FE Model Of A Cord-Rubber Railway Brake Tube Subjected To Extreme Operational Loads On A Reverse Curve Test Track

2021 ◽  
Author(s):  
Gyula Szabo ◽  
Karoly Varadi
Keyword(s):  
Internal Pressure ◽  
Kinematic Model ◽  
Equivalent Strain ◽  
Railway Vehicle ◽  
Fe Model ◽  
Lower Strain ◽  
Curve Track ◽  
Strain Stress ◽  
Vehicle Components ◽  
Point Distance

In certain cases, rolling stocks and railway vehicle components, i.e. brake tubes need to operate under extreme conditions such as at sub-zero temperature (e.g. -40°C) and on a reverse curve track, when displacements of the suspension points of the tubes cause large deformations in tubes. In this paper, displacements of the suspension points of the tubes are determined by a kinematic model validated by a draw and buffing gear test [1]. Afterwards, FE simulation has been carried out at minimum and maximum suspension point distance based on these displacements for the investigation of stress, strain states and possible failure considering the case of internal pressure and no internal pressure. Equivalent strain, stress and Tsai-Hill failure indices are much below the criterial values, so failure is not probable. The straight section between the curves of opposite curvatures reduces deformation in tubes in the critical positions leading to lower strain, stress and failure index values.

On the Planning and Construction of Railway Curved Track

2021 ◽  
Vol 13 (2) ◽  
Author(s):  
Sono Bhardawaj ◽  
Rakesh Chandmal Sharma ◽  
Sunil Kumar Sharma ◽  
Neeraj Sharma
Keyword(s):  
High Speed ◽  
Time Derivative ◽  
Railway Track ◽  
Lateral Acceleration ◽  
Transition Curve ◽  
Railway Vehicle ◽  
Geometric Conditions ◽  
Curve Track ◽  
Curved Track ◽  
Transition Curves

Increasing demand for railway vehicle speed has pushed the railway track designers to develop high-quality track. An important measure of track quality is the character of the transition curve track connecting different intersecting straight tracks. A good transition curve track must be able to negotiate the intermittent stresses and dynamic effects caused by changes in lateral acceleration at high speed. This paper presents the constructional methods for planning transition curves considering the dynamics of movement. These methods consider the non-compensated lateral acceleration, deviation in lateral acceleration and its higher time derivatives. This paper discusses the laying methods of circular, vertical and transition curves. Key aspects in laying a curved track e.g. widening of gauge on curves are discussed in this paper. This paper also suggests a transition curve which is effective not only from a dynamic point of view considering lateral acceleration and its higher time derivative but also consider the geometric conditions along with the required deflection angle.

Warm forming process for an AA5754 train window panel

2021 ◽  
pp. 1-32
Author(s):  
Antonio Piccininni ◽  
Andrea Lo Franco ◽  
Gianfranco Palumbo
Keyword(s):  
Material Characterization ◽  
Room Temperature ◽  
Warm Forming ◽  
Railway Vehicle ◽  
Fe Model ◽  
Forming Process ◽  
Vehicle Component ◽  
Mechanical Approach ◽  
Thermal Simulations ◽  
Critical Regions

Abstract A warm forming process is designed for AA5754 to overcome low room temperature formability. The solution includes increased working temperature and is demonstrated with a railway vehicle component. A Finite Element (FE) based methodology was adopted to design the process taking into account also the starting condition of the alloy. In fact, the component's dent resistance can be enhanced if the yield point is increased accordingly: the stamping process was thus designed considering the blank in both the H111 (annealed and slightly hardened) and H32 (strain-hardened and stabilized) conditions that were preliminarily characterized. Tensile and formability tests were carried out at different temperature and strain rate levels, thus providing the data to be implemented within the FE model (Abaqus/CAE): the stamping was at first simulated at room temperature to evaluate the blank critical regions. Subsequently, the warm forming process was designed by means of an uncoupled thermo-mechanical approach. Thermal simulations were run to properly design the heating strategy and achieve an optimal temperature distribution over the blank deformation zone (according to the results of the material characterization). Such a distribution was then imported as a boundary condition into the mechanical step (Abaqus/Explicit) to determine the optimal process parameters and obtain a sound component (strain severity was monitored implementing an FLD-based damage criterion). The simulation model was validated experimentally with stamping trials to fabricate a sound component using the optimized heating strategy and punch stroke profile.

