scholarly journals Experimental and Numerical Analyses of the Failure of Prestressed Concrete Railway Sleepers

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1704 ◽  
Author(s):  
Ramon Silva ◽  
Welington V. Silva ◽  
Jonas Yamashita de Farias ◽  
Marcos Aires A. Santos ◽  
Leonardo O. Neiva

This paper carries out the assessment of load-carrying capacity of prestressed concrete sleepers, in accordance with Brazilian Standard (ABNT NBR 11709) and AREMA Standard. In a lot of railways around the world, many prestressed concrete sleepers have failed due to Rail Seat Abrasion (RSA) and corrosion. RSA is the wear degradation underneath the rail on the surface of prestressed concrete sleepers. In this paper, a numerical study was carried out to evaluate the load-carrying capacity of the prestressed concrete sleepers, using ABAQUS software. The nonlinear using Concrete Damage Plasticity model was validated by 18 experimental results, in accordance to standards. Using the validated model, the influence of different wear depth RSA, combined with corrosion of the prestressed wires, is investigated.

Author(s):  
Xiandong Liao ◽  
Xiang Hu

The seismic performance of the internal connection of precast prestressed concrete frame was studied systematically, based on the experiment of full-scale model under low cyclic reversed loading. This study was mainly focused on failure pattern, load-carrying capacity, skeleton curves, and hysteresis curves. Furthermore, a nonlinear finite element analysis using Abaqus was carried out to study the characteristics of the internal connection of precast prestressed concrete frame. Results revealed that the damage was concentrated mainly on beam end owing to flexural action, while steel bars in the columns and stirrups in the core region remained elastic until failure occurred. The calculated value of the load-carrying capacity of the internal connection was similar to the experimental one. Present study can be referenced for the application of precast prestressed concrete frame in high seismic zones.


Author(s):  
Sanjay Sharma ◽  
Aniket Sharma ◽  
Gourav Jamwal ◽  
Rajeev Kumar Awasthi

The present comparative numerical study is between V-shape protruded, dimple textured, and untextured bearing. The performance parameters in terms of the load-carrying capacity and coefficient of friction are computed by solving governing Reynold’s equation of the lubricant fluid flow. The governing equation is solved by the finite element method by assuming that the fluid is Newtonian and isoviscous in nature. The effect of eccentricity ratios, texture distribution, texture heights, and texture depths are considered for the analysis in both textured bearings. From simulated results, the load-carrying capacity and coefficient of friction is found to be maximum for protruded textured bearing in full textured region and first half-textured region respectively as compared to untextured bearings. Finally, optimal operating and geometrical parameters of textured bearing is obtained by computing performance enhancement ratio, which is the ratio of the load-carrying capacity to the coefficient of friction. The maximum value of the performance enhancement ratio is found for protruded and dimple textured bearing in full texturing and second half-region corresponding to the eccentricity ratio of 0.8 and 0.6 respectively at texture height and depth of 0.4.


1994 ◽  
pp. 83-92
Author(s):  
Yoshimi Sonoda ◽  
Nobutaka Ishikawa ◽  
Keiichiro Sonoda ◽  
Toshiaki Ohta

Author(s):  
Fredrik Sahlin ◽  
Sergei B. Glavatskih ◽  
Torbjo¨rn Almqvist ◽  
Roland Larsson

Results of a numerical study of the influence of micro-patterned surfaces in hydrodynamic lubrication of two parallel walls are reported. Two types of parameterized grooves with the same order of depth as the film thickness are used on one stationary wall. The other wall is smooth and is sliding with a specified tangential velocity. Isothermal incompressible two dimensional full film fluid flow mechanics is solved using a Computational Fluid Dynamics method. It is shown that, by introducing a micro-pattern on one of two parallel walls, a net pressure rise in the fluid domain is achieved. This produces a load carrying capacity on the walls which is mainly contributed by fluid inertia. The load carrying capacity increases with Reynolds number. The load carrying capacity is reported to increase with groove width and depth. However, at a certain depth a vortex appears in the groove and near this value the maximum load carrying capacity is achieved. It is shown that the friction force decreases with deeper and wider grooves. Among all geometries studied, optimum geometry shapes in terms of hydrodynamic performance are reported.


Author(s):  
V. Bogaert

<p>The Floraliahall in Ghent was built during 1912-1913 as part of a series of large infrastructure works for the world exposition of 1913. The main structure of the hall consists of 18 portal frames having 3 spans of 10.16, 40.18 and 10.16 m. The upper part of the structure is highly slender. Adversely to the customary concepts of 100 years ago, the lighter frames at 7.45 m distance, are hinged twice at the springs, whereas the more heavy frames, at 15 m distance, are completely clamped at their base. In addition, measurements show that crosssections of compressed parts have larger area than the tensile parts. From the structural point of view, these frames sometimes have an unexpected composition. The aim was to determine whether this structure can comply with contemporary requirements and codes. From measurements and simulations follows that in limited areas high stresses appear, unacceptable even in serviceability state. This may be partly due to modifications of the roof that were made inappropriately, from the uncertainty to assess certain details with the model and from ineffective analysis at the time of construction.</p>


2016 ◽  
Vol 78 (5-4) ◽  
Author(s):  
Nurain Rosdi ◽  
Mohd Hanafie Yasin ◽  
Mohd Hazim Mohd Azam ◽  
Rohana Hassan

Over recent years, half-lap connection is widely used all over the world to provide longer structural member due to limited size of sawn timber in construction industries. Timber connected in joints may reduce overall mechanical properties of the structure. This paper present finding on a series of connection of half lap bolted joint member from Keruing (SG5) and Sesendok (SG7) timber species. The half-lap connection were subjected to tensile test and reinforced with GFRP sheet that were conducted until failure to determine their tensile behavior. The results showed that the GFRP help to increase the load carrying capacity of all the timber specimens especially timber species that lies in a weak strength group for almost 30 % by strength.


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