Download or read book Finite Element Prediction of Punching Shear Failure of Axisymmetric Reinforced Concrete Slabs written by Tao Xuekang and published by . This book was released on 1984 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nonlinear Finite Element Analysis of Punching Shear of Reinforced Concrete Slab column Connections written by Aikaterini Genikomsou and published by . This book was released on 2016 with total page 237 pages. Available in PDF, EPUB and Kindle. Book excerpt: The code provisions for the design of reinforced concrete slabs are based on empirical and mostly statistical formulations derived from the tests. The available testing database consists of different types of slabs and in some cases it is limited due to the extensive cost and time that a punching shear test requires. Thus, there is a need for verification of the actual code provisions and this can be done in part by using finite element (FE) simulations. The finite element analyses (FEA) can supplement the existing testing background and can be used for parametric investigation, since they can indicate different aspects on punching shear failure, leading to possible recommendations for the design codes and models. In this thesis, 3D FEA of reinforced concrete slabs with the FE software ABAQUS using the concrete damaged plasticity model are presented. The appropriate calibration of the concrete model, is done in this study based on an interior slab-column connection without shear reinforcement (SB1), considered as the control specimen, which was tested under vertical loading in a previous study. The predictive capability of the calibrated model was demonstrated by simulating and analyzing different types of slabs without shear reinforcement. Interior specimens under static and reversed cyclic loadings and edge slabs under static and horizontal loadings are examined. The predicted capability of the calibrated model is then examined by simulating slab-column connections with shear reinforcement. Four different modelling approaches for the shear bolts are presented. Discussion and comparison between the design codes are also presented. A parametric study based on the different shear reinforcement patterns that ACI code (rectangular) and EC2 (radial) propose is conducted. This study also involves the investigation of the effect of openings on the punching shear behaviour of the reinforced concrete slabs without shear reinforcement. The effect of the location, the distance from the column and the size of the opening on the punching shear resistance, are investigated. The results, confirm that the punching shear resistance is decreased with an increase in the opening size and with a decrease in the opening distance from the column. Finally, the compressive membrane action effect on reinforced concrete slabs is examined. FEA are performed considering an isolated interior flat slab (SB1) as continuous. The predictive capability of the FEA models enhance their effectiveness for further investigation on the effect of membrane action by supplementing the limited testing background in this area.

Download or read book Punching of Structural Concrete Slabs written by fib Fédération internationale du béton and published by fib Fédération internationale du béton. This book was released on 2001-01-01 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: Punching is considered to be one of the most difficult problems in structural concrete design and mechanical models or theoretical analyses were developed rather late in the history of concrete research attempts. This fib Bulletin reviews the development of design models and theoretical analyses since the CEB Bulletin 168 Punching Shear in Reinforced Concrete - State-of-the-Art Report published in 1985. The role of the concrete tensile strength was specially addressed. In this respect the present bulletin is also following-up the CEB Bulletin 237 Concrete Tension and Size Effects - Utilisation of concrete tension in structural concrete design and relevance of size effect - Contributions from CEB Task Group 2.7 published in 1997. Apart from new theoretical developments a comprehensive databank for comparisons with experimental evidence is included. About 400 punching tests were critically reviewed and evaluated in a consistent manner. This is thought to be the first step towards a generally agreed selection of reliable tests. The evident value of such a data bank is illustrated by comparisons carried out between the data and some of the analytical proposals as well as empirical code formulas. List of contents : (1) Introduction, (2) Code equations, (3) Mechanical models for punching, (4) New developments for mechanical models, (5) Numerical investigations, (7) Comparison of mechanical models and test results of slabs without shear reinforcement, (8) Comparison of code rules and tests of flat slabs without shear reinforcement, (9) Comparison of codes, models and tests of flat slabs with shear reinforcement, (10) Experimental investigations, (11) Summary and conclusions, References, Appendices : (I) Databank on slabs without shear reinforcement, (II) Databank on slabs with shear reinforcement, (III) Comparison of test data with code rules, (IV) Comparison of test data with selected models, (V) Notations.

