scholarly journals Method of defining the crack formation moment in the bendable reinforced concrete components in the non-linear deformation model

2018 ◽  
Vol 456 ◽  
pp. 012038
Author(s):  
V A Eryshev
Keyword(s):  
Reinforced Concrete ◽  
Crack Formation ◽  
Deformation Model ◽  
Linear Deformation ◽  
Non Linear

scholarly journals Deformation of rockfill in bodies of rockfill dams

2019 ◽  
pp. 5-5
Author(s):  
Mikhail Sainov
Keyword(s):  
Reinforced Concrete ◽  
Deformation Modulus ◽  
Deformation Model ◽  
Observation Data ◽  
Linear Deformation ◽  
Laboratory Test Results ◽  
Wide Range ◽  
Deformation Properties ◽  
Non Linear ◽  
The Impact

Introduction. The main factor determining the stress-strain state (SSS) of rockfill dam with reinforced concrete faces is deformability of the dam body material, mostly rockfill. However, the deformation properties of rockfill have not been sufficiently studied yet for the time being due to technical complexity of the matter, Materials and methods. To determine the deformation parameters of rockfill, scientific and technical information on the results of rockfill laboratory tests in stabilometers were collected and analyzed, as well as field data on deformations in the existing rockfill dams. After that, the values of rockfill linear deformation modulus obtained in the laboratory and in the field were compared. The laboratory test results were processed and analyzed to determine the parameters of the non-linear rockfill deformation model. Results. Analyses of the field observation data demonstrates that the deformation of the rockfill in the existing dams varies in a wide range: its linear deformation modulus may vary from 30 to 500 МPа. It was found out that the results of the most rockfill tests conducted in the laboratory, as a rule, approximately correspond to the lower limit of the rockfill deformation modulus variation range in the bodies of the existing dams. This can be explained by the discrepancy in density and particle sizes of model and natural soils. Only recently, results of rockfill experimental tests were obtained which were comparable with the results of the field measurements. They demonstrate that depending on the stress state the rockfill linear deformation modulus may reach 700 МPа. The processing of the results of those experiments made it possible to determine the parameters on the non-linear model describing the deformation of rockfill in the dam body. Conclusions. The obtained data allows for enhancement of the validity of rockfill dams SSS analyses, as well as for studying of the impact of the non-linear character of the rockfill deformation on the SSS of reinforced concrete faces of rockfill dams.

scholarly journals HISTORY OF THE APPEARANCE OF EULER’S FORMULA. ISSUES OF STABILITY OF COMPRESSED REINFORCED CONCRETE ELEMENTS

2021 ◽  
Vol 11 (1) ◽  
pp. 18-25
Author(s):  
Sergey S. MORDOVSKIY ◽  
Anna A. KISELEVA
Keyword(s):  
Reinforced Concrete ◽  
High Strength Concrete ◽  
High Strength ◽  
Deformation Model ◽  
Reinforced Concrete Structures ◽  
Linear Deformation ◽  
History Of ◽  
Life Path ◽  
Concrete Elements ◽  
Concrete Hardening

The article presents a brief overview of the life path of the Swiss mathematician and mechanic Leonard Euler, considers the history of the emergence of the formula for calculating stability, shows options for taking into account the fl exibility of an element in the calculations of reinforced concrete structures, the disadvantages of the Euler curve and the features of its application in relation to structures made of high-strength concrete and concrete hardening under pressure. An example of the result of using a non-linear deformation model in the calculations of eccentrically compressed reinforced concrete elements with the introduction into the algorithm for calculating a coeffi cient that takes into account the eff ect of buckling (defl ection) of an element on its bearing capacity is given.

scholarly journals NON-LINEAR DEFORMATION AND STABILITY OF REINFORCED CONCRETE COLUMN UNDER THE LONG-TIME LOAD/GELŽBETONINĖS KOLONOS NETIESINĖS DEFORMACIJOS IR PASTOVUMAS VEIKIANT ILGALAIKEI APKROVAI

1999 ◽  
Vol 5 (3) ◽  
pp. 176-182 ◽  
Author(s):  
Igoris Cypinas
Keyword(s):  
Reinforced Concrete ◽  
Concrete Column ◽  
Reinforced Concrete Column ◽  
Linear Deformation ◽  
Non Linear ◽  
Long Time

