Mechanical Behavior of Ultrathin Whitetopping Structure Under Stationary and Moving Loads

2003 ◽  
Vol 1823 (1) ◽  
pp. 102-110 ◽  
Author(s):  
Tatsuo Nishizawa ◽  
Yoshiki Murata ◽  
Katsuro Kokubun
Keyword(s):  
Load Transfer ◽  
Concrete Slab ◽  
Three Dimensional ◽  
Element Model ◽  
Interface Condition ◽  
Interface Element ◽  
Concrete Slabs ◽  
Moving Loads ◽  
Mechanical Interaction ◽  
Loading Test

The structural design of ultrathin whitetopping (UTW) requires precise predictions of the loading stresses in the concrete slabs. A plate finite element model (FEM) is not used for structures with UTW because the model is not able to account for the asphalt subbase behaviors and the mechanical interaction between the concrete slab and asphalt subbase. A three-dimensional FEM (3DFEM) was used for the stress calculation of UTW. To take into account the mechanical interaction at the interface between the concrete slab and asphalt subbase as well as the load transfer across the joint, a general interface element was developed and incorporated into 3DFEM. Also, the viscosities of asphalt materials were considered by the viscoelastic formulation in the 3DFEM. A loading test was conducted on a test pavement. Stationary and moving loads were applied to the concrete slabs, and the strains in the slabs and the asphalt subbase were measured. By comparing the strains computed by 3DFEM with the measured strains, it was found that the viscosity of the asphalt subbase and the interface condition significantly affect the stresses in the concrete slab.

Research on Load Transfer Efficiency of GFRP Dowel in Jointed Plain Concrete Pavement

2012 ◽  
Vol 178-181 ◽  
pp. 1152-1155 ◽  
Author(s):  
Luo Ke Li ◽  
Yun Liang Li ◽  
Yi Qiu Tan ◽  
Zhong Jun Xue
Keyword(s):  
Finite Element ◽  
Load Transfer ◽  
Concrete Slab ◽  
Three Dimensional ◽  
Plain Concrete ◽  
Element Model ◽  
Transfer Efficiency ◽  
Engineering Practice ◽  
Concrete Pavements ◽  
Load Transfer Efficiency

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.

scholarly journals Three-Dimensional Dynamic Analyses of Track-Embankment-Ground System Subjected to High Speed Train Loads

2014 ◽  
Vol 2014 ◽  
pp. 1-19 ◽  
Author(s):  
Qiang Fu ◽  
Changjie Zheng
Keyword(s):  
Dynamic Response ◽  
High Speed ◽  
Concrete Slab ◽  
Three Dimensional ◽  
Element Model ◽  
Moving Loads ◽  
Infinite Elements ◽  
Ground System ◽  
High Speed Trains ◽  
Train Speed

A three-dimensional finite element model was developed to investigate dynamic response of track-embankment-ground system subjected to moving loads caused by high speed trains. The track-embankment-ground systems such as the sleepers, the ballast, the embankment, and the ground are represented by 8-noded solid elements. The infinite elements are used to represent the infinite boundary condition to absorb vibration waves induced by the passing of train load at the boundary. The loads were applied on the rails directly to simulate the real moving loads of trains. The effects of train speed on dynamic response of the system are considered. The effect of material parameters, especially the modulus changes of ballast and embankment, is taken into account to demonstrate the effectiveness of strengthening the ballast, embankment, and ground for mitigating system vibration in detail. The numerical results show that the model is reliable for predicting the amplitude of vibrations produced in the track-embankment-ground system by high-speed trains. Stiffening of fill under the embankment can reduce the vibration level, on the other hand, it can be realized by installing a concrete slab under the embankment. The influence of axle load on the vibration of the system is obviously lower than that of train speed.

Dynamic Performance Analysis for a Butterfly-Shaped Arch Bridge

2010 ◽  
Vol 163-167 ◽  
pp. 74-78
Author(s):  
Hai Yun Huang ◽  
Xiang Rong Yuan ◽  
Ka Hong Cai
Keyword(s):  
Dynamic Analysis ◽  
Dynamic Characteristics ◽  
Dynamic Performance ◽  
Three Dimensional ◽  
Element Model ◽  
Loading Test ◽  
Structural Dynamic ◽  
Arch Bridge ◽  
Calculation Results ◽  
Dynamic Performance Analysis

The dynamic characteristics are not only the important indexes for evaluating the bridge structural rigidity, but also the principal parameters for structural dynamic analysis and earthquake resistant analysis. In this paper, a three dimensional solid finite element model for a butterfly-shape arch bridge in Zhongshan city was established to analyze the dynamic characteristics. By comparison the numerical calculation results with measured results of the dynamic loading test, an analysis and evaluation of the dynamic performance of this new type spatial arch bridge was made, and can serve as reference to the dynamic analysis and seismic design of similar bridges.

scholarly journals Significance of geotechnical loads on local buckling response of buried pipelines with respect to conventional practice

