Implementation of smeared crack approach in rigid block and spring modeling of reinforced concrete

2019 ◽  
Vol 201 ◽  
pp. 109779 ◽  
Author(s):  
Saeed Moshirabadi ◽  
Masoud Soltani
Keyword(s):  
Reinforced Concrete ◽  
Rigid Block ◽  
Smeared Crack Approach ◽  
Smeared Crack

SHRINKAGE IN REINFORCED CONCRETE STRUCTURES: A COMPUTATIONAL ASPECT/BETONO TRAUKIMOSI ĮTAKA GELŽBETONINIŲ ELEMENTŲ ELGSENAI: SKAIČIAVIMO YPATUMAI

2008 ◽  
Vol 14 (1) ◽  
pp. 49-60 ◽  
Author(s):  
Viktor Gribniak ◽  
Gintaris Kaklauskas ◽  
Darius Bacinskas
Keyword(s):  
Reinforced Concrete ◽  
Test Data ◽  
Prediction Models ◽  
Shrinkage Strain ◽  
Reinforced Concrete Beams ◽  
Computational Aspect ◽  
Concrete Members ◽  
Calculation Technique ◽  
Smeared Crack Approach ◽  
Smeared Crack

This paper introduces the recent state of research on shrinkage of concrete. It reviews prediction models of shrinkage strain and curvature analysis methods of reinforced concrete members. New test data on concrete shrinkage has been presented. Various factors that influence shrinkage have been discussed. A calculation technique on short‐term deformations of cracked reinforced concrete members including shrinkage has been introduced. The technique is based on layer model and smeared crack approach. Shrinkage influence on behaviour of reinforced concrete beams was investigated numerically and compared with test data reported in the literature. It has been shown that shrinkage has significantly reduced the cracking resistance and leads to larger deflections. Santrauka Straipsnyje atlikta betono traukimosi įtakos gelžbetoninių elementų elgsenai analizė, pateikta betono traukimosi deformacijų apskaičiavimo modelių apžvalga, aptarti traukimosi sukeltų kreivių nesimetriškai armuotuose gelžbetoniniuose elementuose apskaičiavimo metodai, taip pat pateikti nauji betono traukimosi eksperimentinių tyrimų duomenys. Aptarti veiksniai, turintys įtaką traukimosi deformacijoms, aprašytas supleišėjusių gelžbetoninių elementų trumpalaikių deformacijų apskaičiavimo algoritmas, rodantis traukimosi įtaką. Algoritmas pagrįstas sluoksnių modeliu ir vidutinių deformacijų koncepcija. Traukimosi įtaka gelžbetoninių sijų elgsenai nagrinėta, taikant normų bei sluoksnių metodus. Teoriniai rezultatai palyginti su literatūroje paskelbtais eksperimentinių tyrimų rezultatais. Parodyta, kad betono traukimasis gerokai sumažina trumpalaike apkrova veikiamų gelžbetoninių sijų atsparumą pleišėjimui bei lemia didesnes įlinkių reikšmes.

scholarly journals METHODS AND CONSTITUTIVE MODELS FOR DEFORMATIONAL ANALYSIS OF FLEXURAL REINFORCED CONCRETE MEMBERS/LENKIAMŲJŲ GELŽBETONINIŲ ELEMENTŲ DEFORMATYVUMO VERTINIMO METODAI IR FIZIKINIAI MODELIAI

2000 ◽  
Vol 6 (5) ◽  
pp. 329-338
Author(s):  
Gintaris Kaklauskas
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Reinforced Concrete ◽  
Constitutive Model ◽  
Critical Survey ◽  
Stress Strain ◽  
Constitutive Relationships ◽  
Concrete Members ◽  
Smeared Crack Approach ◽  
Smeared Crack