Ankstesnėje autoriaus publikacijoje [19] paskelbtas geometriškai netiesinės gelžbetoninės konstrukcijos valkšnumo skaičiavimo skaitmeninis metodas įvertinant tempiamos betono zonos pleišėtumą laikant, kad gniuždomas betonas neišeina iš tiesinio valkšnumo ribų. Šiame straipsnyje vertinamas gniuždomo betono netiesinis valkšnumas. Taikomas sluoksniuotasis skerspjūvio modelis. Panaudotos netiesinio valkšnumo pareinamybės, kurios pateiktos Maskvos NIIŽB parengtose rekomendacijose betono valkšnumui ir susitraukimui apskaičiuoti [11]. Atsisakoma nuo valkšnumo kreivių panašumo hipotezės nepriklausomai nuo įtempimų lygio. Supleisėjusio tempiamo betono ir armatūros sąveika modeliuojama taikant išsklidusio plyšio sąvoką kai pagal (3.3) formulę sumuojamos tarp plyšių esančio betono deformacijos ir suvidurkintas plyšio atsivėrimo plotis. Konstrukcijos deformuotasis būvis modeliuojamas geometriškai ir fiziškai netiesiniais strypiniais baigtiniais elementais. Sistemos deformacijų lygtys (4.2) sprendžiamos diskretiniais laiko prieaugiais, randant deformacijų trajektoriją jungtinėje laiko ir poslinkių erdvėje. Pastovumo klausimas sprendžiamas varijuojant apkrovos dydį ir nustatant konstrukcijos egzistavimo kritinį laiko momentą, kai sistemos kitimo pobūdis tampa singuliarus. Taikomas autoriaus sukurtas netiesinis baigtinis elementas ir autoriaus sudaryta netiesinių lygčių sprendimo programa.

scholarly journals An experimental study on variability of deformation characteristics of concrete in compression

Vestnik MGSU ◽  
2020 ◽  
pp. 1390-1398
Author(s):  
Mixail G. Plyusnin ◽  
Sergey V. Tsybakin
Keyword(s):  
Experimental Study ◽  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Cross Section ◽  
Strength Analysis ◽  
Deformation Model ◽  
Deformation Characteristics ◽  
Concrete Element ◽  
Linear Deformation ◽  
Concrete Elements

Introduction. An experimental study on variability of deformation characteristics of concrete and an assessment of its influence on the bearing capacity of eccentrically compressed reinforced concrete elements were performed. In pursuance of effective regulatory documents, a non-linear deformation model was applied to perform the strength analysis of standard cross sections of reinforced concrete structures. The application of this method in probabilistic design is also of interest. Analytical functions approximating the true σ–ε diagram, made for concrete, use strength and deformation characteristics of concrete as parameters. However, variability of deformation characteristics of concrete has not been sufficiently studied, although it may have significant influence on results of analyses. Materials and methods. Complete σ–ε diagrams were made for uniaxially compressed concrete to solve this problem. These diagrams were applied to numerically assess the influence of variability of deformation characteristics of concrete on the bearing capacity of an eccentrically compressed reinforced concrete element in terms of its standard cross section. A non-linear deformation model was used to identify the bearing capacity. Results. The experiment has proven substantial variation of diagram shapes within the same strength class. The influence of the εb0 value of ultimate deformations of concrete on the bearing capacity is demonstrated for a standard cross section as a result of the strength analysis of an eccentrically compressed reinforced concrete element. The strength analysis was performed by applying experimental σ–ε diagrams made for uniaxially compressed concrete. Conclusions. The analysis of the findings has shown that the value of ultimate deformations of concrete exposed to uniaxial compression affects the bearing capacity of eccentrically compressed reinforced concrete elements. The degree of influence depends on concrete strength, reinforcement percentage and the eccentricity of a longitudinal force.

3D-DDM Simulation of Crack Propagation of Non-Linear Deformation Structural Plane

2011 ◽  
Vol 368-373 ◽  
pp. 2673-2678
Author(s):  
Ke Li ◽  
Ying Yi Wang ◽  
Xing Chun Huang
Keyword(s):  
Strength Criterion ◽  
Maximum Energy ◽  
Least Square ◽  
Displacement Discontinuity ◽  
Deformation Model ◽  
Linear Deformation ◽  
Structural Plane ◽  
Non Linear ◽  
Coulomb Criterion ◽  
Energy Release Rate Criterion

Structural plane is different from common crack, as it is often under pressure and has non-linear normal and tangential deformation behavior. This paper simulates the propagation of non-linear deformation structural plane by 3D displacement discontinuity method (DDM). Through least square regression of the elements near the tip, the stress intensity factor (SIF) of the tip is obtained. Maximum energy release rate criterion is adopted to be the fracture criterion in this paper, assuming the propagation occurred in the normal plane of the front edge, KI is modified to consider the effect of mode Ⅲ crack. The structural plane model is considered as a hyperbolic non-linear model, the Barton-Bandis model is adopted as the normal deformation model, the Kulhaway model is adopted as the tangential deformation model, and the Mohr-Coulomb criterion is adopted as the shear strength criterion. The result shows that the propagation direction is along the direction of the load, DDM could efficiently trace this process.

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