The effect of proximity of a rail end in elastic-plastic contact between a wheel and a rail

2003 ◽  
Vol 217 (3) ◽  
pp. 189-201 ◽  
Author(s):  
Y. C. Chen
Keyword(s):  
Contact Stress ◽  
Contact Point ◽  
Plastic Zone Size ◽  
Von Mises Stress ◽  
Stress Distributions ◽  
Elastic Plastic ◽  
Contact Points ◽  
Contact Distance ◽  
Von Mises ◽  
Strain Model

This paper investigates the effects of a free rail end on the contact stress distribution near the rail end by employing elastic-plastic finite element methods. The contact elements were used to simulate the interaction between a wheel and a rail. A plane strain model was used in this study. Variations in contact stress fields at various contact points near the rail end were compared. The availability of the Hertz contact theory in the region near the rail end was also investigated. The numerical results indicated that the contact stress distributions around the rail end are sensitive to the contact distance. The location of the maximum von Mises stress was shifted to the contact surface as the contact point moves close to the rail end. Results also show that the plastic zone size and the von Mises stress are increased gradually and extend to the rail end as the contact point moves near the rail end. A higher stress, larger deflection and serious plastic deformation occurring at the rail end may lead to deterioration and delamination at the rail end.

Numerical Study on Elastic-Plastic Stress Field Near the Cooling Holes of Nickel-Based Single Crystal Air-Cooled Blades

2006 ◽  
Vol 324-325 ◽  
pp. 563-566 ◽  
Author(s):  
Qing Min Yu ◽  
Zhu Feng Yue ◽  
Yong Shou Liu
Keyword(s):  
Shear Stress ◽  
Stress Field ◽  
Numerical Study ◽  
Von Mises Stress ◽  
Shear Stresses ◽  
Slip Systems ◽  
Stress Distributions ◽  
Elastic Plastic ◽  
Von Mises ◽  
Plastic Stress

In this paper, a plate containing a central hole was used to simulate gas turbine blade with cooling hole. Numerical calculations based on crystal plasticity theory have been performed to study the elastic-plastic stress field near the hole under tension. Two crystallographic orientations [001] and [111] were considered. The distributions of resolved shear stresses and strains of the octahedral slip systems {110}<112> were calculated. The results show that the crystallographic orientation has remarkable influence on both von Mises stress and resolved shear stress distributions. The resolved shear stress distributions around the hole are different between the two orientations, which lead to the different activated slip systems. So the deformed shape of the hole in [001] orientation differs from that in [111] orientation.

Torque and Stress Characteristics of the Skewed-Roller Slipping Clutch Considering Frictional Contact and Dynamic Equilibrium

2014 ◽  
Vol 670-671 ◽  
pp. 784-789
Author(s):  
Ming Feng ◽  
Yong Li
Keyword(s):  
Contact Stress ◽  
Frictional Contact ◽  
Dynamic Equilibrium ◽  
Von Mises Stress ◽  
Relative Rotation ◽  
Stress Distributions ◽  
Surface Contact ◽  
Von Mises

The Skewed–Roller Slipping Clutch (SRSC) produces resistant torque which depends on the relative rotation and sliding between askew arranged cylindrical rollers and specially curved races. In this paper, the surface contact stress and von Mises stress distributions between the dub-off profiled rollers and races are calculated, with consideration given to the frictional contact and dynamic equilibrium of the rollers. The effects of the profiled roller’s parameters on the von Mises stress are investigated and the optimal modification parameters are calculated. In addition, the limiting resistant torque characteristics of the slipping clutch with optimal profiled rollers are discussed in detail.

