scholarly journals Optimization of ER8 and 42CrMo4 Steel Rail Wheel for Road–Rail Vehicles

2020 ◽  
Vol 10 (14) ◽  
pp. 4717
Author(s):  
Filip Lisowski ◽  
Edward Lisowski
Keyword(s):  
Geometry Optimization ◽  
High Strength ◽  
Railway Track ◽  
Hydraulic Motor ◽  
Steel Rail ◽  
Element Analysis ◽  
Track Maintenance ◽  
Rail Vehicles ◽  
First Order Method ◽  
Failure Site

Railway track maintenance services aim to shorten the time of removing failures on the railways. One of the most important element that shorten the repair time is the quick access to the failure site with an appropriate equipment. The use of road-rail vehicles is becoming increasingly important in this field. In this type of constructions, it is possible to use proven road vehicles such as self-propelled machines or trucks running on wheels with tires. Equipping these vehicles with a parallel rail drive system allows for quick access to the failure site using both roads and railways. Steel rail wheels of road-rail vehicles are designed for specific applications. Since the total weight of vehicle is a crucial parameter for roadworthiness, the effort is made to minimize the mass of rail wheels. The wheel under consideration is mounted directly on the hydraulic motor. This method of assembly is structurally convenient, as no shafts or intermediate couplings are required. On the other hand, it results in strict requirements for the wheel geometry and can cause significant stress concentration. Therefore, the problem of wheel geometry optimization is discussed. Consideration is given to the use of ER8 steel for railway application and 42CrMo4 high-strength steel. Finite element analysis within Ansys software and various optimization tools and methods, such as random tool, subproblem approximation method and first-order method are applied. The obtained results allow to minimize the rail wheel mass with respect to the used material. Moreover, computational demands and methods leading to the best results are compared.

scholarly journals A discussion for the reduction in the length of a prestressed concrete railway tie in time

2021 ◽  
Author(s):  
Niyazi Özgür Bezgin
Keyword(s):  
Prestressed Concrete ◽  
High Strength ◽  
Railway Track ◽  
Structural Elements ◽  
Track Maintenance ◽  
Concrete Shrinkage ◽  
Prestressing Force ◽  
Steel Wires ◽  
Practical Evaluation ◽  
And Performance

Increasing train speeds, contemporary requirements for reduced track maintenance costs and extended track service lives required the development and use of reinforced concrete and prestressed concrete ties. Railway engineers began to use concrete for their bi-block and monoblock railway ties heavily, following the development of an understanding for design and performance of concrete structures, production of high strength steel wires and preferable economy of prefabricated mass production for reinforced and prestressed concrete structural elements following the first half of 20th Century. Structural elements of a railway track such as reinforced or prestressed concrete ties have strict production tolerances that are not common for ordinary structural elements. Production of concrete railway ties takes place under strict dimensional control that ensures a nominal design gauge width for the railway track. Design specifications for prestressed monoblock ties frequently specify the gauge width and the shoulder width to be within 1 mm of the design width. However, prestressed concrete ties experience shortenings in length due to transfer of the prestressing force known as instant elastic shortening and shortenings due to concrete shrinkage and concrete creep in time that also relate to ambient relavite humidity. The author conducted numerous studies on the matter, showed by calculation, and observed experimentally that if unaccounted for, such shortenings can surpass the allowed tolerances in time and result in the rejection of the produced tie for use in the railway track. This paper refers to previous studies by the author that brought international attention on the issue and presents a thorough and a practical evaluation of time related changes in tie lengths for a particular design for prestressed concrete monoblock ties under varying ambient humidity conditions.

scholarly journals Failure Analysis on a Collapsed Flat Cover of an Adjustable Ballast Tank Used in Deep-Sea Submersibles

2019 ◽  
Vol 9 (23) ◽  
pp. 5258
Author(s):  
Fang Wang ◽  
Mian Wu ◽  
Genqi Tian ◽  
Zhe Jiang ◽  
Shun Zhang ◽  
...  
Keyword(s):  
Deep Sea ◽  
Material Selection ◽  
High Strength ◽  
External Pressure ◽  
Element Analysis ◽  
Ballast Tank ◽  
Material Inhomogeneity ◽  
Comprehensive Properties ◽  
Ultimate Cause ◽  
Flat Cover

A flat cover of an adjustable ballast tank made of high-strength maraging steel used in deep-sea submersibles collapsed during the loading process of external pressure in the high-pressure chamber. The pressure was high, which was the trigger of the collapse, but still considerably below the design limit of the adjustable ballast tank. The failure may have been caused by material properties that may be defective, the possible stress concentration resulting from design/processing, or inappropriate installation method. The present paper focuses on the visual inspections of the material inhomogeneity, ultimate cause of the collapse of the flat cover in pressure testing, and finite element analysis. Special attention is paid to the toughness characteristics of the material. The present study demonstrates the importance of material selection for engineering components based on the comprehensive properties of the materials.