The paper reviews both analytical and finite element methods for deformational analysis of flexural reinforced concrete members subjected to short-term loading. In a state-of-the-art summary of various proposed stress-strain relationships for concrete and reinforcement, a special emphasis is made on critical survey of modelling post-cracking behaviour of tensile concrete in smeared crack approach. Empirical code methods of different countries (American Code (ACI Committee 318 [7]), the Eurocode EC2 [8], and the Russian (old Soviet) Code (SNiP 2.03.01-84 [5]) for deflection calculation of flexural reinforced concrete members are briefly described in section 2. Although these methods are based on different analytical approaches, all of them proved to be accurate tools for deflection assessment of members with high and average reinforcement ratios. It should be noted that these methods have quite a different level of complexity since the Russian Code method employs a great number of parameters and expressions whereas the ACI and EC2 methods are simple and include only basic parameters. Approaches of numerical simulation and constitutive relationships are discussed in Chapter 3. All numerical simulation research can be classified into two large groups according to two different approaches for crack modelling (subsection 3.1): 1) Discrete cracking model. In this approach, cracks are traced individually as they progressively alter the topology of the structure. 2) Smeared cracking model. The cracked concrete is assumed to remain a continuum, ie the cracks are smeared out in the continuous fashion. After cracking, the concrete becomes orthotropic with one of the material axes being oriented along the direction of cracking. Constitutive relationships for steel and plain concrete are presented in subsection 3.2. A special emphasis is made on critical survey of modelling post-cracking behaviour of tensile concrete in smeared crack approach. It has been concluded that although empirical design codes of different countries ensure safe design, they do not reveal the actual stress-strain state of cracked structures and often lack physical interpretation. Numerical methods which were rapidly progressing within last three decades are based on universal principles and can include all possible effects such as material nonlinearities, concrete cracking, creep and shrinkage, reinforcement slip, etc. However, the progress is mostly related to the development of mathematical apparatus, but not material models or, in other words, the development was rather qualitative than quantitative. Constitutive relationships often are too simplified and do not reflect complex multi-factor nature of the material. Existing constitutive relationships for concrete in tension do not assure higher statistical accuracy of deflection estimates for flexural reinforced concrete members in comparison to those obtained by empirical code methods. The author has developed integral constitutive model for deformational analysis of flexural reinforced concrete members [36]. The integral constitutive model consists of traditional constitutive relationships for reinforcement and compressive concrete and the integral constitutive relationship for cracked tensile concrete which accumulates cracking, tension stiffening, reinforcement slippage and shrinkage effects. This constitutive model can be applied not only in a finite element analysis, but also in a simple iterative technique based on classical principles of strength of materials extended to layered approach.

scholarly journals Reinforced Concrete Finite Element Analysis Incorporating Material Nonlinearity and Failure Criteria Aspects

2013 ◽  
Vol 284-287 ◽  
pp. 1230-1234 ◽  
Author(s):  
Tud Jono Sri ◽  
Aylie Han ◽  
Lie Hendri Hariwijaya
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Failure Criteria ◽  
Matrix Formulation ◽  
Element Analysis ◽  
Linear Behavior ◽  
Highly Nonlinear ◽  
Smeared Crack Approach ◽  
Smeared Crack ◽  
Cracking Pattern

The behavior of concrete is highly nonlinear, even at very low loading levels. Steel, on the other hand, exhibits a relatively linear behavior up till yielding. The synergy between the two materials and their compatibility has long been the subject of research. While the failure criterion for steel is straight forward, concrete can be approached by various theories. The most prominent are the Kupfer-Hilsdorf-Rusch and the Möhr failure envelope. The behavior of material under bi-axial stresses subsequent to cracking can be assumed isotropic or orthotropic, resulting in a differentiation in the material constitutive matrix formulation. This work covers the finite element modeling of reinforced concrete elements, based on the two failure envelopes, while assessing the isotropic and orthotropic methodology. The Finite Element smeared crack approach is used to analyze stresses and the propagation of cracking pattern for the element. The resulting load – displacement curves are validated with identical laboratory tested specimens.

Finite element modelling of plain and reinforced concrete specimens with the Kotsovos and Pavlovic material model, smeared crack approach and fine meshes

2021 ◽  
pp. 105678952098660
Author(s):  
George Markou ◽  
Wynand Roeloffze
Keyword(s):  
Reinforced Concrete ◽  
Numerical Models ◽  
Research Work ◽  
Plain Concrete ◽  
Material Model ◽  
Ultimate Limit State ◽  
Material Models ◽  
Concrete Material ◽  
Smeared Crack Approach ◽  
Smeared Crack