Elastic-Plastic Partial Slip Rolling Wheel-Rail Contact with an Oblique Rail Crack

2005 ◽  
Vol 127 (4) ◽  
pp. 705-712 ◽  
Author(s):  
Yung-Chuan Chen ◽  
Jao-Hwa Kuang
Keyword(s):  
Friction Force ◽  
Contact Stress ◽  
Surface Friction ◽  
Element Model ◽  
Partial Slip ◽  
Stress Distributions ◽  
Tractive Force ◽  
Plastic Energy ◽  
Elastic Plastic ◽  
Contact Distance

This study employs an elastic-plastic finite element model to investigate the effect of oblique rail surface crack on the wheel-rail contact stress distribution under partial slip rolling conditions. Numerical simulations are performed to explore the effects of the contact distance and tractive force on the contact pressure and tangential stress distributions, tip plastic energy, and critical wheel applied load. Contact elements are used to simulate the interaction between the surfaces of the wheel rail and the crack. The numerical results indicate that the contact stress distributions are influenced significantly by the presence of oblique cracks in the rail. The results also indicate that a higher friction force is induced on the crack surfaces when a greater tractive force is applied to the wheel. This increased crack surface friction force reduces the sliding between the crack surfaces and hence causes a reduction in the tip plastic energy.

Elastic-Plastic Contact Analysis of Materials with Gradient Yield Strength

2006 ◽  
Vol 532-533 ◽  
pp. 881-884
Author(s):  
Qin Xie ◽  
Geng Liu ◽  
Tian Xiang Liu ◽  
Jane Q. Wang
Keyword(s):  
Yield Strength ◽  
Yield Criterion ◽  
Contact Model ◽  
Von Mises Stress ◽  
Stress Distributions ◽  
Initial Stiffness ◽  
Programming Technique ◽  
Elastic Plastic ◽  
Von Mises ◽  
Yield Strength Variation

Reported in the paper is an elastic-plastic contact model developed to analyze the contact performance characteristics of materials with gradient yield strength. Plastic yielding and the strain-hardening properties of the materials are taken into account. The finite element method, the initial stiffness method, and a mathematical programming technique are utilized to solve the contact model. The von Mises yield criterion is used to determine the inception of plastic deformation. Results indicate that nitrided material with appropriate gradient of yield strength may greatly alter the distributions of contact stress, contact pressure as compared with untreated material in contact. The effects of different yield strength variation path of material on von Mises stress distributions are numerically investigated and discussed.

Effects of occlusal scheme on All-on-Four abutments, screws and prostheses: A three-dimensional finite element study

2020 ◽  
Author(s):  
Nurullah Türker ◽  
Hümeyra Tercanlı Alkış ◽  
Steven J Sadowsky ◽  
Ulviye Şebnem Büyükkaplan
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Good Prognosis ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Group Function ◽  
Occlusal Contact ◽  
Maximum Deformation ◽  
Contact Points ◽  
Von Mises

An ideal occlusal scheme plays an important role in a good prognosis of All-on-Four applications, as it does for other implant therapies, due to the potential impact of occlusal loads on implant prosthetic components. The aim of the present three-dimensional (3D) finite element analysis (FEA) study was to investigate the stresses on abutments, screws and prostheses that are generated by occlusal loads via different occlusal schemes in the All-on-Four concept. Three-dimensional models of the maxilla, mandible, implants, implant substructures and prostheses were designed according to the All-on-Four concept. Forces were applied from the occlusal contact points formed in maximum intercuspation and eccentric movements in canine guidance occlusion (CGO), group function occlusion (GFO) and lingualized occlusion (LO). The von Mises stress values for abutment and screws and deformation values for prostheses were obtained and results were evaluated comparatively. It was observed that the stresses on screws and abutments were more evenly distributed in GFO. Maximum deformation values for prosthesis were observed in the CFO model for lateral movement both in the maxilla and mandible. Within the limits of the present study, GFO may be suggested to reduce stresses on screws, abutments and prostheses in the All-on-Four concept.

Investigation on stress distribution and pressure capacity of two-layer split high-pressure die based on finite element analysis

2019 ◽  
Vol 233 (14) ◽  
pp. 5048-5055
Author(s):  
Z Yi ◽  
WZ Fu ◽  
MZ Li
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Pressure ◽  
Stress State ◽  
Von Mises Stress ◽  
Stress Distributions ◽  
Element Analysis ◽  
Round Cylinder ◽  
Von Mises ◽  
Supporting Ring

In order to obtain a higher pressure capacity for the high-pressure die with a larger sample cavity, two types of two-layer split dies with a round cylinder and a quadrate cylinder were designed based on the conventional belt-type die. Finite element analysis was performed to investigate the stress distributions and pressure capacities of the high-pressure dies using a derived Mohr–Coulomb criterion and the von Mises criterion for the cylinder and supporting rings, respectively. As predicted by the finite element analysis results, in the two-layer split dies with a round cylinder, the stress state of the cylinder can be only slightly improved; and the von Mises stress of the first layer supporting ring can be hardly decreased. However, in the two-layer split dies with a quadrate cylinder and sample cavity, the stress state of the cylinder can be remarkably improved. Simultaneously, the von Mises stress of the supporting rings, especially for the first-layer supporting ring, can be also effectively decreased. The pressure capacities of the two-layer split dies with a round cylinder and a quadrate cylinder are 16.5% and 63.9% higher with respect to the conventional belt-type die.

scholarly journals Effect of Fiber Posts on Stress Distribution of Endodontically Treated Upper Premolars: Finite Element Analysis

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1708 ◽  
Author(s):  
Maciej Zarow ◽  
Mirco Vadini ◽  
Agnieszka Chojnacka-Brozek ◽  
Katarzyna Szczeklik ◽  
Grzegorz Milewski ◽  
...  
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Resin Composite ◽  
Von Mises Stress ◽  
Stress Distributions ◽  
Stress Concentrations ◽  
Element Analysis ◽  
Endodontically Treated Tooth ◽  
Maxillary Premolars ◽  
Von Mises

By means of a finite element method (FEM), the present study evaluated the effect of fiber post (FP) placement on the stress distribution occurring in endodontically treated upper first premolars (UFPs) with mesial–occlusal–distal (MOD) nanohybrid composite restorations under subcritical static load. FEM models were created to simulate four different clinical situations involving endodontically treated UFPs with MOD cavities restored with one of the following: composite resin; composite and one FP in the palatal root; composite and one FP in the buccal root; or composite and two FPs. As control, the model of an intact UFP was included. A simulated load of 150 N was applied. Stress distribution was observed on each model surface, on the mid buccal–palatal plane, and on two horizontal planes (at cervical and root-furcation levels); the maximum Von Mises stress values were calculated. All analyses were replicated three times, using the mechanical parameters from three different nanohybrid resin composite restorative materials. In the presence of FPs, the maximum stress values recorded on dentin (in cervical and root-furcation areas) appeared slightly reduced, compared to the endodontically treated tooth restored with no post; in the same areas, the overall Von Mises maps revealed more favorable stress distributions. FPs in maxillary premolars with MOD cavities can lead to a positive redistribution of potentially dangerous stress concentrations away from the cervical and the root-furcation dentin.

Design and Analysis on a Kind of Oblique-Cone-Slid-Ring Assembly Seal Device with Self-Compensation to Seal Wear in Carbide Actor

2010 ◽  
Vol 43 ◽  
pp. 247-252 ◽  
Author(s):  
Yong Hu ◽  
Wei Yan ◽  
Hua Bing Wen ◽  
Chuan Shun Wen
Keyword(s):  
Work Stress ◽  
Contact Stress ◽  
Von Mises Stress ◽  
Thickness Variation ◽  
Ansys Software ◽  
Ring Assembly ◽  
Spring Force ◽  
User Demand ◽  
Von Mises ◽  
Oblique Cone

We design and analyze a kind of oblique-cone-slid-ring (OCSR) assembly seal device used in carbide actor that can self-compensate the seal wear. The effect of the OCSR thickness variation on the contact stress, Von mises stress, and spring force is analyzed using ANSYS software. It shows that the OCSR assembly seal device can seal well and has the function of self-compensation to seal wear when the OCSR thickness vary during the experiment conditions given. The max contact stress on the seal surface and other contact face is higher or much higher than the work stress of sealed medium. That means the design is satisfied with the user demand. The results provide a theoretical base for the further study and applications of the OCSR assembly seal device.

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