A Damage Analysis of Steel-Concrete Composite Beams Via Dynamic Methods: Part I. Experimental Results

2003 ◽  
Vol 9 (5) ◽  
pp. 507-527 ◽  
Author(s):  
Antonino Morassi ◽  
Luigi Rocchetto
Keyword(s):  
Damage Identification ◽  
Concrete Slab ◽  
Dynamic Test ◽  
Flexural Vibration ◽  
High Sensitivity ◽  
Composite Beams ◽  
Experimental Results ◽  
Reinforced Concrete Slab ◽  
Dynamic Methods ◽  
Induced Changes

This paper is an experimental investigation on damage-induced changes in modal parameters of steel-concrete composite beams subject to small vibrations. Dynamic tests have been performed on two pairs of composite beams, whose connections have different linear densities, and three damage configurations for each beam have been analyzed. Damage was induced by removing concrete around some elements connecting the steel beam and the reinforced concrete slab and consequently causing a lack of structural solidarity between the two beams. Experiments revealed that: (i) unlike axial frequencies, flexural frequencies show a rather high sensitivity to damage and therefore can be considered as a valid indicator upon a diagnostic analysis; (ii) induced damage causes the nodes of flexural vibration modes to displace towards the damaged area; (iii) in addition to hindering relative sliding on the concrete-steel interface, the elements connecting the slab and the metallic beam play a key role in reducing transversal motions between the two beams. These experimental results were crucial to outline an accurate analytical model of the dynamic behavior of composite beams with damaged connectors and to formulate a diagnostic problem from dynamic test data. Part II of this research will deal with mechanical modeling of damaged composite beams and damage identification.

A Damage Analysis of Steel-Concrete Composite Beams Via Dynamic Methods: Part II. Analytical Models and Damage Detection

2003 ◽  
Vol 9 (5) ◽  
pp. 529-565 ◽  
Author(s):  
Michele Dilena ◽  
Antonino Morassi
Keyword(s):  
Damage Detection ◽  
Dynamic Behavior ◽  
Concrete Slab ◽  
Composite Beams ◽  
Analytical Investigation ◽  
Experimental Results ◽  
Analytical Models ◽  
Reinforced Concrete Slab ◽  
Dynamic Methods ◽  
Positive Results

This paper is the second part of an experimental-analytical investigation on the dynamic behavior of damaged steel-concrete composite beams. In the first part of the research, we presented and discussed the experimental results of a comprehensive series of dynamic tests performed on composite beams with damage in the connection. Experimental observations suggested the formulation of a composite beam analytical model, where the strain energy density of the connection also includes an energy term associated to the occurrence of relative transversal displacements between the reinforced concrete slab and the steel beam. A comparison with experimental results shows that the model enhances accuracy in describing the undamaged state of composite beams and that it is also appropriate to accurately predict the dynamic behavior under damaged conditions. A damage detection technique based on the measurement of variation in the first flexural frequencies was then applied to the suggested model and gave positive results.

scholarly journals Serviceability limit state of two-way reinforced concrete slab strengthened with different techniques

2018 ◽  
Vol 162 ◽  
pp. 04001
Author(s):  
Eyad Sayhood ◽  
Ammar Ali ◽  
Zahraa Sharhan
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Limit State ◽  
Experimental Results ◽  
Bottom Surface ◽  
Reinforced Concrete Slab ◽  
Near Surface ◽  
Reinforced Concrete Slabs ◽  
Concrete Layer ◽  
Near Surface Mounted

The experimental results for service load of sixteen simply supported two way reinforced concrete slabs under the action of concentrated patch load were determined based on the amount of permissible deflections and the crack widths.All the slabs had the same overall dimensions and flexural steel reinforcement. Five types of strengthening were adopted. The first and second methods include applying either near surface mounted (NSM) or near reinforcement mounted (NRM) ferrocement layers. While the third method includes applying a concrete layer reinforced with welded wire fabric mesh of various diameters. The fourth and fifth methods include fixing CFRP rods and laminates, respectively, on the bottom surface of slabs. Strengthening techniques were applied on the bottom surface of fifteen slab specimens. In addition, a control slab specimen without any strengthening was used for the purpose of comparison. The calculated results for ultimate loads based on serviceability requirements (deflection and crack width according to both ACI and BS formulae) were lower than the experimental results.