Modelling of concrete through 3 D constitutive material models is a challenging subject due to the numerous nonlinearities that occur during the monotonic and cyclic analysis of reinforced concrete structures. Additionally, the ultimate limit state modelling of plain concrete can lead to numerical instabilities given the lack of steel rebars that usually provide with the required tensile strength inducing numerical stability that is required during the nonlinear solution procedure. One of the commonly used 3 D concrete material models is that of the Kotsovos and Pavlovic, which until recently it was believed that when integrated with the smeared crack approach, it can only be used in combination with relatively larger in size finite elements. The objective of this study is to investigate into this misconception by developing different numerical models that foresee the use of fine meshes to simulate plain concrete and reinforced concrete specimens. For the needs of this research work, additional experiments were performed on cylindrical high strength concrete specimens that were used for additional validation purposes, whereas results on a reinforced concrete beam found in the international literature were used as well. A discussion on the numerical findings will be presented herein by comparing the different experimental data with the numerically predicted mechanical response of the under study concrete material model.

scholarly journals Calibrating a New Constitutive Tension Model to Extract a Simplified Nonlinear Sectional Analysis of Reinforced Concrete Beams

2021 ◽  
Vol 11 (5) ◽  
pp. 2292
Author(s):  
Alaaeldin Abouelleil ◽  
Hayder A. Rasheed
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Compressive Strain ◽  
Design Criterion ◽  
Reinforced Concrete Beams ◽  
Secondary Outcome ◽  
Shear Stresses ◽  
Structural Members ◽  
Flexural Member ◽  
Smeared Crack

Nonlinear analysis of structural members is vital to understand the behavior and the response of reinforced concrete members. Even though most design procedures concentrate on the ultimate stage of response towards the end of the post-yielding zone as the decisive design criterion, the structural members usually function at the service load levels within the post-cracking zone. Therefore, cracking is a critical aspect of concrete behavior that affects the overall response of reinforced concrete beams. The initiation and the propagation of the cracks are affected directly by the tension and shear stresses in the beam. In flexural beams, the tensile stresses dominate the crack onset and its growth. Cracks in reinforced concrete flexural beams leave non-cracked regions in between the cracked sections. In order to apply a consistent analysis strategy, the smeared crack approach averages the behavior of these different cracked sections and uncracked in between regions to generate an accurate global response of the entire beam. This study presents a numerical constitutive tensile model that captures the complete tensile response of the reinforced concrete flexural member, in terms of averaged/smeared crack response. As a second step, this model was examined against a large pool of experimental data to validate its accuracy. Overall, the main objective of this study is to develop a representative constitutive tensile model for reinforced concrete flexural members and validate its accuracy against experimental results. The full nonlinear sectional response is analytically realized, based on the assumed trilinear moment–curvature response and the assumed trilinear moment–extreme fiber compressive strain response. This is considered as the secondary outcome of the present study.

scholarly journals Effects of Nonuniform Fiber Geometries on the Microstructural Fracture Behavior of Ceramic Matrix Composites

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Hye-gyu Kim ◽  
Wooseok Ji ◽  
Nam Choon Cho ◽  
Jong Kyoo Park
Keyword(s):  
Optimization Algorithm ◽  
Fracture Behavior ◽  
Ceramic Matrix Composite ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Shear Loading ◽  
Matrix Composites ◽  
Specific Loading ◽  
Smeared Crack Approach ◽  
Smeared Crack

Microstructural fracture behavior of a ceramic matrix composite (CMC) with nonuniformly distributed fibers is studied in the presentation. A comprehensive numerical analysis package to study the effect of nonuniform fiber dimensions and locations on the microstructural fracture behavior is developed. The package starts with an optimization algorithm for generating representative volume element (RVE) models that are statistically equivalent to experimental measurements. Experimentally measured statistical data are used as constraints while the optimization algorithm is running. Virtual springs are utilized between any adjacent fibers to nonuniformly distribute the coated fibers in the RVE model. The virtual spring with the optimization algorithm can efficiently generate multiple RVEs that are statistically identical to each other. Smeared crack approach (SCA) is implemented to consider the fracture behavior of the CMC material in a mesh-objective manner. The RVEs are subjected to tension as well as the shear loading conditions. SCA is capable of predicting different fracture patterns, uniquely defined by not only the fiber arrangement but also the specific loading type. In addition, global stress-strain curves show that the microstructural fracture behavior of the RVEs is highly dependent on the fiber distributions.

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