2013 ◽  
Vol 50 (1) ◽  
pp. 68-80 ◽  
Author(s):  
Hiva Mahdavi ◽  
Shawn Kenny ◽  
Ryan Phillips ◽  
Radu Popescu
Keyword(s):  
Load Transfer ◽  
Mechanical Performance ◽  
Three Dimensional ◽  
Local Buckling ◽  
Element Model ◽  
Combined Loading ◽  
Buried Pipelines ◽  
Buried Pipe ◽  
Limit States ◽  
New Criterion

Long-term large deformation geohazards can impose excessive deformation on a buried pipeline. The ground displacement field may initiate pipeline deformation mechanisms that exceed design acceptance criteria with respect to serviceability requirements or ultimate limit states. The conventional engineering approach to define the mechanical performance of pipelines has been based on combined loading events for in-air conditions. This methodology may be conservative, as it ignores the soil effect that imposes geotechnical loads, and also provides restraint, on buried pipelines. The importance of pipeline–soil interaction and load-transfer mechanisms that may affect local buckling of buried pipelines is not well understood. A three-dimensional continuum finite element model, simulating the local buckling response of a buried pipe, using the software package ABAQUS/Standard was developed and calibrated. A comprehensive parametric study was previously conducted to investigate the effect of several parameters on local buckling response of pipelines buried in firm clay. A new strain criterion for local buckling of buried pipelines in firm clay through response surface methodology was developed. In this paper, the new criterion is compared with several existing in-air criteria to study the effect of soil restraint on the local buckling response of buried pipelines. The criterion developed in this study predicts greater characteristic critical strain capacity than in-air based criteria that highlights the influence of soil restraint.

Load Transfer Analysis of Cracked Bolted Joints

2010 ◽  
Vol 118-120 ◽  
pp. 147-150
Author(s):  
Da Zhao Yu ◽  
Yue Liang Chen ◽  
Yong Gao ◽  
Wen Lin Liu ◽  
Zhong Hu Jia
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Load Transfer ◽  
Three Dimensional ◽  
Element Model ◽  
Bolted Joints ◽  
Bolted Joint ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Three-dimensional finite element model of a cracked bolted joint has been developed in the non-linear finite element code MSC.Marc and attempts were made to validate it by comparing results with those of experiments and other finite element. Issues in modeling the contact between the joint parts, which affect the accuracy and efficiency of the model, were presented. Experimental measurements of load transfer were compared with results from finite element analysis. The results show that three-dimensional finite element model of cracked bolted joint can produce results in close agreement with experiment. Three-dimensional effects such as bolt titling, seconding and through-thickness variations in stress and strain are well represented by such models. Three-dimensional finite element analysis was also used to study the effects of hole mod and crack on the load transfer behaviour of single lap bolted joints. The results show that hole mode has big effect on load transfer of cracked bolted joint. In the whole progress of crack growth, the load transfer through bolt 1 decrease, and almost all of the load duduction of bolt 1 transfer into blot 2 rather than into bolt 3.

scholarly journals The calculation of anchors in steel-concrete overlaps with precast slab

2019 ◽  
Vol 97 ◽  
pp. 06022
Author(s):  
Alexander Tusnin ◽  
Alexey Kolyago
Keyword(s):  
Reinforced Concrete ◽  
Cross Section ◽  
Concrete Slab ◽  
Element Model ◽  
Calculation Model ◽  
Concrete Slabs ◽  
Steel Beams ◽  
Steel Beam ◽  
Practical Application ◽  
Reinforced Concrete Slabs

Reinforced concrete floors and steel beams are widely used in buildings and structures for various purposes. Reinforced concrete overlaps can be cast-in or precast of hollow-core slabs. The most effective floors in which the concrete slab is located in the compressed area of cross-section, in steel beams in the tension zone, and shifting forces, arising between concrete slab and the steel beam, are perceived by anchors. Precast slabs in comparison with cast-in ones have less labor-intensive performance, the beam spacing is equal to the span of reinforced concrete slabs, there are no intermediate beams in such overlaps, that allows to reduce the floor thickness. The inclusion of precast in steel-concrete cross-section requires joints with steel beams, which requires using of special anchors. Anchor perceives shear forces and ensures the joint operation of the plate and the steel beam. In addition, for beams with narrow flange, the anchor device can provide the required width of the support slabs. The calculation of the attachment points of the anchors to the steel beam is carried out using three variants of calculation methods, which allow to determine the forces acting on the anchor. For practical application, a wire-element model has been proposed and managed to get forces in a steel beam, slab and anchors the width of the slab recommended by the standards should be included in the calculation model.