scholarly journals Optimal Design of Steel–Concrete Composite Beams Strengthened under Load

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4715
Author(s):  
Piotr Szewczyk ◽  
Maciej Szumigała
Keyword(s):  
Numerical Models ◽  
Concrete Slab ◽  
Plate Thickness ◽  
Steel Part ◽  
Composite Beams ◽  
Steel Plates ◽  
Reinforced Concrete Slab ◽  
Recoverable Strain ◽  
Bending Capacity ◽  
Optimum Solution

This paper presents results of numerical analysis and experimental research on strengthening of steel–concrete composite beams. Studied members consisted of IPE200 I-beam and 90 × 700 mm reinforced concrete slab. The steel part of the section was strengthened by welding additional steel plates at the bottom. The study was performed for plate thickness ranging between 6 to 22 mm. Spatial FEM models were developed to account for material and geometric nonlinearities and for stress and post-welding strain. Proposed numerical models were experimentally validated. One aim was to find an optimum solution which would minimize cost and maximize bending capacity. To achieve this, energy parameters available in numerical simulations were reviewed and analyzed. Recoverable strain energy value determined in Abaqus was used to find the optimum solution.

scholarly journals Plate with holes as shear connector in cold formed steel composite beams

2019 ◽  
Vol 12 (3) ◽  
pp. 509-517
Author(s):  
O. P. AGUIAR ◽  
R. B. CALDAS ◽  
F. C. RODRIGUES ◽  
H. N .BELLEI
Keyword(s):  
Concrete Slab ◽  
Composite Beams ◽  
Shear Connector ◽  
Reinforced Concrete Slab ◽  
Relative Slip ◽  
Floor Systems ◽  
Composite Section ◽  
Support Area ◽  
Steel Composite ◽  
Cold Formed Steel

Abstract In search of an improved compatibility between cold-formed steel profiles and precast floor systems, this study proposes an alternative shear connector for cold-formed steel-concrete composite beams. This connector consists of a steel plate with holes placed longitudinally in the middle of the upper flange of the steel profile, aiming to maximize the support area for precast slabs during the assembly. The proposed solution was experimentally tested on I-beams under bending, composed by two cold-formed steel channels, connected to a reinforced concrete slab by the shear connector. The relative slip between the steel profile and concrete, vertical deflection of the beam, and strains at several locations of the composite section were measured. The results show that the proposed connector assures shear transfer at the interface of the composite section components and shows strength of the same magnitude as other commonly used connectors.

scholarly journals SIMULAÇÃO NÚMERICA DO COMPORTAMENTO DE VIGAS MISTAS DE AÇO E CONCRETO PROTENDIDAS [ Numerical behavior analysis of prestressed steel-concrete composite beams ]

2018 ◽  
Vol 15 (1) ◽  
Author(s):  
Elder Nogueira Da Silva ◽  
Alex Sander Clemente De Souza
Keyword(s):  
Finite Element ◽  
Numerical Model ◽  
Finite Elements ◽  
Composite Beam ◽  
Concrete Slab ◽  
Constitutive Relations ◽  
Composite Beams ◽  
Experimental Results ◽  
Finite Element Models ◽  
Shear Connectors

