Damage Mechanics Model for Fracture Process of Steel-Concrete Composite Slabs

2012 ◽  
Vol 165 ◽  
pp. 339-345 ◽  
Author(s):  
M. Joshani ◽  
S.S.R. Koloor ◽  
Redzuan Abdullah
Keyword(s):  
Finite Element ◽  
Damage Mechanics ◽  
Plain Concrete ◽  
Element Model ◽  
Interface Layer ◽  
Building Structures ◽  
Horizontal Shear ◽  
Composite Slab ◽  
Damage And Fracture ◽  
Composite Slabs

Composite slab construction using permanent cold-formed steel decking has become one of the most economical and industrialized forms of flooring systems in modern building structures. Structural performance of the composite slab is affected directly by the horizontal shear bond phenomenon at steel-concrete interface layer. This study utilizes 3D nonlinear finite element quasi-static analysis technique to analyze the shear bond damage and fracture mechanics of the composite slabs. Fracture by opening and sliding modes of the plain concrete over the corrugated steel decking had been modeled with concrete damaged plasticity model available in ABAQUS/Explicit module. The horizontal shear bond was simulated with cohesive element. Cohesive fracture properties such as fracture energy and initiation stress were derived from horizontal shear bond stress versus end slip curves. These curves were extracted from bending tests of narrow width composite slab specimens. Results of the numerical analyses match the experimental results accurately. This study demonstrated that the proposed finite element model and analysis procedure can predict the behavior of composite slabs accurately. The procedure can be used as a cheaper alternative to experimental work for investigating the ultimate strength and actual fracture and damage behavior of steel-concrete composite slab systems.

Blast loaded steel-concrete composite slab

2021 ◽  
Vol 15 (1) ◽  
pp. 7874-7884
Author(s):  
Aizat Alias ◽  
A.F.M. Amin
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Coefficient Of Friction ◽  
Element Model ◽  
Blast Loads ◽  
Blast Pressure ◽  
Composite Slab ◽  
Composite Slabs ◽  
Mode Of Failure ◽  
The Coefficient Of Friction

This paper presented a numerical investigation of a steel-concrete composite slab subjected to blast loads. The finite element model of the composite slab was developed and validated against experimental results. The validated finite element model of the composite slab then subjected to blast loads using CONWEP function in ABAQUS. A validation investigation was performed on CONWEP function by comparing the blast-pressure profiles from CONWEP against experimental data. Both validation studies showed that the developed finite element model of the composite slab and CONWEP agree reasonably well with test results. The fully restrained composite slab was subjected to four different blast loads with different explosive weights and standoff distances. The transient deformation of the composite slab after subjected to blast loads was investigated where as predicted the deformation of the composite slab was influenced by the blast pressure, which is affected by the weight of explosive and standoff distance. This study also investigated the mode of failure where it was determined flexural failure at the midspan is the main mode of failure accompanied with concrete tensile failure at the supports. The thickness of the profiled deck and the coeffecient of friction influenced the dynamic response of the composite slabs. Increasing the thickness reduces the maximum displacement of the composite slabs. Increasing the coefficient of friction reduces the maximum dislacement but once the coefficient of friction reach its optimum value, no positive benefit is gained.

scholarly journals COMPRESSED ELEMENTS WITH A VARIABLE IN LENGTH STIFFNESS EQUILIBRIUM FORM STABILITY DETERMINATION

2019 ◽  
Vol 2 (53) ◽  
pp. 30-36
Author(s):  
Oleksandr Shkurupiy ◽  
Pavlo Mytrofanov ◽  
Yuriy Davydenko ◽  
Muhlis Hajiyev
Keyword(s):  
Finite Element ◽  
Critical Load ◽  
Discrete Systems ◽  
Element Model ◽  
Stability Loss ◽  
Building Structures ◽  
Displacement Method ◽  
Equilibrium Form ◽  
Stability Calculation ◽  
Complex Building

One of the most powerful modern methods of calculating complex building structures is the finite element method in theform of a displacement method for discrete systems, which involves the creation of a finite element model, that is, splittingthe structure into separate elements within each of which the functions of displacements and stresses are known. On the basisof the displacement method and the methods of iterations and half-division, an algorithm for stability calculation of the firstkind equilibrium form of compressed reinforced concrete columns with hinged fixing at the ends, considering the stiffnesschanging has been developed. The use of the above methods enables to determine the minimum critical load or stress at thefirst bifurcation and their stability loss corresponding form. The use of matrix forms contributes to simplification of high order stability loss equation. This approach enables to obtain the form of stability loss that corresponds to the critical load.

scholarly journals Failure Analysis of Composite Pinned Joints Based on Continuum Damage Mechanics