Effect of Expansion Ratio and Wall Thickness on Large-Diameter Solid Expandable Tubular after Expansion

2021 ◽  
Author(s):  
Changshuai Shi ◽  
Kailin Chen ◽  
Xiaohua Zhu ◽  
Feilong Cheng ◽  
Yuekui Qi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Internal Pressure ◽  
Wall Thickness ◽  
Performance Test ◽  
Large Diameter ◽  
Expansion Ratio ◽  
Fe Model ◽  
Laboratory Test Results ◽  
Low Efficiency ◽  
Pressure Resistance

Abstract The large-diameter solid expandable tubular with a smaller wall thickness faces the risk of internal pressure burst and external squeeze collapse in repairing damaged casing well. The internal pressure and external squeezing resistance calculation of the tubes using the analytical method require many expansion experiments and post-expansion tensile experiments, resulting in high costs and low efficiency. This paper gives a set of laboratory expansion and post-expansion performance test, which is based on the laboratory experiment and mechanical properties of material expansion. Two materials are studied: 316L and 20G. Then it analyses the error and causes of the error in the traditional analytical algorithm. Besides, it establishes an accurate finite element (FE) model to study the quantitative influence of expansion ratio and wall thickness on the burst strengths and collapse strengths of the tube. The results show that the toughness and hardening ratio of 316L is better than 20G at the same expansion ratio. The numerical simulation results of the model can effectively simulate the expansion process and the mechanical properties of SET in good agreement with the laboratory test results. The expansion ratio and wall thickness affect the mechanical properties after expansion. Thus the quantitative laws of the expansion driving force, internal pressure resistance, and external squeezing resistance under different variables are summarized. To ensure the integrity of the reinforced wellbore, the expansion ratio should not exceed 12.7%. In the current study lays a theoretical basis and technical support for optimizing SET and preventing downhole accidents.

A Comprehensive Study on Burst Pressure Performance of Aluminum Liner for Hydrogen Storage Vessels

2021 ◽  
Vol 143 (4) ◽  
Author(s):  
Serkan Kangal ◽  
A. Harun Sayı ◽  
Ozan Ayakdaş ◽  
Osman Kartav ◽  
Levent Aydın ◽  
...  
Keyword(s):  
Internal Pressure ◽  
Axial Strain ◽  
Cylindrical Part ◽  
Pressure Vessels ◽  
Fe Analysis ◽  
Burst Pressure ◽  
Experimental Investigations ◽  
Fe Model ◽  
Stress Criterion ◽  
Analytical Approaches

Abstract This paper presents a comparative study on the burst pressure performance of aluminum (Al) liner for type-III composite overwrapped pressure vessels (COPVs). In the analysis, the vessels were loaded with increasing internal pressure up to the burst pressure level. In the analytical part of the study, the burst pressure of the cylindrical part was predicted based on the modified von Mises, Tresca, and average shear stress criterion (ASSC). In the numerical analysis, a finite element (FE) model was established in order to predict the behavior of the vessel as a function of increasing internal pressure and determine the final burst. The Al pressure vessels made of Al-6061-T6 alloy with a capacity of 5 L were designed. The manufacturing of the metallic vessels was purchased from a metal forming company. The experimental study was conducted by pressurizing the Al vessels until the burst failure occurred. The radial and axial strain behaviors were monitored at various locations on the vessels during loading. The results obtained through analytical, numerical, and experimental work were compared. The average experimental burst pressure of the vessels was found to be 279 bar. The experimental strain data were compared with the results of the FE analysis. The results indicated that the FE analysis and ASSC-based elastoplastic analytical approaches yielded the best predictions which are within 2.2% of the experimental burst failure values. It was also found that the elastic analysis underestimated the burst failure results; however, it was effective for determining the critical regions over the vessel structure. The strain behavior of the vessels obtained through experimental investigations was well correlated with those predicted through FE analysis.

scholarly journals Improved backward fatigue statistical inference to the high-speed railway vehicle components

2019 ◽  
Vol 22 ◽  
pp. 211-218
Author(s):  
S.C. Wu ◽  
C.H. Li ◽  
G.Z. Kang ◽  
L.Y. Xie ◽  
W.H. Zhang
Keyword(s):  
Statistical Inference ◽  
High Speed ◽  
Railway Vehicle ◽  
High Speed Railway ◽  
Vehicle Components

Effect of curving speed and mass of railway vehicle to the contact characteristic on curve track

2011 ◽  
Vol 6 (3/4) ◽  
pp. 250 ◽  
Author(s):  
I. Made Parwata ◽  
Bagus Budiwantoro ◽  
Satryo S. Brodjonegoro ◽  
I.G.N. Wiratmaja Puja
Keyword(s):  
Railway Vehicle ◽  
Contact Characteristic ◽  
Curve Track

Finite Element Modelling of Static and Fatigue Failure of Composite Repair System in Offshore Pipe Risers

2014 ◽  
Vol 875-877 ◽  
pp. 1063-1068 ◽  
Author(s):  
Park Hinn Chan ◽  
Kim Yeow Tshai ◽  
Michael Johnson ◽  
Hui Leng Choo
Keyword(s):  
Finite Element ◽  
Internal Pressure ◽  
Low Cycle Fatigue ◽  
Failure Mechanisms ◽  
Repair System ◽  
Fe Model ◽  
Composite Surface ◽  
Composite Repair ◽  
Bending Load ◽  
Static Conditions

