CONPOL algorithm, is the result of long term activities, early versions were used in conjunction with MBS codes or in Matlab® environment to simulate vehicle behaviour. The code has been improved also using experimental tests performed on a scaled roller-rig. More recently the contact model was improved in order to obtain a higher computational efficiency that is a required for the use inside of a Real Time process. Benefit of a Real Time contact algorithm is the possibility to use complex simulation models in diagnostic or control systems in order to improve their performances. This work shows several comparisons of the RTCONTACT contact code respect commercial codes, standards and benchmark results.


2012 ◽  
Vol 268-270 ◽  
pp. 737-740
Author(s):  
Yang Yu ◽  
Yi Hua Dou ◽  
Fu Xiang Zhang ◽  
Xiang Tong Yang

It is necessary to know the connecting and sealing ability of premium connection for appropriate choices of different working conditions. By finite element method, the finite element model of premium connection is established and the stresses of seal section, shoulder zone and thread surface of tubing by axial tensile loads are analyzed. The results show that shoulder zone is subject to most axial stresses at made-up state, which will make distribution of stresses on thread reasonable. With the increase of axial tensile loads, stresses of thread on both ends increase and on seal section and shoulder zone slightly change. The maximum stress on some thread exceed the yield limit of material when axial tensile loads exceed 400KN. Limited axial tensile loads sharply influence the contact pressures on shoulder zone while slightly on seal section. Although the maximum contact pressure on shoulder zone drop to 0 when the axial tensile load is 600KN, the maximum contact pressure on seal section will keep on a high level.


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