scholarly journals Influence of Full-Life Cycle Wheel Profile on the Contact Performance of Wheel and Standard Fixed Frog in Heavy Haul Railway

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
He Ma ◽  
Jinming Zhang ◽  
Jun Zhang ◽  
Tao Tao Jin ◽  
Chun Yu Song
Keyword(s):  
Contact Force ◽  
Lateral Displacement ◽  
Dynamic Interaction ◽  
Von Mises Stress ◽  
Static Contact ◽  
Heavy Haul ◽  
Wheel Profile ◽  
Wheel Profile Wear ◽  
Von Mises ◽  
Heavy Haul Railway

Wheel wear is unavoidable, which affects the contact performance of the wheel and rail. This article explores the effects of wheel profile wear on the static contact and dynamic interaction between wheel and standard fixed frog in heavy haul railway. The coupling dynamic models of the vehicle-fixed frog system are established to calculate the change regulation of displacement, contact force, and acceleration when a vehicle passes through the standard fixed frog at a speed of 50 km/h in the facing move in the diverging line. Besides, the finite element models of wheel and standard fixed frog at key positions are developed to simulate the contact patch and distribution of von Mises stress in the regions of the wheel-fixed frog. Compared with the standard profile, the maximum lateral displacement of the worn profile can be reduced by up to 9 mm. The vertical contact force can be reduced from 750 kN to 320 kN, and the decrease is 57.3%. The von Mises stress could decrease up to 34% compared with the standard. And the results show that the wheel profile wear changes the positions of the wheel-rail contact points along the longitudinal direction and affects the dynamic interaction of vehicle and standard fixed frog. For the measured worn wheel profiles in this article, profile wear relieves the dynamic responses and it is good for the nose rail.

Influence of Rail Cant on Wheel-Rail Contact Relationship and Dynamic Performance in Curves for Heavy Haul Railway

2013 ◽  
Vol 365-366 ◽  
pp. 381-387
Author(s):  
Pu Wang ◽  
Liang Gao ◽  
Bo Wen Hou
Keyword(s):  
Contact Angle ◽  
Single Point ◽  
Point Contact ◽  
Contact Geometry ◽  
Dynamic Interaction ◽  
Track Geometry ◽  
Static Contact ◽  
Heavy Haul ◽  
Heavy Haul Railway ◽  
Angle Parameter

Rail cant is one of the most important track geometry parameters, which can change the wheel-rail contact relationship and then influence the dynamic interaction. Static contact geometry parameters for 75kg/m rail in contact with LM wheel tread under different rail cants are analyzed on the basis of the wheel-rail spatial contact geometry algorithm. A train (multi-vehicle)-track coupling dynamic model is established with the help of the software Universal Mechanism (UM), and dynamic performances of train-track system in curves are compared under different rail cants. The results indicate that: (1) flange contact is less likely to occur under 1/20 rail cant, which will reduce uneven wear of wheel/rail tread. (2) In the single-point contact range, when the rail cant increases from 1/40 to 1/20, the corresponding rolling radius difference, contact angle parameter, equivalent conicity and equivalent contact angle parameter all increase, which means the self-centring capacity of wheelset is enhanced and the wheel-rail relationship is improved. (3) When the train passes curves, the increase of rail cant from 1/40 to 1/20 can reduce the wheel-rail dynamic interaction and wear. Besides, the wheel-rail contact area may become bigger, which is conductive to reducing contact stress and contact fatigue failures. The results can provide reference for the design of rail cant of heavy haul railway.

Reducing rail side wear on heavy-haul railway curves based on wheel–rail dynamic interaction

2014 ◽  
Vol 52 (sup1) ◽  
pp. 440-454 ◽  
Author(s):  
Wanming Zhai ◽  
Jianmin Gao ◽  
Pengfei Liu ◽  
Kaiyun Wang
Keyword(s):  
Dynamic Interaction ◽  
Heavy Haul ◽  
Heavy Haul Railway

Effects of Track Elasticity on Wheel-Rail Dynamic Performance of Heavy Haul Railway

2015 ◽  
Vol 744-746 ◽  
pp. 1249-1252 ◽  
Author(s):  
Yong Zeng
Keyword(s):  
Lateral Displacement ◽  
Dynamic Performance ◽  
Lateral Force ◽  
Vertical Force ◽  
Heavy Vehicles ◽  
Derailment Coefficient ◽  
Heavy Haul ◽  
Dynamics Models ◽  
Heavy Haul Railway ◽  
The Impact

Two vehicle-track dynamics models on heavy haul railway are established in two conditions of rigid track and elastic track. And the impact of track elasticity on the wheel-rail dynamics performance was analyzed using models. The results show that the critical speed of heavy vehicles and wheel-rail dynamic indexes, such as wheel-rail lateral force and wheel-rail vertical force decreased on elastic track compared with rigid track. However, other dynamic indexes, including derailment coefficient and lateral displacement of wheelsets increased on elastic track. And the wheel-rail wear indexes are some differences on two tracks.