The static and cyclic failure mechanisms of offshore pipe riser repaired with a designated laminate orientation of carbon/epoxy (C/E) system were studied. The finite element (FE) model takes into account failure mechanisms of the composite sleeve inter-layer delamination, debonding at the steel riser-composite surface interface, and the maximum permissible strain of the repaired riser. Design conditions of the combined static loads (coupled internal pressure, longitudinal tensile and transverse bending) were determined through a limit state analysis [1,2]. The limiting static bending load that causes catastrophic failure under a coupled internal pressure and tensile loadings was determined through Virtual Crack Closure Technique (VCCT). The effects of cyclic bending, mimicking the typical scenarios experienced in pipe riser exposed to dynamic subsea environment, were evaluated and compared against the static conditions. The low cycle fatigue of the composite repair system (CRS) is simulated using a direct cyclic analysis within a general purpose FE program, where the onset and fatigue delamination/disbonding growth are characterized through the Paris Law.

Research on Hot State of Mould Copper Plate with High Casting Speed

2011 ◽  
Vol 337 ◽  
pp. 214-218
Author(s):  
Li Gen Sun ◽  
Hui Rong Li ◽  
Jia Quan Zhang
Keyword(s):  
Casting Speed ◽  
Distribution Curve ◽  
Thermal State ◽  
Process Analysis ◽  
Great Influence ◽  
Equivalent Strain ◽  
Copper Plate ◽  
Steel Shell ◽  
High Casting Speed ◽  
Strain Stress

High casting speed has a great influence to thermal state and strain/stress field of the mould copper plate. The coupled visco-elasto-plastic FEM models have been presented for thermal process analysis of steel shell and the mould copper plates. It is shown that, when the casting speed is increasing, the turning point of the temperature distribution curve is getting further to the meniscus; and the increasing casting speed has no influence to the equivalent strain distribution along the thickness direction of the mould.

FEM-Based Simulation and Gripper Jaw Trajectory Fitting of Stretch-Bending Process for a Bending Beam of Railway Vehicles

2013 ◽  
Vol 372 ◽  
pp. 661-665
Author(s):  
Sheng Man Wang ◽  
Xin Hua Yang ◽  
Xing Lu
Keyword(s):  
Control Method ◽  
Die Design ◽  
Railway Vehicle ◽  
Fe Model ◽  
The Finite Element Method ◽  
Forming Process ◽  
Stretch Bending ◽  
Bending Process ◽  
Design Requirements ◽  
Displacement Control Method

The bending beam of railway vehicle is made of thin stainless steel, with large sizes and unsymmetrical section, and prone to defects during stretch-bending forming process, such as wrinkling, cross-section distortion and so on. A reasonable trajectory of gripper jaws could make for mitigating the mentioned defects. The Finite Element Method was employed to fit the trajectory as well as simulate the forming process. The FE model was built by using the commercial FE software Hypermesh and ABAQUS/CAE. The analysis was carried out based on dynamic explicit and displacement control method. On this basis, the actual stretch bending process was developed according to the fitted trajectory and simulated process. The actual production process indicates that the formed beam can meet the design requirements, and the method is feasible and economical, as well as can contribute to a better understanding of stretch bending process and die design.

Experimentally tested computer modeling of stress fractures in rats

2011 ◽  
Vol 110 (4) ◽  
pp. 909-916 ◽  
Author(s):  
Michal Stern-Perry ◽  
Amit Gefen ◽  
Nogah Shabshin ◽  
Yoram Epstein
Keyword(s):  
Three Dimensional ◽  
Muscle Stiffness ◽  
Male Rats ◽  
Cyclic Loads ◽  
Fe Model ◽  
Stress Distributions ◽  
Fe Modeling ◽  
Sprague Dawley ◽  
Modeling Methodology ◽  
Strain Stress

The objective of this study was to develop a finite-element (FE) modeling methodology for studying the etiology of a stress fracture (SF). Several variants of three-dimensional FE models of a rat hindlimb, which differed in length or stiffness of tissues, enabling the analyses of mechanical strains and stress in the tibia, were created. We compared the occurrence of SFs in an animal model to validate locations of peak strains/stresses in the FE models. Four Sprague-Dawley male rats, age ∼7 wk, were subjected to mechanical cyclic loads of 1.2 Hz and ∼6 N, which were delivered to their hindlimb for 30 min, 3 times/wk, up to 12 wk, by using a specially designed apparatus. The results showed that 1) FE modeling predicted the maximal strains/stresses (∼220,0 με and ∼29 MPa, respectively) between the mid- and proximal thirds of the tibia; 2) in a longer shin, greater and more inhomogeneous tensile strains/stresses were evident, at the same location; 3) anatomical variants in shin length influenced the strain/stress distributions to a greater extent with respect to changes in mechanical properties of tissues; and 4) bone stiffness was more dominant than muscle stiffness in affecting the strain/stress distributions. In the animal study, 35,000 loading cycles were associated with the formation of a SF. The location of the identified SF in the rat limb verified the FE model. We find the suggested model a valuable tool in studying various aspects of SFs.

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