2018 ◽  
Vol 36 (5) ◽  
pp. 848-855
Author(s):  
Hongliang Tuo ◽  
Xiaoping Ma ◽  
Zhixian Lu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Damage Mechanics ◽  
Continuum Damage Mechanics ◽  
Element Model ◽  
Fracture Plane ◽  
Continuum Damage ◽  
Bearing Strength ◽  
Matrix Damage ◽  
Pinned Joints

The paper conducted bearing tests on composite pinned joints with four different stacking sequences. The bearing strength and bearing chord stiffness were obtained. The influence of stacking sequences on failure modes, bearing strength and bearing chord stiffness was discussed. Based on continuum damage mechanics, a three-dimensional finite element model of composite pinned joint under bearing load was built, where the maximum strain criterion was employed for initiation and bi-liner damage constitutive relation for revolution of fiber damage, while the physical-based Puck criterion was used for matrix damage initiation, and matrix damage revolution depended on the effective strain on the fracture plane. The failure mode, bearing strength and bearing chord stiffness of composite pinned joint were discussed with this model under which the non-linear shear behavior and in-situ strength effects were considered. Good agreements between test results and numerical simulations validates the accuracy and applicability of the finite element model.

Evaluation of Dynamic Behaviors and Damage Mechanism of Ancient Timber Architectures

2007 ◽  
Vol 340-341 ◽  
pp. 277-282 ◽  
Author(s):  
Ai Lan Che ◽  
Xiu Run Ge ◽  
Takahiro Iwatate
Keyword(s):  
Finite Element ◽  
Damage Mechanics ◽  
Structural Characteristics ◽  
Experimental Studies ◽  
Element Model ◽  
Damage Mechanism ◽  
Observation Data ◽  
Element Group ◽  
Structural Resistance ◽  
Mortise And Tenon

An urgent is needed on the preservation of Chinese architectural heritages, since environmental and time impacts have been abating their structural resistance capability. It is of great importance in protecting and rehabilitating the ancient architectural culture of China to study the structural characteristics of ancient Chinese timber architectures. As a typical example of ancient timber architectures-Yingxian Wooden Pagoda in west of Shanxi Prince, the dynamic characteristics and damage mechanics of the tower are investigated experimentally and numerically by micro tremor measurements and means of finite-element-method (FEM). The micro tremor measurements are conducted on the tower (each floor) and the surrounding ground. From the micro tremor observation data, the predominant frequency of the surface ground and natural frequency, vibration mode and the damage distribution characteristics of the tower were evaluated. Based on the experimental studies, the tower is created by a delicate finite element model. And in order to simulate the mortise and tenon joint---bucket arches in the structure, which is a combination of a series of timber structures, a special beam-element group is developed. Numerical simulation of the seismic response of the tower shows that the second and third floors of the tower would be damaged more seriously than other floors for their severe stresses when acted by seismic loading. The present analysis of the tower shows the same phenomena. The results provide basis for repairing and reinforcing the ancient timber tower.

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 Nonlinear finite element analysis of profiled steel deck composite slab system under monotonic loading.

2021 ◽  
Author(s):  
Shubhangi Attarde
Keyword(s):  
Finite Element ◽  
Mesh Size ◽  
Monotonic Loading ◽  
Nonlinear Finite Element ◽  
Experimental Results ◽  
Model Parameters ◽  
Element Analysis ◽  
Composite Slab ◽  
Composite Slabs ◽  
Steel Deck

This research concentrated on the nonlinear finite element (FE) modeling of one-way composite floor slab system comprising of profiled steel deck and two types of concrete namely, Engineered Cementitious Composites (ECC) and Self-Consolidating Concrete (SCC). Two FE models were developed based experimental results of composite slabs subjected to in-plane monotonic loading. The simulated load-deflection response, moment resistance, and shear bond capacity using two FE models were in reasonable good agreement with experimental results. The FE models were used in a comprehensive parametric study to investigate the effect of numerical model parameters such as mesh size, dilation angle, steel sheet-concrete interaction contact, material properties and composite slab span. In addition, FE models were used to determine shear bond parameters of ECC and SCC composite slabs that can be used for design purposes.

scholarly journals Modelling lead-rubber seismic isolation bearings using the unified mechanics theory

2021 ◽  
Vol 4 (4) ◽  
pp. 213-226
Author(s):  
Hernán Martín Hernández Morales
Keyword(s):  
Finite Element ◽  
Curve Fitting ◽  
Seismic Isolation ◽  
Damage Mechanics ◽  
Element Model ◽  
Hysteretic Behavior ◽  
Newtonian Mechanics ◽  
Element Analysis ◽  
Lead Rubber Bearing ◽  
Period Lengthening

