A new incremental calculated approach to predict maximum contact stress of compressed packer in large deformation

2021 ◽  
pp. 095440622110305
Author(s):  
Peng Fan ◽  
Yuchun Kuang ◽  
Bo Yang
Keyword(s):  
Mathematical Model ◽  
Large Deformation ◽  
Contact Stress ◽  
Reference Value ◽  
Thick Wall ◽  
Contact Friction ◽  
Rubber Tube ◽  
Maximum Contact Stress ◽  
Deformation Processes ◽  
Maximum Contact

Compressed packer rubber is large deformation material, which endures biaxial contact friction between oil-pipe and casing-pipe in sitting and sealing process. Large-deformation theory analysis of rubber brings huge difficulties to solve, this is due to the material, geometry and contact non-linearity should be considered. In this article, the deformation of compressed packer rubber tube (CPRT) is divided into free deformation, unidirectional and bidirectional constrained deformations. Based on the theory of thick-wall-cylinder and the linear constitutive of rubber material segment, the CPRT mathematical model in different deformation processes is established and the influences of axial load, axial height of CPRT and contact friction coefficient of casing inner wall etc are considered. Based on incremental calculated approach, the mathematical model is solved. By comparing the results of the theoretical model with the results of finite element method and experimental results, it is found that the theoretical maximum contact stress is more conservative than the FEM and experimental solutions, so the sealing reliability of packer effectively predicted under the premise of allowable contact stress and the theoretical results can provide a lower limit reference value for the contact stress of the packer in the actual seal process. Meanwhile, the deviation of contact stress in FEM and theoretical value at z150 height of CPRT is among 1.13%∼4.90%, which can predict the contact stress in the compressed area near the stress concentration upper end-face of CPRT under the low friction factor, the results provide a reference for the compressed packer design.

scholarly journals Development of a nomogram to predict the contact stress between an I-girder and a support roller

2021 ◽  
Vol 9 (4) ◽  
pp. 377-390 ◽  
Author(s):  
Thanin Chanmalai ◽  
Byungik Chang ◽  
Kevin Misaro ◽  
Saron Hagos ◽  
Thippesh Bethur Hanumanthareddy
Keyword(s):  
Numerical Modeling ◽  
Contact Stress ◽  
Contact Stresses ◽  
Primary Objective ◽  
Steel Bridge ◽  
Element Analysis ◽  
Maximum Contact Stress ◽  
Environmentally Sensitive Areas ◽  
Support Roller ◽  
Maximum Contact

The incremental launching method (ILM) is an efficient method of bridge construction primarily suited for environmentally sensitive areas. However, during the bridge launching, there are significant contact stresses between the launching system and the steel bridge girders. These substantial contact stresses can cause damage both on, and just under, the girder surface. Although Hertz contact theory solutions may give an insight into the problem, the accuracy is uncertain due to the presence of complex geometries, loads, and material properties. The complicated structural systems need to rely on numerical modeling such as the finite element analysis which are not always available. The primary objective of this study is to estimate the relationship of the maximum contact stress between an I-girder and a roller using a nomogram. The nomogram is built based on a parametric study with various roller dimensions and loads by numerical modeling. The maximum contact stress from the nomogram can be a useful tool in designing a bridge girder on a support roller.

Contact Stress in a Gerotor Pump

2003 ◽  
Author(s):  
P. Javier Gamez-Montero ◽  
Esteve Codina
Keyword(s):  
Contact Stress ◽  
Measurement Techniques ◽  
Design Parameters ◽  
Prototype Model ◽  
Gear Pump ◽  
Gear Teeth ◽  
2D Simulation ◽  
Maximum Contact Stress ◽  
Gerotor Pump ◽  
Maximum Contact

The aim of the first part of this paper is to reach the optimum design parameters of a gear set when it works as part of an internal gear pump type gerotor. The performance of the gear teeth and the whole gear set are evaluated through analytical studies to obtain the maximum contact stress in gear teethe and the volumetric characteristics. Several gear sets have been examined and the results are presented. The aim of the second part of the this paper is to documents a better understanding of the performance of a crankshaft mounted gerotor pump for IC engines lubrication. Modeling, simulation and experimental work have been examined for a specific unit. A preliminary 2D simulation is carried out by using the Finite Element Method (FEX) to calculate the maximum contact stress. At the testing phase, a prototype model of the gear set provides the maximum contact stress on a pair of teeth by using photoelasticity measurement techniques. The results are exposed and discussed and possible alterations are proposed.