RESUMO: O presente trabalho apresenta uma metodologia para análise numérica de vigas mistas de aço e concreto protendidas utilizando o pacote computacional ABAQUS®, que permite modelagens via método dos elementos finitos. A metodologia aborda aspectos relacionados a escolha dos elementos finitos utilizados, geometria das malhas, relações constitutivas dos materiais, condições de acoplamento e vinculação entre os materiais e procedimentos de aplicação dos carregamentos, com o objetivo de simular o comportamento da estrutura. A interação entre laje de concreto e viga de aço foi modelada com conectores e elementos de contato e considerando somente o acoplamento das redes de elementos finitos da laje e da viga. A validação do modelo numérico foi realizada através da correlação entre os resultados numéricos e experimentais disponíveis na literatura. Para ambas as formas de vinculação laje-perfil, o modelo numérico representou de forma satisfatória o comportamento observado experimentalmente. Nos casos em que foram modelados os conectores de cisalhamento as vigas apresentaram menor rigidez e consequentemente melhor correlação entre resultados numéricos e experimentais.ABSTRACT: This paper reports a methodology adopted to represent the behavior of prestressed steel concrete composite beam by finite element models using software ABAQUS®. The methodology presents aspects related to the choice of finite elements types, mesh geometry, constitutive relations of materials, boundary conditions, steel-concrete interaction and sequence of loading.  The interaction between the concrete slab and the steel profile was carried out modeling the shear connectors, using contact elements to modeling the interface and after was carried out using TIE constraint. The validation of the numerical model was carried through the correlation between the numerical and experimental results and it was adequate to simulate the experimentally tested beams for both forms of slab profile bonding, especially for the cases where the shear connectors were modeled, because the beams presented lower stiffness and consequently greater proximity of the experimental results.

scholarly journals Experimental and Theoretical Behavior of Reinforced Concrete Two Way Slabs Strengthened by Steel Fiber Ferrocement Layers at Tension Zone

2018 ◽  
Vol 26 (3) ◽  
pp. 199-211 ◽  
Author(s):  
Mazen D. Abdullah
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Steel Fiber ◽  
Concrete Slab ◽  
Experimental Results ◽  
Wire Mesh ◽  
Reinforced Concrete Slab ◽  
Concentrated Load ◽  
Simply Supported ◽  
Reinforced Concrete Slabs

An experimental and analytical  behavior of strengthened reinforced  concrete two way slabs  by steel fiber ferrocement layers ,this  study  included  testing 14  simply supported two way slabs, which include 1 control slab, 13 strengthened slabs. In the strengthened slabs the effect of  the ferrocement layers with; steel fiber content in the ferrocement mortar  of (0.25,0.5,0.75.1.1.25%), thickness of ferrocement layers, the compressive strength for ferrocement mortar and wire mesh layers number of ferrocement was investigated. The mid span deflection at ultimate load and cracks pattern  were discussed.  All the reinforced concrete slab specimens were designed of the same dimensions and reinforced identically to fail in flexure. Simply supported conditions for all slabs has bean tested under central concentrated load. The experimental results show that; the ultimate loads and mid span deflection of strengthened reinforced  concrete slabs were more effected by  using the steel fiber on the ferrocement mortar, increasing the thickness of ferrocement and the compressive strength of ferrocement. Three-dimensional nonlinear finite element analysis has been used to conduct the analytical investigation, ANSYS (Version 16.0) computer program was used in this study. The analytical result from modeling in ANSYS program exhibited a good agreement with experimental results.

Dimension and Frequency Profiles of Concrete Highway Bridges in New Madrid Region of Southeastern Missouri

1997 ◽  
Vol 1594 (1) ◽  
pp. 84-93 ◽  
Author(s):  
Ralph Alan Dusseau
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Highway Bridges ◽  
Ambient Vibration ◽  
Earthquake Hazards ◽  
Empirical Formulas ◽  
Reinforced Concrete Slab ◽  
Box Girder ◽  
Bridge Spans ◽  
New Madrid

The results of a study funded by the U.S. Geological Survey as part of the National Earthquake Hazards Reduction Program are presented. The first objective of this study was the development of a database for all 211 highway bridges along I-55 in the New Madrid region of southeastern Missouri. Profiles for five key dimension parameters (which are stored in the database) were developed, and the results for concrete highway bridges are presented. The second objective was to perform field ambient vibration analyses on 25 typical highway bridge spans along the I-55 corridor to determine the fundamental vertical and lateral frequencies of the bridge spans measured. These 25 spans included six reinforced concrete slab spans and two reinforced concrete box-girder spans. The third objective was to use these bridge frequency results in conjunction with the dimension parameters stored in the database to develop empirical formulas for estimating bridge fundamental natural frequencies. These formulas were applied to all 211 Interstate highway bridges in southeastern Missouri. Profiles for both fundamental vertical and lateral frequencies were then developed, and the results for concrete highway bridges are presented.

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