Download or read book Finite Element Analysis of Reinforced Concrete and Steel Fiber Reinforced Concrete Slabs in Punching Shear written by Todd Puddicome and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Punching shear capacity of reinforced concrete slabs is influenced by the following material properties: concrete compressive strength, flexural reinforcement ratio, inclusion of steel fibers in the concrete mix, and the reinforcing steel yield strength. A review of current finite element analysis models reveals that a unified approach to include all of these variables into one coherent model does not exist. This thesis presents a finite element model capable of making accurate predictions on the ultimate punching shear load and load - deflection response of a reinforced concrete slab. The model simulates the nonlinear constitutive properties of reinforced concrete by proposing a robust model to represent the behavior through the Concrete Damaged Plasticity (CDP) constitutive model. The thesis defines the parameters for the CDP model in a finite element analysis and develops an expression to mitigate mesh size dependency. A tension - stiffening model is proposed using an exponential decay expression with variables to account for varying concrete compressive strength, flexural reinforcement ratio, inclusion of steel fibers in the concrete mix, and the reinforcing steel yield strength. The model is calibrated using a series of experimental data from the literature and validated by successfully replicating the punching shear behavior of experimental specimens data from the literature.

Download or read book Punching shear of structural concrete slabs written by FIB - Féd. Int. du Béton and published by FIB - Féd. Int. du Béton. This book was released on 2017 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt: fib Bulletin 81 reports the latest information available to researchers and practitioners on the analysis, design and experimental evidence of punching shear of structural concrete slabs. It follows previous efforts by the International Federation for Structural Concrete (fib) and its predecessor the Euro-International Committee for Concrete (CEB), through CEB Bulletin 168, Punching Shear in Reinforced Concrete (1985) and fibBulletin 12, Punching of structural concrete slabs (2001), and an international symposium sponsored by the punching shear subcommittee of ACI Committee 445 (Shear and Torsion) and held in Kansas City, Mo., USA, in 2005. This bulletin contains 18 papers that were presented in three sessions as part of an international symposium held in Philadelphia, Pa., USA, on October 25, 2016. The symposium was co-organized by the punching shear sub-committee of ACI 445 and by fib Working Party 2.2.3 (Punching and Shear in Slabs) with the objectives of not only disseminating information on this important design subject but also promoting harmonization among the various design theories and treatment of key aspects of punching shear design. The papers are organized in the same order they were presented in the symposium. The symposium honored Professor Emeritus Neil M. Hawkins (University of Illinois at Urbana-Champaign, USA), whose contributions through the years in the field of punching shear of structural concrete slabs have been paramount. The papers cover key aspects related to punching shear of structural concrete slabs under different loading conditions, the study of size effect on punching capacity of slabs, the effect of slab reinforcement ratio on the response and failure mode of slabs, without and with shear reinforcement, and its implications for the design and formulation in codes of practice, an examination of different analytical tools to predict the punching shear response of slabs, the study of the post-punching response of concrete slabs, the evaluation of design provisions in modern codes based on recent experimental evidence and new punching shear theories, and an overview of the combined efforts undertaken jointly by ACI 445 and fib WP 2.2.3 to generate test result databanks for the evaluation and calibration of punching shear design recommendations in North American and international codes of practice.

