scholarly journals Load Transfer Efficiency Based on Structural Deflection Assessment of the Precast Floating Track

2020 ◽  
Vol 11 (1) ◽  
pp. 120
Author(s):  
Linh Vu ◽  
Yun Suk Kang

In Korea, a precast floating track with anti-vibration isolators was recently developed to reduce the vibration and noise in urban railway stations, without disrupting train operations. This precast floating slab track is a newly developed structure and differs from existing conventional slab tracks. In this study, a Finite Element Method program (MIDAS CIVIL 2019) was used to analyze the load-carrying ability of structures under the train axle loads. After finishing the design, to understand more precisely about load transfer efficiency of this type of track, an assembly test (two load cases) was conducted with three precast panels (with rail 60 K mounted on) and compared with Finite Element Analysis results. The final results satisfied the test standards in Korea, which confirms that the precast floating track has an acceptable safety factor and structural behavior.

2018 ◽  
Vol 2018 ◽  
pp. 1-14
Author(s):  
Xiaolan Liu ◽  
Xianmin Zhang ◽  
Yadong Wang

The evaluation method of load transfer efficiency using falling weight deflectometer is unworkable in remote mountain areas and transportation difficult region. Therefore, a novation method of load transfer efficiency evaluation is proposed using the index of amplitude ratio. Finite element method is applied to study the influence of dowel bar parameters (diameter, length, spacing, and elastic modulus) and pavement structures parameters (thickness and modulus) on load transfer efficiency, frequency, and the ratio of amplitude. Results of finite element model show that the effects of dowel bar and pavement structure parameters on load transfer efficiency and the ratio of amplitude are similar. The load transfer efficiency, frequency, and the ratio of amplitude enhance with the increase of dowel bar diameter, length, and elastic modulus and the decrease of dowel bar spacing. The subgrade modulus has more significant influence on the load transfer efficiency, frequency, and the ratio of amplitude than other pavement parameters. Polynomial function method is utilized to established load transfer mode between deflection-based load transfer efficiency and the ratio of amplitude. The feasibility and reliability of new method is verified by static and dynamic load test. All results are helpful for the development of highway engineering and airport engineering.


2012 ◽  
Vol 178-181 ◽  
pp. 1152-1155 ◽  
Author(s):  
Luo Ke Li ◽  
Yun Liang Li ◽  
Yi Qiu Tan ◽  
Zhong Jun Xue

In a jointed plain concrete pavements, the dowel bar system are used to provide lateral load transfer across transverse joint. Corrosion of commonly used steel dowel in engineering practice reduces their service life and costs considerable maintenance and repair spending for concrete pavements. The objective of this study focus primarily on the performance of none eroded GFRP dowel on LTE( load transfer efficiency) with the help of a three-dimensional finite-element model. The amount of LTE can be obtained directly from comparing the maximum deflection of the concrete slab and the level tensile stress under the concrete slab. According to the finite element results, the larger-diameter GFRP dowel are found to perform the best in this study.


2014 ◽  
Vol 1030-1032 ◽  
pp. 1108-1115
Author(s):  
Guo Xi Liang ◽  
Zhi Gao Liao ◽  
Bo Li ◽  
Liang Zhou ◽  
Er Hao Su ◽  
...  

Joint load transfer ability is the key part of the analysis of the rigid pavement structure. This paper is focused on the load transfer efficiency at joints of monolithic track-bed under new city tramcar loading. Based on the general finite element analysis software ABAQUS, the relationship between the modulus of virtual materials in virtual material layer method and joint load transfer ability is analyzed. Meanwhile, bending stress and deflection for monolithic track-bed structure on edge loading case are calculated under different thickness of the pavement structure.


Author(s):  
Michael I. Hammons

A rational, three-dimensional (3D) finite element modeling technique was developed to predict the structural response of a jointed concrete airport pavement system. Model features include explicit 3D modeling of the slab continua, load transfer capability at the joint, explicit 3D modeling of the base course continua, load transfer capability across the cracks in the base course, and contact interaction between the slabs and base course. Environmental effects were not explicitly included in the model development. The model was applied to predict the response of an instrumented pavement at the Denver International Airport (DIA) to a test vehicle driven over the instrumented pavement under day and night conditions. The DIA pavement was modeled as a three-layer system with the presence of cracking in the base course as well as a variety of interface conditions between the slabs and base course considered. Complex response patterns caused by environmental factors were observed in the data from DIA, making separation of load-induced and environmentally induced response difficult. The general shape and form of the deflection- and stress-based load transfer efficiency predictions from the finite element models match those observed at DIA. Model predictions of stress-based load transfer efficiencies were generally more accurate than predictions of deflection-based load transfer efficiency. The model developed represents a significant advancement in the state of the art and features innovations that are compatible with the FAA’s advanced pavement design model requirements.


2014 ◽  
Vol 18 (2) ◽  
pp. 616-624 ◽  
Author(s):  
Wonseok Chung ◽  
Kusung Kwon ◽  
Seung Yup Jang

2016 ◽  
Vol 61 (2) ◽  
pp. 843-846 ◽  
Author(s):  
J. Żmudzki ◽  
P. Malara ◽  
G. Chladek

Abstract Implant and a tooth supported dentures are avoided by dentists because of uneven distribution of occlusal loads between a stiffer implant and a more pliable tooth. The hypothesis was that a 3-point all-ceramic bridge supported on a natural second premolar tooth and a two-pieces typical implant bears safely mastication loads. The finite element analysis showed that the implant splinted by all-ceramic zirconium bridge with the second premolar was safe under lateral mastication load, but there was found an overload at wide zone of bone tissue around the implant under the load of 800 N. The patients can safely masticate, but comminution of hard food should be avoided and they should be instructed that after such an indiscretion they need to contact a dental professional, because, in spite of integrity of the prosthesis, the bone tissue around the implant may fail and there is a hazard of intrusion of the tooth.


2021 ◽  
Vol 71 (1) ◽  
pp. 58-64
Author(s):  
Raviduth Ramful

Abstract Full-culm bamboo has been used for millennia in construction. Specific connections are normally required to suit its unique morphology and nonuniform structure. Presently, the use of full-culm bamboo is limited in the construction industry as a result of a lack of information and test standards about the use and evaluation of full-culm connections. This study aims to further explore this area by investigating the failure modes in bamboo bolt connections in uniaxial tension by considering fiber direction in finite element analysis. Three types of bolt configurations of varying permutations, namely, single, dual, and orthogonal, were investigated. An orthotropic material was used as a constitutive model in finite element formulation to capture the inhomogeneity prevailing in bamboo culm. From the strain-field analysis of a hollow-inhomogeneous model representing bamboo, shear-out failure was dominant, as a localized area equivalent to the bolt diameter was affected due to high material orthotropy with high axial strength but weak radial and tangential strength. Bearing failure is assumed to precede shear-out failure at the bolt–bamboo contact interface, as the embedding strength was affected by localized strain concentration. The strain distribution in various bolt arrangements was found to vary between bolted connections of inhomogeneous-hollow geometry of bamboo and the ones of inhomogeneous-solid geometry representing timber. The observation in this study highlights the need for alternative design criteria to specifically assess the damage mechanism in bamboo connections.


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