scholarly journals A Taxonomy of Railway Track Maintenance Planning and Scheduling: A Review and Research Trends

2021 ◽  
pp. 107827
Author(s):  
Mahdieh Sedghi ◽  
Osmo Kauppila ◽  
Bjarne Bergquist ◽  
Erik Vanhatalo ◽  
Murat Kulahci
Keyword(s):  
Research Trends ◽  
Railway Track ◽  
Maintenance Planning ◽  
Planning And Scheduling ◽  
Track Maintenance

Accelerated testing of super lightweight UHPC waffle deck under heavy vehicle simulator

2021 ◽  
Vol 16 (2-3) ◽  
pp. 61-74
Author(s):  
Sahar Ghasemi ◽  
Amir Mirmiran ◽  
Yulin Xiao ◽  
Kevin Mackie
Keyword(s):  
High Performance ◽  
Failure Modes ◽  
High Performance Concrete ◽  
High Strength ◽  
Heavy Vehicle ◽  
Wheel Load ◽  
Element Analysis ◽  
Vehicle Simulator ◽  
Pavement Testing ◽  
Heavy Vehicle Simulator

A super lightweight deck can enhance load rating and functionality of a bridge, especially those identified as structurally deficient. This study was aimed to develop and experimentally validate a novel bridge deck as an ultra-lightweight low-profile waffle slab of ultra-high-performance concrete (UHPC) with either carbon fiber reinforced polymer (CFRP) or high strength steel (HSS) reinforcement. The proposed system lends itself to accelerated bridge construction, rapid deck replacement in bridges with load restrictions, and bridge widening applications without the need to replace girders. Performance and failure modes of the proposed deck were initially assessed through extensive lab experiments and finite element analysis, which together confirmed that the proposed deck panel meets the AASHTO LRFD requirements. The proposed deck system is not susceptible to punching shear of its thin slab and fails in a rather ductile manner. To evaluate its long-term performance, the system was further tested under the dynamic impact of wheel load at the Accelerated Pavement Testing (APT) facility of the Florida Department of Transportation using a Heavy Vehicle Simulator (HVS).

scholarly journals Multi-Stage Cold Forging Process for Manufacturing a High-Strength One-Body Input Shaft

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 532
Author(s):  
A Jo ◽  
Myeong Jeong ◽  
Sang Lee ◽  
Young Moon ◽  
Sun Hwang
Keyword(s):  
High Strength ◽  
Microstructural Characterization ◽  
Fatigue Tests ◽  
Machining Process ◽  
Cold Forging ◽  
Element Analysis ◽  
Forging Process ◽  
Input Shaft ◽  
Multi Stage ◽  
The One

A multi-stage cold forging process was developed and complemented with finite element analysis (FEA) to manufacture a high-strength one-body input shaft with a long length body and no separate parts. FEA showed that the one-body input shaft was manufactured without any defects or fractures. Experiments, such as tensile, hardness, torsion, and fatigue tests, and microstructural characterization, were performed to compare the properties of the input shaft produced by the proposed method with those produced using the machining process. The ultimate tensile strength showed a 50% increase and the torque showed a 100 Nm increase, confirming that the input shaft manufactured using the proposed process is superior to that processed using the machining process. Thus, this study provides a proof-of-concept for the design and development of a multi-stage cold forging process to manufacture a one-body input shaft with improved mechanical properties and material recovery rate.

Benefits of Using Diamond Dies for Cold Alternate Drawing of Magnesium Alloys

2016 ◽  
Vol 716 ◽  
pp. 13-21 ◽  
Author(s):  
Vladimir Stefanov Hristov ◽  
Kazunari Yoshida
Keyword(s):  
Magnesium Alloy ◽  
Weight Ratio ◽  
High Strength ◽  
Wire Drawing ◽  
High Ductility ◽  
Element Analysis ◽  
The Wire ◽  
Shearing Strain ◽  
Drawing Method

In recent years, due to its low density and high strength/weight ratio, magnesium alloy wires has been considered for application in many fields, such as welding, electronics, medical field (for production of stents). But for those purposes, we need to acquire wires with high strength and ductility. For that we purpose we proposed alternate drawing method, which is supposed to highly decrease the shearing strain near the surface of the wire after drawing, by changing the direction of the wire drawing with each pass and thus acquiring high ductility wires.We have done research on the cold alternate drawing of magnesium alloy wires, by conducting wire drawing of several magnesium wires and testing their strength, hardness, structure, surface and also finite element analysis, we have proven the increase of ductility at the expense of some strength.In this research we are looking to further improve the quality of the drawn wires by examining the benefits of using diamond dies over tungsten carbine dies. Using the alternate drawing method reduces the strength of the drawn wires and thus lowering their drawing limit. By using diamond dies we are aiming to decrease the drawing stress and further increase the drawing limit of the alternate drawn wires and also improve the quality of the finishing surface of the wires. With this in mind we are aiming to produce a good quality wire with low diameter, high ductility, high strength and fine wire surface.