Download or read book An Experimental Study and Finite Element Analysis of Punching Shear Failure in Steel fibre reinforced Concrete Ground suspended Floor Slabs written by Wafa Abdelmajeed Labib and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nonlinear Finite Element Analysis of Punching Shear of Reinforced Concrete Slabs Supported on Rectangular Columns written by Graeme Jacob Milligan and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Historical and current design code provisions for the punching shear of reinforced concrete slabs supported on rectangular columns vary greatly and are primarily based on empirical results. Additionally, the existing database for slabs supported on rectangular columns is quite small compared to the empirical database for reinforced concrete slabs supported on square columns. Conducting experimental tests of slabs supported on rectangular columns can be quite expensive and time consuming due to the required specimen size. As such, properly calibrated finite element simulations can be useful to expand the existing database and verify the accuracy of code provisions. In this thesis a three-dimensional nonlinear finite element analysis (FEA) of interior slab-column connections subjected to concentric vertical loading, in the commercial FEA software ABAQUS, is presented. The finite element model was calibrated following the calibration procedure described in Genikomsou (2015), which was focused on the FEA of punching shear of slabs supported on square columns. Slab AM04, which was a slab tested by Sagaseta et al. (2014), and which represents an interior slab-column connection with a column rectangularity (aspect ratio) of three is considered as the control specimen in the calibration. The calibration was then verified by modelling the three remaining slabs in the AM series and three additional slabs tested by Sagaseta et al. (2011). These additional slabs were supported on square columns and had different concrete strengths and flexural reinforcing ratios than the AM series slabs. The calibrated finite element model (FEM) was found to be able to accurately predict the load deflection response and crack patterns of the tested slabs. The calibrated FEM was then used to conduct a parametric study on the impact of column rectangularity on the punching shear behaviour of interior slab-column connections. Based on a comparison of current and historical code provisions two parameters, the column aspect ratio, and the ratio of the length of the minimum column dimension, cmin, to the effective flexural depth of the slab, d, were considered in the parametric study. In total 77 simulations spanning 8 cmin/d ratios were conducted. The results of these 77 simulations demonstrated that the impact of column rectangularity is not independent of the cmin/d ratio. As the cmin/d ratio increased the impact of column rectangularity predicted by the FEM, Eurocode 2 (2004), Model Code 2010 and the Critical Shear Crack Theory (CSCT) became more severe. Predictions according to ACI318M-14 were nearly independent of the ratio of cmin/d and were typically unconservative compared to the FEM results for cmin/d ratios greater than approximately 1.3. Additionally, the FEM, Eurocode 2 (2004), Model Code 2010 and the CSCT predicted an impact of rectangularity for column aspect ratios between 1 and 2, which differs from the current ACI 318 provisions. The shear stress distributions in the slab along the support perimeter were also analyzed. Shear stresses were found to concentrate near the corner of the supported area and along the short side of the supported area. As the cmin/d ratio increased these concentrations became more focused at the column corner.

Download or read book Characterization of the Punching Shear Capacity of Thin Ultra high Performance Concrete Slabs written by Devin K. Harris and published by . This book was released on 2005 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ultra-high performance concrete (UHPC) is a relatively new type of concrete that exhibits mechanical properties that are far superior to those of conventional concrete and in some cases rival those of steel. The main characteristics that distinguish UHPC from conventional reinforced concrete are its very high compressive strength (20 to 33 ksi), the addition of steel fibers which enables tension to be carried across open cracks without conventional reinforcing steel, and a very high resistance to corrosion and degradation. The mechanical properties of UHPC allow for smaller, thinner sections as compared to conventional reinforced concrete sections. However, as it is a new material, the use of UHPC has been limited to a few structural applications due primarily to the high cost of the material and the lack of established design guidelines. In previous research, a material model based on physical tests was used in conjunction with finite element models to develop an optimized cross-section for a prestressed UHPC girder for bridge applications. The cross-section is a double-tee with bulbs at the bottoms of the webs to accommodate the prestressing strands. As it is envisioned in bridge applications, the double-tees will be placed directly adjacent to one another, and the top flange will act as the riding surface after a thin asphalt overlay is placed. Based on the longitudinal compressive stresses, the top flange of the girder can be quite thin. However, there exists the possibility that a punching shear failure could occur from the application of a point load such as a wheel patch load if the flange is made too thin. The research reported herein was initiated to characterize the punching shear capacity of thin UHPC plates and to develop recommendations on the minimum top flange thickness for the optimized double-tee. Twelve small slabs (45 in x 45 in) were tested to failure to characterize the punching shear strength of UHPC. The variables considered were the slab thickness (2, 2.5, and 3 in) and loading plate dimensions (from 1 in x 1 in to 3 in x 3 in). The results of the testing were compared to several existing models for punching shear. The two equations that predicted strengths most reliably were the current ACI punching shear equation and a modified bolt pull-out equation. After evaluation of the test results, the minimum slab thickness required to prevent a punching shear failure in the top flange due to an 8 in x 20 in wheel patch was determined to be 1 in. Three larger slabs were also tested. These slabs had the same clear span length as the top flange of the optimized double-tee and were loaded with a wheel patch load. The slabs were all approximately 3 in thick and all failed in flexure rather than punching shear. It was concluded that the casting method has a strong influence on the orientation of the steel fibers, which in turn influences the flexural strength in orthogonal directions in the slab. The top flange thickness will be governed by transverse bending rather than punching shear, and the 3 in slabs were not able to support the full wheel load plus impact and load factor. The results of this research help in the continued optimization of a UHPC shape for use in highway bridges. If material use in the girder is minimized, UHPC bridges can become economically competitive with HPC bridges, but offer the benefits of more rapid construction and better durability.

