Evaluation of the Structures’ Reinforcement Effectiveness Based on Non-Linear Concrete State Diagrams

2019 ◽  
Vol 974 ◽  
pp. 491-495
Author(s):  
D.S. Toshin
Keyword(s):  
Nonlinear Deformation ◽  
Practical Calculation ◽  
Concrete Element ◽  
State Diagrams ◽  
Non Linear ◽  
Diagrammatic Method ◽  
Deformation Diagrams

The article describes a diagrammatic method for evaluating the effectiveness of strengthening structures under load. As an indicator of efficiency, a parameter is introduced that is set as the level of reinforcement loading of concrete by the beginning of the reinforced structure’s concrete destruction. The nonlinear deformation diagrams show the sequence of development and redistribution of stresses in the sections of the conditional inflexible concrete element, amplified without removing the load. The results of the practical calculation of the gain under load for some variations of the strength and the deformative characteristics of concrete are given. The data obtained indicate the possibility of applying the proposed methodology to the evaluation of the strengthening structures effectiveness without removing the load.

Improving the Methodology for Calculating the Bearing Capacity of Eccentrically Compressed Reinforced Concrete Elements Based on the Use of the Refined Curvilinear Deformation Diagrams of Concrete and Reinforcement

2019 ◽  
Vol 974 ◽  
pp. 570-576
Author(s):  
Alexander I. Nikulin ◽  
Al-Khawaf Ali Fadhil Qasim
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Linear Equations ◽  
Resistance Force ◽  
Deformation Model ◽  
Concrete Element ◽  
Element Determination ◽  
Numerical Studies ◽  
Concrete Elements ◽  
Deformation Diagrams

The article proposes a new approach to improving the methodology for calculating the bearing capacity of the eccentrically compressed reinforced concrete elements for cases of their loading with large eccentricities. The basis of this technique is considered as a modified version of the deformation model for the reinforced concrete resistance force. The main feature of this model is the energy approach to transforming the reference diagrams of compression and concrete tension into the diagrams of non-uniform deformation, corresponding to the stress-strain state of the compressed and stretched zones of concrete in the cross section of the eccentrically compressed reinforced concrete structures. This way there is no falling branch in the concrete diagrams obtained by this method. A calculation diagram of the steel reinforcement deformation with a physical yield point was taken as a partial function, consisting of one linear and two non-linear equations. The proposed method also shows the possibility of taking into account the greatest curvature of an eccentrically compressed reinforced concrete element in the plane of its loading. The article presents all the necessary dependencies allowing the theoretical value of the carrying capacity of an eccentrically compressed reinforced concrete element determination. The results of the numerical studies performed using the design software developed by the authors for the personal computer are given.

scholarly journals CONSTRUCTION OF DEFORMATION DIAGRAMS OF CONCRETE UNDER SHEAR BASED ON THE AUTHOR'S THEORY OF ANISOTROPIC MATERIALS POWER RESISTANCE TO COMPRESSION AND DEFORMATION THEORY OF PLASTICITY

2019 ◽  
Vol 15 (3) ◽  
pp. 149-160 ◽  
Author(s):  
Boris Sokolov ◽  
Oleg Radaikin
Keyword(s):  
Deformation Theory ◽  
Strain State ◽  
Pure Shear ◽  
Anisotropic Materials ◽  
Normal Stresses ◽  
State Diagrams ◽  
Theory Of Plasticity ◽  
Tension And Compression ◽  
Concrete Elements ◽  
Deformation Diagrams

The Aim of this work was the construction of a concrete deformation diagrams under shear on the basis of two approaches: the theory of anisotropic materials force resistance in compression and deformation theory of plasticity with the use of state diagrams of concrete under tension and compression, obtained by the authors jointly with Acad. N.I. Karpenko earlier. For this purpose, in the framework of the first approach, the main computational expression of the author's model was written in the current deformations, which ultimately allowed to establish a relationship between the diagrams σb-εb, σbt-εbt and τb-γb and reveal the mechanics of destruction of concrete elements under compression. The second approach additionally takes into account the change in the coefficient of transverse deformations, µb, and shear modulus of deformations, Gb as the load increases, but does not take into account the presence of normal stresses affecting the stress-strain state. This approach recreates the conditions of pure shear, which is possible only theoretically, and in real designs is applicable with a certain degree of error. Nevertheless, both approaches provide almost identical data in the construction of diagrams «τb-γb», which differ from the experiment by no more than 13-15%. In this regard, they are recommended for implementation: the first-to perform engineering calculations «manually», the second-to develop computer programs that allow you to automate the calculation.