Lead-rubber seismic isolation bearings (LRB) have been installed in a number of essential and critical structures, like hospitals, universities and bridges, in order to provide them with period lengthening and the capacity of dissipating a considerable amount of energy to mitigate the effects of strong ground motions. Therefore, studying the damage mechanics of this kind of devices is fundamental to understand and accurately describe their thermo-mechanical behavior, so that seismically isolated structures can be designed more safely. Hitherto, the hysteretic behavior of LRB has been modeled using 1) Newtonian mechanics and empirical curve fitting degradation functions, or 2) heat conduction theories and idealized bilinear curves which include degradation effects. The reason for using models that are essentially phenomenological or that contain some adjusted parameters is the fact that Newton’s universal laws of motion lack the term to account for degradation and energy loss of a system. In this paper, the Unified Mechanics Theory – which integrates laws of Thermodynamics and Newtonian mechanics – is used to model the force-displacement response of LRB. Indeed, there is no need for curve fitting techniques to describe their damage behavior because degradation is calculated at every point using entropy generation along the Thermodynamics State Index (TSI) axis. A finite element model of a lead-rubber bearing was constructed in ABAQUS, where a user material subroutine UMAT was implemented to define the Unified Mechanics Theory equations and the viscoplastic constitutive model for lead. Finite element analysis results were compared with experimental test data.

Three-Dimensional Finite Element Analysis of Jointed Plain Concrete Pavement with EverFE2.2

2003 ◽  
Vol 1853 (1) ◽  
pp. 92-99 ◽  
Author(s):  
William G. Davids ◽  
Zongmu Wang ◽  
George Turkiyyah ◽  
Joe P. Mahoney ◽  
David Bush
Keyword(s):  
Finite Element ◽  
Load Transfer ◽  
Three Dimensional ◽  
Plain Concrete ◽  
Horizontal Shear ◽  
Base Shear ◽  
Transverse Joint ◽  
Dimensional Finite Element ◽  
Joint Load ◽  
Three Dimensional Finite Element

The features and concepts underlying EverFE2.2, a freely available three-dimensional finite element program for the analysis of jointed plain concrete pavements, are detailed. The functionality of EverFE has been greatly extended since its original release: multiple tied slab or shoulder units can be modeled, dowel misalignment or mislocation can be specified per dowel, nonlinear thermal or shrinkage gradients can be treated, and nonlinear horizontal shear stress transfer between the slabs and base can be simulated. Improvements have been made to the user interface, including easier load creation, user-specified mesh refinement, and expanded visualization capabilities. These new features are detailed, and the concepts behind the implementation of EverFE2.2 are explained. In addition, the results of two parametric studies are reported. The first study considers the effects of dowel locking and slab-base shear transfer and demonstrates that these factors can significantly affect the stresses in slabs subjected to both uniform shrinkage and thermal gradients. The second study examines transverse joint mislocation and dowel looseness on joint load transfer. As expected, joint load transfer is greatly reduced by dowel looseness. However, while transverse joint mislocation can significantly reduce peak dowel shears, it has relatively little effect on total load transferred across the joint for the models considered.

scholarly journals Numerical Simulation and Parametric Analysis of Fatigue Crack in UIC60 Rail Thermite Welded Joint

2021 ◽  
Vol 1206 (1) ◽  
pp. 012027
Author(s):  
Prakash Kumar Sen ◽  
Mahesh Bhiwapurkar ◽  
S P Harsha
Keyword(s):  
Finite Element ◽  
Fatigue Crack ◽  
Fatigue Life ◽  
Damage Mechanics ◽  
Three Dimensional ◽  
Element Model ◽  
Scale Model ◽  
Dimensional Solution ◽  
Diagnostic Skills ◽  
Analysis Technique

Abstract The mechanism of rail-wheel contact is the most essential field of study in railway engineering since it requires extensive application expertise, diagnostic skills, and a trustworthy analysis technique. In this research the fatigue life of a UIC60 rail AT weld under vertical load and its parametric effect has been studied, and for that a three-dimensional elastic-plastic finite element model is created using ANSYS space-claim software, and then finite element method is employed to analyse the full-scale model of wheel-track and weld system with realistic three-dimensional solution. Model assembly components include axle, wheel, and thermite-welded rail. Simulation of contact between wheel and UIC60 rail weld with crack on weld at angles of 30 and 60 degrees with different coefficients of friction between the weld wheel contact and between crack surfaces was carried out under vertical loadings. In general, the Hertz contact theory assumptions are taken into consideration throughout the analysis, and the impacts on fatigue life are given by using damage mechanics method. The results of the wheel/weld fatigue crack analysis have been displayed to demonstrate the influence of different parameters on the fatigue life of cracks. The purpose of this study is to identify and safeguard the rail against failure, as well as to ensure the safety of passengers and to reduce the cost of maintaining the rail system.

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