Study on the Local Buckling Behavior of Steel Equal Angle Members under Axial Compression with the Steel Strength Variation

2011 ◽  
Vol 374-377 ◽  
pp. 2430-2436
Author(s):  
Gang Shi ◽  
Zhao Liu ◽  
Yong Zhang ◽  
Yong Jiu Shi ◽  
Yuan Qing Wang
Keyword(s):  
Finite Element ◽  
Axial Compression ◽  
High Strength Steel ◽  
Local Buckling ◽  
Steel Structures ◽  
High Strength ◽  
Element Analysis ◽  
Equal Angle ◽  
Buckling Behavior ◽  
Steel Strength

High strength steel sections have been increasingly used in buildings and bridges, and steel angles have also been widely used in many steel structures, especially in transmission towers and long span trusses. However, high strength steel exhibits mechanical properties that are quite different from ordinary strength steel, and hence, the local buckling behavior of steel equal angle members under axial compression varies with the steel strength. However, there is a lack of research on the relationship of the local buckling behavior of steel equal angle members under axial compression with the steel strength. A finite element model is developed in this paper to analyze the local buckling behavior of steel equal angle members under axial compression, and study its relationship with the steel strength and the width-to-thickness ratio of the angle leg. The finite element analysis (FEA) results are compared with the corresponding design method in the American code AISC 360-05, which provides a reference for the related design.

Analysis Study on Axial Force in Bolted Connection under Fatigue Load

2016 ◽  
Vol 858 ◽  
pp. 57-60
Author(s):  
Kwan Sik Park ◽  
Jae Hyuk So ◽  
Keun Yeong Oh ◽  
Kang Min Lee
Keyword(s):  
Steel Structure ◽  
High Strength ◽  
Clamping Force ◽  
Fatigue Load ◽  
Element Analysis ◽  
Bolted Connection ◽  
The Finite Element Analysis ◽  
Strength And Deformation ◽  
Main Factor ◽  
Ansys Workbench

High-strength bolted connection is widely used for steel structure construction. Because high-strength bolted connection has simple constructability and structural qualification. Especially friction type with high-strength bolted connection has high stiffness and fatigue strength. At this time, initial clamping force is one of main factor to affect the strength and deformation behavior of connection. Therefore, the objective of this study is to investigate reduction of initial clamping force in high-strength bolted connection under fatigue load. And the parameter of this study is the size of the bolt and 3 types of initial clamping force. The analysis is used the finite element analysis program ANSYS Workbench.

Enhancement of Bone Implants by Substituting Nitinol for Titanium (Ti-6Al-4V): A Modeling Comparison

2014 ◽  
Author(s):  
Narges Shayesteh Moghaddam ◽  
Mohammad Elahinia ◽  
Michael Miller ◽  
David Dean
Keyword(s):  
Tumor Resection ◽  
Stress Shielding ◽  
High Strength ◽  
Standard Of Care ◽  
Mandibular Reconstruction ◽  
Bone Plate ◽  
Segmental Defect ◽  
Stress Strain ◽  
Element Analysis ◽  
Grade 5

Mandibular segmental defect reconstruction is most often necessitated by tumor resection, trauma, infection, or osteoradionecrosis. The standard of care treatment for mandibular segmental defect repair involves using metallic plates to immobilize fibula grafts, which replace the resected portion of mandible. Surgical grade 5 titanium (Ti-6Al-4V) is commonly used to fabricate the fixture plate due to its low density, high strength, and high biocompatibility. One of the potential problems with mandibular reconstruction is stress shielding caused by a stiffness mismatch between the Titanium fixation plate and the remaining mandible bone and the bone grafts. A highly stiff fixture carries a large portion of the load (e.g., muscle loading and bite force), therefore the surrounding mandible would undergo reduced stress. As a result the area receiving less strain would remodel and may undergo significant resorption. This process may continue until the implant fails. To avoid stress shielding it is ideal to use fixtures with stiffness similar to that of the surrounding bone. Although Ti-6Al-4V has a lower stiffness (110 GPa) than other common materials (e.g., stainless steel, tantalum), it is still much stiffer than the cancellous (1.5–4.5 GPa) and cortical portions of the mandible (17.6–31.2 GPa). As a solution, we offer a nitinol in order to reduce stiffness of the fixation hardware to the level of mandible. To this end, we performed a finite element analysis to look at strain distribution in a human mandible in three different cases: I) healthy mandible, II) resected mandible treated with a Ti-6Al-4V bone plate, III) resected mandible treated with a nitinol bone plate. In order to predict the implant’s success, it is useful to simulate the stress-strain trajectories through the treated mandible. This work covers a modeling approach to confirm superiority of nitinol for mandibular reconstruction. Our results show that the stress-strain trajectories of the mandibular reconstruction using nitinol fixation is closer to normal than if grade 5 surgical titanium fixation is used.

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