scholarly journals “Mechanistic Analysis of Rigid Pavement for Wheel Load Stresses By Finite Element Method Considering Different Sub-Grade with Different Percentage of Metal Fibre”

2021 ◽  
Vol 1 (2) ◽  
pp. 1-9
Author(s):  
Mohd. Imran Khan ◽  
◽  
Dr. Ahmad Ali Khan ◽  
Dr. Shalini Yadav ◽  
◽  
...  

In the present work, analysis of concrete pavements using ANSYS software has been attempted. ANSYS is a finite element method-based software. The concrete slab has been modeled with solid 45 brick element and spring elements for soil. Analysis was carried out for a wide range of load and slab soil combination. The soil as “Winkler type” represented by elastic springs and their stiffness was derived from modulus of sub-grade reaction. The influence of any particular base or sub base on edge stresses was not studied here. The model will be then subjected to number of varying input parameters like the change in the thickness of pavement slab, sub-grade material to winkler foundation, modulus of elasticity by adding metal chips in different percentage like 10%, 20%, 30% and also intensity of loads. It is aimed to compare the stresses of the model study with classical approach of Westergaards and IRC 58- 2002 method. Westergaards equation under estimate edge wheel load stresses when compared with those obtained from ANSYS. For generating the charts, edge loading condition was considered which is critical case for wheel load stresses. Also, it was aimed to compare the results with those given by IRC 58 – 2002 design charts. Design charts were developed in thesis work yield the same value of pavement thickness as that of IRC 58 – 2002 method.

Author(s):  
Mohd. Imran Khan ◽  
◽  
Dr. Ahmad Ali Khan ◽  

In the present work, analysis of concrete pavements using ANSYS software has been attempted. ANSYS is a finite element method-based software. The concrete slab has been modeled with solid 45 brick element and spring elements for soil. Analysis was carried out for a wide range of load and slab soil combination. The soil as “Winkler type” represented by elastic springs and their stiffness was derived from modulus of sub-grade reaction. The influence of any particular base or sub base on edge stresses was not studied here. The model will be then subjected to number of varying input parameters like the change in the thickness of pavement slab, sub-grade material to winkler foundation, modulus of elasticity by adding metal chips in different percentage like 10%, 20%, 30% and also intensity of loads. It is aimed to compare the stresses of the model study with classical approach of Westergaards and IRC 58- 2002 method. Westergaards equation under estimate edge wheel load stresses when compared with those obtained from ANSYS. For generating the charts, edge loading condition was considered which is critical case for wheel load stresses. Also, it was aimed to compare the results with those given by IRC 58 – 2002 design charts. Design charts were developed in thesis work yield the same value of pavement thickness as that of IRC 58 – 2002 method.


2013 ◽  
Vol 61 (1) ◽  
pp. 111-121 ◽  
Author(s):  
T. Jankowiak ◽  
T. Łodygowski

Abstract The paper considers the failure study of concrete structures loaded by the pressure wave due to detonation of an explosive material. In the paper two numerical methods are used and their efficiency and accuracy are compared. There are the Smoothed Particle Hydrodynamics (SPH) and the Finite Element Method (FEM). The numerical examples take into account the dynamic behaviour of concrete slab or a structure composed of two concrete slabs subjected to the blast impact coming from one side. The influence of reinforcement in the slab (1, 2 or 3 layers) is also presented and compared with a pure concrete one. The influence of mesh density for FEM and the influence of important parameters in SPH like a smoothing length or a particle distance on the quality of the results are discussed in the paper


Author(s):  
Mohamad Ghodrati ◽  
Mehdi Ahmadian ◽  
Reza Mirzaeifar

A micromechanical-based 2D framework is presented to study the rolling contact fatigue (RCF) in rail steels using finite element method. In this framework, the contact patch of rail and wheel is studied by explicitly modeling the grains and grain boundaries, to investigate the potential origin of RCF at the microstructural level. The framework incorporates Voronoi tessellation algorithm to create the microstructure geometry of rail material, and uses cohesive zone approach to simulate the behavior of grain boundaries. To study the fatigue damage caused by cyclic moving of wheels on rail, Abaqus subroutines are employed to degrade the material by increasing the number of cycles, and Jiang-Sehitoglu fatigue damage law is employed as evolution law. By applying Hertzian moving cyclic load, instead of wheel load, the effect of traction ratio and temperature change on RCF initiation and growth are studied. By considering different traction ratios (0.0 to 0.5), it is shown that increasing traction ratio significantly increases the fatigue damage. Also by increasing traction ratio, crack initiation migrates from the rail subsurface to surface. The results also show that there are no significant changes in the growth of RCF at higher temperatures, but at lower temperatures there is a measurable increase in RCF growth. This finding correlates with anecdotal information available in the rail industry about the seasonality of RCF, in which some railroads report noticing more RCF damage during the colder months.


2016 ◽  
Vol 78 (5) ◽  
Author(s):  
Irpan Hidayat ◽  
Made Suangga ◽  
Fransiscus Leonardo ◽  
Godeliva Juliastuti

Concrete slab is a structural system that uses beams as a support element slab. The placement of beams at the whole edges of slab, so that the load received by the slab can be transfer into beams. The slab will be deformed/deflection when the loads are given. The value of slab deflection is dependent on the placement of beam support at the edges. This research was conducted on the two boundary condition that is simple support at the two edges and rigid support at whole edges. Calculating the value of deflection based on the results of field measurements and then compared with Marcus Levy method and Finite element method (FEM). Based on the study, the numbers of mesh affected to the value of deflection. The results of deflection with Program SAP 2000 will be approached deflection by Method M. Levy for the mesh division with large numbers. The deflection of slab on the field measurement approached manual calculations and Program SAP2000 with a simple support at the surrounding the edges.  The comparison of deflection was obtained for the simple support based on manual calculations and field measurement has a difference of 0.3% - 1%. Where the value of deflection on the field measurement is smaller than the manual calculation.


Author(s):  
Tatsuo Nishizawa ◽  
Tadashi Fukuda ◽  
Saburo Matsuno ◽  
Kenji Himeno

In the design of concrete pavement, curling stresses caused by the temperature difference between the top and bottom surfaces of the slab should be calculated at the transverse joint edge in some cases. However, no such equation has been developed in the past. Accordingly, a curling stress equation was developed based on stress analysis using the finite-element method (FEM). In this FEM analysis, a concrete pavement and its transverse joint were expressed by means of a thin plate–Winkler foundation model and a spring joint model, respectively. Multiregression analysis was applied to the results of the FEM numerical calculation and, consequently, a curling stress equation was obtained. After comparing the calculated results of the equation with curling stress equations developed in the past, it was confirmed that the equation was valid and practical.


1983 ◽  
Vol 14 (2) ◽  
pp. 85-92 ◽  
Author(s):  
Tilahun Aberra

The numerical solution of the behaviour of discrete time steps in digital computer analysis of square aquifers containing pumped wells is examined by using the finite element method with a 4 node linear quadrilateral isoparametric surface element. A wide range of time steps are used in the computation. The calculations show that discrete time steps can cause errors and oscillations in the calculations particularly when wells start and stop pumping. Comparison with known results obtained by theoretical and finite difference procedures has been considered. The main objective of this paper is to demonstrate comparison of the finite element and finite difference simulation results over a regular linear 4 node quadrilateral mesh suitable to represent the two numerical schemes with a marked similarity. The dimensionless time drawdown results of the finite element method agreed well with the finite difference and analytical results for small time increment. However, for large time increments, there are from slight to significant oscillations in the results and notable discrepancies are observed in the solutions of the two numerical methods.


2018 ◽  
Vol 4 (2) ◽  
pp. 61
Author(s):  
Yaprak Itır Özdemir

The purpose of this paper is to study free vibration analysis of thick plates resting on Winkler foundation using Mindlin’s theory with first order finite element, to determine the effects of the thickness/span ratio, the aspect ratio, subgrade reaction modulus and the boundary conditions on the frequency parameters of thick plates subjected to free vibration. In the analysis, finite element method is used for spatial integration. Finite element formulation of the equations of the thick plate theory is derived by using first order displacement shape functions. A computer program using finite element method is coded in C++ to analyze the plates free, clamped or simply supported along all four edges. In the analysis, 4-noded finite element is used. Graphs are presented that should help engineers in the design of thick plates subjected to earthquake excitations. It is concluded that 4-noded finite element can be effectively used in the free vibration analysis of thick plates. It is also concluded that, in general, the changes in the thickness/span ratio are more effective on the maximum responses considered in this study than the changes in the aspect ratio.


Author(s):  
Andrew W. Hulton ◽  
Paul V. Cavallaro

Fiber reinforced polymer (FRP) composites have been used as a substitute for more conventional materials in a wide range of applications, including in the aerospace, defense, and auto industries. Due to the widespread availability of measurement techniques, experimental testing of composite materials has outpaced the computational modeling ability of such complicated materials. With advancements in computational physics-based modeling (PBM) such as the finite element method (FEM), strides can be made to reduce the efforts required in building and testing future composite structures. In this work, the extended finite element method (XFEM) is implemented to model fracture of composite materials under quasistatic loading. XFEM is applied to a three-dimensional (3D) computational model of a carbon fiber/epoxy composite cylinder, in half symmetry, that is subjected to lateral compression between two flat plates. Independent material properties are instituted for each composite layer, depending on individual layer orientation. The crack path produced by the analytical results is compared to experimental testing of lateral compression of a composite cylinder. Fracture site initiation and growth path are consistent in both the experimental and computational results.


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