scholarly journals Comparison of stress induced in mandible around an implant-supported overdenture with locator attachment and telescopic crowns – a finite element analysis

2020 ◽  
Author(s):  
Meer Rownaq Ali Abbasi ◽  
Dileep Nag Vinnakota ◽  
Vijaya Sankar V ◽  
Rekhalakshmi Kamatham
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Clinical Performance ◽  
Compressive Load ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Finite Element Program ◽  
Static Contact ◽  
Element Program ◽  
Von Mises

Introduction. One of the principle factors for the success of implant supported/retained overdentures (IOs) is the manner in which the stresses are transferred to the surrounding bone. Hence, the aim of the present study is to compare the stress induced in the mandible around IOs, using two different attachment systems, locator and telescopic. Methods. 3D finite element models were prepared using Pro/ENGINEER or PTC Creo to simulate 4 clinical situations: IOs using two different attachment systems, locator and telescopic, with and without splinting. A vertical compressive load of 35N was directed toward the central fossa in the molar region of each overdenture. Non-linear static contact analysis was carried out to determine the stress distribution in various components of IOs. Then, the models were analyzed by a finite element program ABAQUS, and displayed using Von Mises stress patterns. Results. The contact stress values developed on the implant and attachment components were lower with locator attachment, in both splinted and non-splinted models. On the other hand, the stress distribution to the cortical bone was more with non-splinted/splinted locator attachments (3.73/4.12 Mega Pascals) when compared to the non-splinted/splinted telescopic attachments (2.66/3.7 Mega Pascals). The stresses in all the components of overdenture were greater with the splinted model compared to non-splinted, in both the attachment systems.  Conclusion. The locator attachment might demonstrate superior clinical performance, as the stresses on implant and attachment components were less compared to telescopic. Non-splinted model showed better results in both the attachment types.

scholarly journals Influence of Wheel Profile Wear Coupled with Wheel Diameter Difference on the Dynamic Performance of Subway Vehicles

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
H. X. Li ◽  
A. H. Zhu ◽  
C. C. Ma ◽  
P. W. Sun ◽  
J. W. Yang ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Contact Force ◽  
Ride Comfort ◽  
Dynamic Performance ◽  
Lateral Force ◽  
Dynamics Modeling ◽  
Derailment Coefficient ◽  
Wheel Profile ◽  
Wheel Profile Wear ◽  
Wear Index

In view of the coexistence of wheel profile wear (WPW) and wheel diameter difference (WDD) on an actual subway line, a dynamic analysis method based on coupling between WPW and equivalent in-phase WDD was proposed. Based on the measurements from a subway vehicle in operation on this line, dynamics modeling and calculations were performed for a single carriage of this vehicle. Later, the interaction between the effects of WPW and equivalent in-phase WDD on the vehicle dynamic performance was analyzed, and the dynamic response in the presence of coupled damage was compared between the outer and inner wheels. Furthermore, the difference in the dynamic response caused by different positions of the larger-diameter wheels (i.e., on the inner track or outer track) was analyzed for the case where equivalent in-phase WDD occurred between the front and rear bogies. The results show that when the vehicle ran on a straight line, the coupling between WPW and WDD reduced the vehicle’s stability but improved its ride comfort. When the vehicle traveled on a curved line, it showed reductions in the lateral wheel/rail contact force, derailment coefficient, axle lateral force, and wear index if the outer wheels had a larger diameter. As a result, the deterioration of the vehicle’s dynamic performance due to the increasing degree of WPW slowed down, and its curve negotiation performance improved. Meanwhile, the outer wheels had significantly greater lateral wheel/rail contact force, derailment coefficient, and wear index compared to the inner wheels. When a −1 mm WDD was coupled with the worn wheel profile for 14 × 104 kilometers traveled, the dynamic performance indexes of the vehicle were close to or even exceeded the corresponding safety limits. The findings can provide technical support for subway vehicle maintenance.

scholarly journals ASSESSMENT OF APPLE DAMAGE CAUSED BY A FLEXIBLE END-EFFECTOR

2020 ◽  
pp. 309-317
Author(s):  
LingXin Bu ◽  
ChengKun Chen ◽  
GuangRui Hu ◽  
JianGuo Zhou ◽  
Adilet Sugirbay ◽  
...  
Keyword(s):  
Contact Force ◽  
Mechanical Damage ◽  
Von Mises Stress ◽  
End Effector ◽  
Damage Degree ◽  
Interaction Control ◽  
Fin Ray ◽  
Von Mises ◽  
Non Destructive ◽  
Maximum Contact