Finite Element Study of Settlement of Cement Mixing Composite Foundation and Non-Probabilistic Reliability Analysis

2014 ◽  
Vol 638-640 ◽  
pp. 675-679 ◽  
Author(s):  
Huan Sheng Mu ◽  
Ling Gao
Keyword(s):  
Finite Element ◽  
Reliability Analysis ◽  
Load Transfer ◽  
Soft Soil ◽  
Probabilistic Method ◽  
Three Dimensional ◽  
Element Model ◽  
Composite Foundation ◽  
Reliability Method ◽  
Three Dimensional Finite Element

This paper presents a non-probabilistic method for reliability analysis of cement mixing composite foundations. First, the load transfer mechanism of composite foundations is described. Then a three-dimensional finite element model of cement mixing composite foundation under embankment is built. The settlement of subgrade is analyzed. Finally, a non-probabilistic reliability method is used to investigate the settlement reliability. The results show that the cement mixing composite foundation can significantly improve the compressibility of soft soil.

Prediction of Potential Cracking Failure Modes in Three-Dimensional Airfield Rigid Pavements with Existing Cracks and Flaws

2012 ◽  
Vol 2266 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Francisco Evangelista ◽  
Jeffery R. Roesler ◽  
C. Armando Duarte
Keyword(s):  
Failure Modes ◽  
Concrete Slab ◽  
Three Dimensional ◽  
Fatigue Cracking ◽  
Crack Size ◽  
Concrete Slabs ◽  
Shear Mode ◽  
Generalized Finite Element Method ◽  
Top Down ◽  
Bottom Up

This paper predicts the potential for crack propagation in concrete pavements under aircraft loading given a starter fatigue crack at the bottom of the concrete slab or a surface-initiated shrinkage crack on top of the slab. The generalized finite element method was used to evaluate the stress intensity factors for quarter elliptical cracks placed at the critical top and bottom tensile stress locations. The pavement was loaded with a single triple-dualtandem (TDT) gear and two TDTs accounting for the entire belly gears. When the pavement was loaded with the two TDT gear configuration, the analyses showed significantly higher KI (shear mode) values for surface-initiated cracks than for bottom-initiated cracks for the same crack size. Therefore, concrete slabs with preexisting surface cracks are more likely to exhibit top-down crack growth despite being designed for bottom-up fatigue cracking under certain loading conditions. The theoretical framework allows for improved assessment of the fracture susceptibility of concrete slabs under aircraft loading, specifically the potential for top-down over bottom-up cracking.

scholarly journals The Partitioned Mixed Model of Finite Element Method and Interface Stress Element Method with Arbitrary Shape of Discrete Block Element

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Zhang Qing ◽  
Zhuo Jiashou ◽  
Xia Xiaozhou
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Arbitrary Shape ◽  
Mixed Model ◽  
Three Dimensional ◽  
Element Model ◽  
Interface Stress ◽  
Interface Element ◽  
Spring Element ◽  
Element Method

Based on the model of rigid-spring element suitable for homogeneous elastic problem, which was developed by Japanese professor Kawai, the interface stress element model (ISEM) for solving the problem of discontinuous media mechanics has been established. Compared with the traditional finite element method (FEM), the ISEM is more accurate and applicable. But the total number of freedom degree of ISEM in dealing with three-dimensional problems is higher than that of FEM, which often brings about the reduction on efficiency of calculation. Therefore, it is necessary to establish a mixed model by gathering the advantages of ISEM and FEM together. By making use of the good compatibility of ISEM and introducing the concept of transitional interface element, this paper combines ISEM and FEM and proposes a mixed model of ISEM-FEM which can solve, to a large extent, the contradictions between accuracy and efficiency of calculation. In addition, using natural coordinate, algorithm of ISEM for block elements of arbitrary shape has been performed. Numerical examples show that the method proposed in this paper is feasible and its accuracy is satisfactory.

Three-Dimensional Finite Element Analysis of Doweled Joints for Airport Pavements

2003 ◽  
Vol 1853 (1) ◽  
pp. 100-109 ◽  
Author(s):  
Jiwon Kim ◽  
Keith D. Hjelmstad
Keyword(s):  
Finite Element ◽  
Load Transfer ◽  
Concrete Slab ◽  
Three Dimensional ◽  
Nonlinear Material ◽  
Structural Behavior ◽  
Loading Conditions ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Analytical Approaches

Various aspects of the structural behavior of doweled joints, including load transfer, in rigid airport pavement systems are investigated by using nonlinear three-dimensional finite element methods. The finite element models include two concrete slab segments connected by dowels. The concrete slab and supporting layers are simulated by continuum solid elements. Solid elements can capture the severe local deformation in the concrete slab in the vicinity of wheel loads. They allow the modeling of nonlinear material response of the supporting layers and of frictional contact between the concrete slabs and supporting layers. These features generally are not considered in classical analytical approaches. The structural behavior of the doweled joint is investigated for various design and loading conditions, including tire pressure, slab thickness, dowel looseness, and different landing gear configurations. An attempt is made to quantify the amount and efficiency of load transfer through the dowels. According to the finite element results, 15% to 30% of the applied wheel load is transferred to the adjacent slab segment by the dowels in an intact joint, depending on design and loading conditions. In addition, 95% of the transferred shear force is carried only by the 9 or 11 dowels that are closest to the applied load.

Sign in / Sign up

Export Citation Format

Share Document