scholarly journals NON-LINEAR 3D MODELLING OF RC SLAB PUNCHING SHEAR FAILURE

2004 ◽  
Vol 10 (4) ◽  
pp. 311-316
Author(s):  
Povilas Vainiunas ◽  
Vladimiras Popovas ◽  
Andrej Jarmolajev
Keyword(s):  
Reinforced Concrete ◽  
Numerical Analysis ◽  
Shear Failure ◽  
Computer Modelling ◽  
Practical Calculation ◽  
Floor Slab ◽  
Concrete Floor ◽  
Reinforced Concrete Slabs ◽  
Non Linear ◽  
Rc Slab

Modern technologies of 3D computer modelling with the help of finite‐element methods of numerical analysis in non‐linear aproach enable a reliable simulation of real reinforced concrete slabs behaviour under the conditions of complicated stress‐strain state in all the stages of their behaviour under loading, including a stage of elasticity‐plasticity state in concrete and reinforcement as well as formation and development of destruction mechanism. Numerical methods of modelling of critical behaviour of structures go beyond the borders of scientific research, being increasingly applied for solving non‐trivial engineering tasks when it becomes evident that possibilities of analytical approach, acceptable for the existing design codes are not sufficient. In such a case an exceptional attention is to be paid for verification of calculated models against experimental research of similar numeric models. This article reviews a case of complex experimental‐theoretical and numerical calculation and analysis methods applied for a reinforced concrete floor slab and column connection. The object of research is of exceptional interest as for practical calculation methods for this type of constructions following design norms of different countries revision and additional processing are necessary. The results of the reinforced concrete floor slab and column junction computer model non‐linear numerical analysis are presented and compared with the results of an experimental study.

B. The Non-Linear Calculations for Pulsating Stars

1967 ◽  
Vol 28 ◽  
pp. 105-176
Author(s):  
Robert F. Christy
Keyword(s):  
Major Part ◽  
Afternoon Session ◽  
Discussion Session ◽  
Pulsating Stars ◽  
Fourth Symposium ◽  
Non Linear ◽  
Considerable Discussion ◽  
Informal Approach ◽  
Preceding Session

(Ed. note: The custom in these Symposia has been to have a summary-introductory presentation which lasts about 1 to 1.5 hours, during which discussion from the floor is minor and usually directed at technical clarification. The remainder of the session is then devoted to discussion of the whole subject, oriented around the summary-introduction. The preceding session, I-A, at Nice, followed this pattern. Christy suggested that we might experiment in his presentation with a much more informal approach, allowing considerable discussion of the points raised in the summary-introduction during its presentation, with perhaps the entire morning spent in this way, reserving the afternoon session for discussion only. At Varenna, in the Fourth Symposium, several of the summaryintroductory papers presented from the astronomical viewpoint had been so full of concepts unfamiliar to a number of the aerodynamicists-physicists present, that a major part of the following discussion session had been devoted to simply clarifying concepts and then repeating a considerable amount of what had been summarized. So, always looking for alternatives which help to increase the understanding between the different disciplines by introducing clarification of concept as expeditiously as possible, we tried Christy's suggestion. Thus you will find the pattern of the following different from that in session I-A. I am much indebted to Christy for extensive collaboration in editing the resulting combined presentation and discussion. As always, however, I have taken upon myself the responsibility for the final editing, and so all shortcomings are on my head.)

A decomposition method in non-linear programmm

Optimization ◽  
1975 ◽  
Vol 6 (4) ◽  
pp. 549-559
Author(s):  
L. Gerencsér
Keyword(s):  
Decomposition Method ◽  
Non Linear
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