In recent years, apple harvesters have become a research hotspot. Interaction control between the robot end-effector and the fruit is crucial to reduce mechanical damage to the fruit and achieve high picking performance. In this article, the damage degree was also quantified using a damage factor based on the damage plasticity model. A flexible three-finger end-effector was designed based on the Fin-Ray effect, and finite element models were established in ABAQUS to simulate the cortex damage during grasping. The results showed that the maximum von Mises stress was 0.159 MPa for the apple skin, 0.082 MPa for the cortex, and 4.178 N for the contact force, respectively. The result of the verification test showed that the maximum contact force was 4.572 N, and the relative error between the simulation and experimental results was 8.62%. Simulation and verification tests showed that the flexible three-finger end-effector achieved non-destructive grasping of apples.

Finite Element Simulation of Wheel-Rail Interaction: Technical Note

2018 ◽  
Vol 10 (3) ◽  
Author(s):  
Shiv Prakash Dubey ◽  
Satish C. Sharma ◽  
Suraj P. Harsha
Keyword(s):  
Finite Element ◽  
Technical Note ◽  
Von Mises Stress ◽  
Solid Model ◽  
Element Analysis ◽  
Element Simulation ◽  
Wheel Profile ◽  
Von Mises ◽  
Critical Sections ◽  
Wheel Material

This paper deals with quasi-static analysis of wheel-rail interaction. The model has been developed for analysing the contact patches behaviour, pressure distribution, von mises stress and strain. A solid model has been developed using SOLIDWORKS on the basis of UIC-60 rail profile and S-1002 wheel profile. Finite element analysis of the solid model has been done using ANSYS software. It has been observed that wheel-rail interaction is nonlinear and exceeded the yield strength of wheel material. The analysis of the worn thread of wheel has enabled the identification of the contact patches and critical sections of the wheel-rail interface.

Normal Contact Response of a Coating Containing an Interlayer

2006 ◽  
Vol 514-516 ◽  
pp. 1576-1582 ◽  
Author(s):  
Xian Cheng Zhang ◽  
Bin Shi Xu ◽  
Hai Dou Wang ◽  
Yi Xiong Wu
Keyword(s):  
Maximum Shear Stress ◽  
Maximum Tensile Stress ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Normal Contact ◽  
Static Contact ◽  
Thin Interlayer ◽  
Von Mises ◽  
Contact Response ◽  
Critical Regions

The purpose of the present paper was to investigate the effect of interlayer on the maximum contact stresses in the critical regions in a hard coating under static contact condition using finite element analysis. Four different elastic moduli and nine different thickness of interlayer were used. Modeling results showed that the interlayer did not reduce the maximum shear stress at the coating/substrate interface, whether it was thick or thin. When the thin interlayer was presented, whether it was soft or hard, the maximum tensile stress on surface and maximum von Mises stress within coating were decreased.

scholarly journals Effects on the Various Aluminum Foam Fenders of a Tripod Offshore Wind Turbine Collision Due to a Ship

2020 ◽  
Vol 54 (1) ◽  
pp. 79-96
Author(s):  
Zhiwei Han ◽  
Xinlei Zhao ◽  
Chun Li ◽  
Qinwei Ding
Keyword(s):  
Finite Element ◽  
Shear Stress ◽  
Dynamic Response ◽  
Contact Force ◽  
Aluminum Foam ◽  
Offshore Wind ◽  
Von Mises Stress ◽  
Offshore Wind Turbine ◽  
Structural Dynamic ◽  
Von Mises

AbstractThe interest in offshore wind energy is growing all over the world. Increasingly, offshore wind turbines (OWTs) are being installed close to shipping lanes, which puts them at risk of potential collisions with ships during their service period. This article aims to investigate the structural dynamic response of OWTs to a ship collision. Considering the structure size of the fender as well as the nonlinear characteristics of the structural materials, a finite element model of a 5,000-ton ship colliding with a 4-MW tripod OWT has been developed using the explicit finite element code LS-DYNA. By observing the collision energy conversion, contact force, fender performance, Von Mises stress on the tripod, shear stress, and dynamic response of a nacelle in differently sized fender collision scenarios, it was observed that when the thickness of the fender surpasses 1.1 m, it can protect the OWT from a collision more effectively than with no fender case. Otherwise, the local contact force is cushioned by aluminum foam materials, whose contact force leads to a whole movement of the bearing tripod. The tripod with the aforementioned 1.1-m fender generates a contact force, Von Mises stress, and a shear stress, as well as the anticollision characteristics of a fender and the dynamic responses of a nacelle in 15 scenarios. Therefore, the structural design of the fender is essential in the safety of a tripod foundation in a collision. This article will provide a better understanding of the collision characteristics of the fender in the future.

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