Validation of a Finite Element Humeroradial Joint Model of Contact Pressure Using Fuji Pressure Sensitive Film

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Sunghwan Kim ◽  
Mark Carl Miller
Keyword(s):  
Finite Element ◽  
Contact Stress ◽  
Contact Area ◽  
Axial Loads ◽  
Contact Areas ◽  
Pressure Sensitive ◽  
Maximum Contact Stress ◽  
Sensitive Film ◽  
Pressure Sensitive Film ◽  
Maximum Contact

A finite element (FE) elbow model was developed to predict the contact stress and contact area of the native humeroradial joint. The model was validated using Fuji pressure sensitive film with cadaveric elbows for which axial loads of 50, 100, and 200 N were applied through the radial head. Maximum contact stresses ranged from 1.7 to 4.32 MPa by FE predictions and from 1.34 to 3.84 MPa by pressure sensitive film measurement while contact areas extended from 39.33 to 77.86 mm2 and 29.73 to 83.34 mm2 by FE prediction and experimental measurement, respectively. Measurements from cadaveric testing and FE predictions showed the same patterns in both the maximum contact stress and contact area, as another demonstration of agreement. While measured contact pressures and contact areas validated the FE predictions, computed maximum stresses and contact area tended to overestimate the maximum contact stress and contact area.

The Effects of Load on the Radial Bearing Properties of Pre-Loaded Cylindrical Roller Bearings

2011 ◽  
Vol 130-134 ◽  
pp. 2306-2310
Author(s):  
Yan Gang Wei ◽  
Meng Sun
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Contact Stress ◽  
Radial Load ◽  
The Finite Element Method ◽  
Roller Bearings ◽  
Radial Stiffness ◽  
Maximum Contact Stress ◽  
Maximum Contact ◽  
Cylindrical Roller

According to the theory of contact mechanics, the radial stiffness, the maximum contact stress, and the maximum radial load of pre-loaded cylindrical roller bearings, including both solid roller and hollow roller bearings, are calculated with the finite element method. The effects of load on the radial stiffness, the maximum contact stress, and the maximum radial load of bearing are analyzed. The analysis results show that the effect of load on the radial stiffness is complex. Under the different magnitude loads, the effects of both hollowness and interference magnitude on the radial stiffness and on the maximum contact stress are not same. Thus the effects of load magnitude must be considered in the design and application of pre-loaded cylindrical roller bearings.

Sealing performance and fatigue life of the fracturing packer rubber of various materials

2019 ◽  
Vol 233 (17) ◽  
pp. 6157-6166 ◽  
Author(s):  
Fuying Zhang ◽  
Haoche Shui ◽  
Jun-Mei Yang
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Contact Stress ◽  
Field Experiments ◽  
Structural Parameters ◽  
Element Model ◽  
Rubber Seal ◽  
Maximum Contact Stress ◽  
Different Temperatures ◽  
Maximum Contact

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.

scholarly journals Analytical Calculation of the Tooth Surface Contact Stress of Cylindrical Gear with Variable Hyperbolic Circular-Arc-Tooth-Trace

Symmetry ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1318
Author(s):  
Yongqiao Wei ◽  
Rui Guo ◽  
Yongping Liu ◽  
Changbin Dong ◽  
Dawei Li ◽  
...  
Keyword(s):  
Contact Stress ◽  
Contact Fatigue ◽  
Tooth Surface ◽  
Element Analysis ◽  
Cylindrical Gear ◽  
Circular Arc ◽  
Contact Fatigue Strength ◽  
Maximum Contact Stress ◽  
Tooth Width ◽  
Maximum Contact

In order to theoretically research the tooth surface maximum contact stress of a Cylindrical Gear with Variable Hyperbolic Circular-Arc-Tooth-Trace (VH-CATT), the computing formula of maximum contact stress of VH-CATT cylindrical gear is investigated according to Hertz formula in this paper. Insufficient contact fatigue strength will lead to pitting corrosion, plastic deformation of tooth surface and other damages. Therefore, the maximum contact stress of tooth surface must be carried out. The contact stress calculation formula is particularly considering the effect of normal force, total carrying length, synthetical curvature radius, and position angle. The present work establishes analytical solutions to research the effect of different parameters for the contact stress of VH-CATT cylindrical gear incorporating elastic deformation on the tooth surface, and which have shown that the different module, transmission ratio, pressure angle, tooth width, and the cutter head radius have a crucial effect on the contact stress and contact ellipse of VH-CATT cylindrical gear along the tooth width direction. Moreover, a finite element analysis is carried out to verify the correctness of the theoretical computing formula of contact stress of VH-CATT cylindrical gear. By contrast with the theoretical calculated value and the stress value of finite element analysis, its error is very small. It is indicated that the derived formula of contact fatigue strength of VH-CATT cylindrical gear has high accuracy and can accurately reflect the real contact stress value of tooth surface, which is beneficial for research on tooth break reduction, pitting, wear resistance and fatigue life improvement of the VH-CATT cylindrical gear. The study results also have a certain reference value for the design and check calculation of the VH-CATT cylindrical gear.

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