Download or read book Selected Papers from Chinese Journals of Structural Engineering written by Robert C. Y. Young and published by . This book was released on 1989 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: Of the twenty papers included in this volume (selected from two Chinese journals published in 1985 and 1986), four are related to bridge structures and the other sixteen to buildings design aspects, effects of earthquakes, computational methodology for complex structural analysis. No index. Annotation copyright Book News, Inc. Portland, Or.

Download or read book Finite Element Analysis of Prestressed Concrete Structures Using Post Tensioning Steel written by Yu Huang and published by Cambridge Scholars Publishing. This book was released on 2020-05-28 with total page 305 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book details the theory and applications of finite element (FE) modeling of post-tensioned (PT) concrete structures, and provides the updated MATLAB code (as of 2019). The challenge of modeling PT prestressed concrete structures lies in the treatment of the interface between the concrete and prestressing tendons. Using MATLAB, this study develops an innovative nonlinear FE formulation which incorporates contact techniques and engineering elements to considerably reduce the need of computational power. This FE formulation has the ability to simulate different PT frame systems with fully bonded, fully unbonded or partially bonded tendons, as well as actual sliding behavior and frictional effects in the tendons. It also allows for the accurate simulation of anchor seating loss.

Download or read book Structural Analysis and Design of Reinforced Concrete Slabs on Grade written by Mohamed Nasser Ahmed Nader Darwish and published by . This book was released on 1988 with total page 812 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Finite Element Modeling of Punching Shear Behavior of Ultra High Performance Fiber Reinforced Concrete Slabs Considering Effect of Fiber Orientation written by Thuc Nhu Nguyen and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The present study represents a numerical study on the punching shear behavior of ultra-high performance steel fiber reinforced concrete (UHPFRC) slabs without shear reinforcement, particularly considering the effect of fiber orientation, validated by experimental results. In recent decades, ultra-high performance steel fiber reinforced concrete (UHPFRC) has been a new achievement in concrete technology. Due to its superior mechanical properties, civil engineers can address the problem of punching shear of thin slabs that are currently widely used in buildings. By processing some studies, researchers have found that the strength capacity of the material before cracking and the post-cracking resistance strongly depend on the orientation of the fibers, which heavily rely on the casting direction and casting method. While most of previous studies focused on the effect on the behavior of beams, the present research particularly considers how the casting procedures as well as the volume content of the fiber affect the punching shear behavior of flat slabs.Based on models from the previous research and this research’s experimental results, constitutive model of material was proposed to capture the effects of fiber orientation. Different parts of the slab according to different distances from casting positions produce different fiber orientations, and lead to different material models, particularly tensile constitutive models. The material models were applied to finite element analysis in ABAQUS/Explicit, using Concrete Damage Plasticity model to simulate the punching shear behavior of the flat slabs. The appropriation of proposed material models and finite element modeling procedure were validated by comparing to experimental results. Consequently, these models can be used further to consider the effect of fiber orientation in future researches and utilizations of UHPFRC structures.

Download or read book Finite Element Prediction of Reinforced Concrete Behavior written by Subramaniam Balakrishnan and published by . This book was released on 1986 with total page 487 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Finite Element Analysis of Punching Shear Strength of Reinforced Concrete Structures written by Moujalli C. Hourani and published by . This book was released on 1988 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Investigation Into Punching Strength of Reinforced Concrete Slabs Using Finite Element Analysis written by Peter Ochota and published by . This book was released on 1971 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Punching Shear in Reinforced Concrete Slabs written by Maria Anna Polak and published by . This book was released on 2005 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Finite Element Analysis of Reinforced Concrete Structures 2003 written by Laura N. Lowes and published by . This book was released on 2006 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt: