scholarly journals Credibility of Design Procedures

10.14311/266 ◽  
2001 ◽  
Vol 41 (4-5) ◽  
Author(s):  
J. Marková ◽  
M. Holický
Keyword(s):  
Structural Reliability ◽  
Concrete Slab ◽  
Theoretical Models ◽  
Comprehensive Analysis ◽  
Structural Elements ◽  
Structural Element ◽  
Limit States ◽  
Reinforced Concrete Slab ◽  
Design Procedures ◽  
Design Value

Theory of structural reliability enables comprehensive analysis of structural elements with respect to various limit states, and provides valuable insights into the methodology of applied standards. In addition to reliability analysis of the structural element, a new concept of the credibility of theoretical models used to calculate the design value of basic variables is introduced. The presented example of structural verification for limit states of cracking shows that the credibility of commonly applied formulas and reliability of a reinforced concrete slab have a great scatter and are in some cases inadequate.

STRUCTURAL RELIABILITY ANALYSIS BASED ON P-BOXES

2020 ◽  
Vol 92 (6) ◽  
pp. 51-58
Author(s):  
S.A. SOLOVYEV ◽  
Keyword(s):  
Probability Distribution ◽  
Reliability Analysis ◽  
Structural Reliability ◽  
Epistemic Uncertainty ◽  
Random Variable ◽  
Strength Criterion ◽  
Structural Elements ◽  
Structural Element ◽  
Limit States ◽  
Distribution Shape

The article describes a method for reliability (probability of non-failure) analysis of structural elements based on p-boxes. An algorithm for constructing two p-blocks is shown. First p-box is used in the absence of information about the probability distribution shape of a random variable. Second p-box is used for a certain probability distribution function but with inaccurate (interval) function parameters. The algorithm for reliability analysis is presented on a numerical example of the reliability analysis for a flexural wooden beam by wood strength criterion. The result of the reliability analysis is an interval of the non-failure probability boundaries. Recommendations are given for narrowing the reliability boundaries which can reduce epistemic uncertainty. On the basis of the proposed approach, particular methods for reliability analysis for any structural elements can be developed. Design equations are given for a comprehensive assessment of the structural element reliability as a system taking into account all the criteria of limit states.

scholarly journals Finite Difference Energy Method for nonlinear numerical analysis of reinforced concrete slab using simplified isotropic damage model

2014 ◽  
Vol 7 (6) ◽  
pp. 940-964
Author(s):  
M. V. A. Lima ◽  
J. M. F. Lima ◽  
P. R. L. Lima
Keyword(s):  
Reinforced Concrete ◽  
Finite Difference ◽  
Energy Method ◽  
Virtual Work ◽  
Concrete Slab ◽  
Damage Model ◽  
Flexural Behavior ◽  
Structural Element ◽  
Reinforced Concrete Slab ◽  
Reinforced Concrete Slabs

This work presents a model to predict the flexural behavior of reinforced concrete slabs, combining the Mazars damage model for simulation of the loss of stiffness of the concrete during the cracking process and the Classical Theory of Laminates, to govern the bending of the structural element. A variational formulation based on the principle of virtual work was developed for the model, and then treated numerically according to the Finite Difference Energy Method, with the end result a program developed in Fortran. To validate the model thus proposed have been simulated with the program, some cases of slabs in flexure in the literature. The evaluation of the results obtained in this study demonstrated the capability of the model, in view of the good predictability of the behavior of slabs in flexure, sweeping the path of equilibrium to the rupture of the structural element. Besides the satisfactory prediction of the behavior observed as positive aspects of the model to its relative simplicity and reduced number of experimental parameters necessary for modeling.

scholarly journals TENDENCY IN STRUCTURAL ELEMENTS OF BUILDINGS FOCUSED ON REINFORCED CONCRETE SLAB WITHOUT BEAMS

2019 ◽  
Vol 25 (61) ◽  
pp. 1051-1056
Author(s):  
Nagayoshi SOU ◽  
Yoshihisa NAKATA ◽  
Kazuki TAJIMA ◽  
Atsunori MIYATA ◽  
Takumi ARAMAKI ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Structural Elements ◽  
Reinforced Concrete Slab

scholarly journals CALCULATION OF RELIABILITY OF REINFORCED CONCRETE FLIGHT STRUCTURES

2021 ◽  
pp. 18-25
Author(s):  
Roman Kaplin
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Load Capacity ◽  
Element Model ◽  
Operating Conditions ◽  
Structural Element ◽  
Reinforced Concrete Slab ◽  
Bridge Structures ◽  
Number Of Cycles ◽  
Office Software

A large number of bridges are operated on the roads of Ukraine. The increase in the intensity and speed of traffic leads to qualitative changes in the operating conditions of bridge structures, which is characterized by a sharp increase in the number of cycles under load of bridge elements, and to the development of damage in them. For trouble-free operation and efficient use of bridge structures it is very important to have reliable estimates of the actual load capacity and resource, taking into account the loads, material quality, nature of the structure. The solution of the problem in this statement is possible only on the basis of the theory of reliability. However, its application to specific assessments of durability and reliability of structures is associated with the solution of a set of issues: the identification of patterns of change of various parameters, the accumulation of reliable and easy to calculate statistics on loads and mechanical characteristics of materials, etc. It is necessary to know that the strength of the material (sample) of the structural element and the structure as a whole are completely different things. The article considers a new design of reinforced concrete girder structure, using perforated metal elements and an effective reinforced concrete slab of the carriageway. On its basis, a computational model in the form of a finite-element model built in the SCAD-Office software package is formed. As a result of calculations, the components of the stress-strain state of the structure are obtained. Based on the obtained results, the reliability of the structure was calculatedunder the influence of modern regulatory loads. 

scholarly journals Efficiency of ECE Applied on RC Slab using Locally Available Un-Galvanized Steel with Conductive Cement Paste Anode

2020 ◽  
Vol 9 (4) ◽  
pp. 1930-1936
Keyword(s):  
Reinforced Concrete ◽  
Cement Paste ◽  
Concrete Slab ◽  
Research Work ◽  
Chloride Content ◽  
Chloride Ions ◽  
Galvanized Steel ◽  
Current Intensity ◽  
Structural Element ◽  
Reinforced Concrete Slab

Electro-chemical Chloride Extraction (ECE) is considered one of the most effective technique used to extract chloride ions from reinforced concrete structures. Effectiveness of using ECE depends on some important factors such as anode type, current intensity, extraction duration, type of rebar and chemical properties of concrete. On the other hand, ECE may cause some detrimental effects on some mechanical properties of concrete and steel such as a reduction in bond and compressive strengths of concrete, and embrittlement (i.e. reduction in ductility) ductility of reinforcing steel. The major aim of this research work was to investigate the effectiveness of ECE using locally available un-galvanized steel mesh with conductive cement paste anode as a new type of anode on a reinforced concrete slab as a structural element. The slab behavior before and after ECE was studied by determining compressive strength, water absorption rate, concrete chloride content and steel corrosion potential. The slab behavior was studied taken into consideration the established steel arrangement with spacing 20 cm between re-bars. Another aim of this research work was to investigate the effect of initial chloride content on chloride extraction efficiency by applying optimum current intensity and duration (3 A/m2 and 6 weeks) on cylinders with pure chloride content 0.4% and 0.8% (by weight of cement). Effectiveness of ECE with small initial chloride content 0.4% and 0.8% was compared with that of high initial chloride content (2.5%) in order to know if the initial chloride content is an important factor on ECE effectiveness or not.

General

2020 ◽  
Vol 67 (2) ◽  
pp. 292-306
Author(s):  
Ivana Petrovic ◽  
Andrej Petrovic
Keyword(s):  
Comprehensive Analysis ◽  
Structural Elements ◽  
Structural Element ◽  
Cross Sectional ◽  
International Group ◽  
Systematic Overview ◽  
Latin Epic ◽  
Narrative Patterns ◽  
The Individual ◽  
Epic Poems

Structures of Epic Poetry is a monumental, four-volume compendium which aims to classify, analyse, and compare epic structures across Greek and Latin epic poems (and beyond) in a systematic and overarching way. While the individual Bauformen (‘structural elements’) have been the focus of the study of epic for decades, a comprehensive analysis providing a systematic overview of all structural elements in the totality of ancient epic is obviously not a one-person job. The editors, Christiane Reitz and Simone Finkmann, gathered an international group of experts for this herculean task. The compendium provides a set of broad cross-sectional papers on the individual epic structural elements, using a consistent terminology. It has to be said that the editors’ understanding of what constitutes an epic structural element is very broad: it includes the ‘type-scenes’, but also the narrative patterns such as catalogue and ecphrasis, and stylistic hallmarks such as similes; in fact, structural elements as understood by the editors come closest to genre markers.

scholarly journals Reliability of Concrete Elements Designed for Alternative Load Combinations Provided in Eurocodes

10.14311/382 ◽  
2003 ◽  
Vol 43 (1) ◽  
Author(s):  
M. Holický ◽  
J. Marková
Keyword(s):  
Structural Design ◽  
Structural Reliability ◽  
Reliability Theory ◽  
Probabilistic Methods ◽  
European Standard ◽  
Limit States ◽  
Design Procedures ◽  
Characteristic Features ◽  
Concrete Elements ◽  
Ultimate Limit

The basic European standard for design of buildings and other engineering works, EN 1990 "Basis of structural design", provides alternative design procedures, for which national choice is allowed. One of the most important questions concerns three fundamental combinations of actions for persistent and transient design situations in the Ultimate limit states. Simple examples of reinforced concrete elements show, that the alternative load combinations may lead to considerably different reliability levels. Probabilistic methods of structural reliability theory are used to identify characteristic features of each combination and to formulate recommendations. However, further calibration studies are urgently needed in order to prepare National annexes to EN 1990 on time.

scholarly journals TENDENCY IN STRUCTURAL ELEMENTS OF BUILDINGS FOCUSED ON REINFORCED CONCRETE SLAB WITH BEAMS

2020 ◽  
Vol 26 (62) ◽  
pp. 37-42
Author(s):  
Nagayoshi SOU ◽  
Yoshihisa NAKATA ◽  
Kazuki TAJIMA ◽  
Takumi ARAMAKI ◽  
Atsunori MIYATA ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Structural Elements ◽  
Reinforced Concrete Slab

scholarly journals LABORATORY TESTING THE COMBINED ELONGATE STRUCTURAL ELEMENTS OF SUPPORT OF A MINE OPENING

2021 ◽  
Vol 30 (1) ◽  
pp. 20-27
Author(s):  
G. Gasii ◽  
◽  
O. Hasii ◽  
Keyword(s):  
Laboratory Testing ◽  
Strain State ◽  
Concrete Slab ◽  
Triangular Prism ◽  
Structural Elements ◽  
Modular Element ◽  
Reinforced Concrete Slab ◽  
Combined Structure ◽  
Mine Opening ◽  
Service Conditions

The stress-strain state of test specimens of the new combined structure of support of a mine opening under loads is studied. The test specimens are compound modular elements of the designed earlier combined structure of support. Every single modular element is the triangular prism, consisting of a reinforced concrete slab and a steel grid made of tube web members. The slab and web members are grouped in a complete element while concreting the slab. The tension sensor’s method of experimental investigation is applied to the testing specimens. Tests of specimens are carried out under the load forced with cargoes. Loads are set in the ways that to simulate service conditions, counting the most adverse. Design features of the support and test specimens are shown. Particulars of the support and its elements, production technology, assemblies as well as the sizes are briefly described. The methodology of testing specimens, as well as the analysis of the outcomes, are presente.

Serviceability Limit Verification for Structural Elements of Steel Hall

2017 ◽  
Author(s):  
Izabela Skrzypczak ◽  
Grzegorz Oleniacz
Keyword(s):  
Structural Reliability ◽  
Probabilistic Methods ◽  
Steel Beam ◽  
Structural Elements ◽  
Specific Design ◽  
Limit States ◽  
Time Period ◽  
Reliability Indicator ◽  
Design Requirements ◽  
Probabilistic Measures

In recent years, the importance of assessing structural reliability has increased significantly. This is confirmed by the recommendations of the PN-EN 1990 standard. This standard gives the principles and requirements to ensure the safety, serviceability and durability of the structure. It sets out the basis for calculation and verification of the structure and provides guidance to ensure their reliability. Reliability of structure is its ability to meet specific design requirements, taking into account the planned period of use. The planned period of use should be understood as a time period approved in the project, in which the structure or part of it is to be used for their intended purpose, without the need for major repairs. Typically, reliability is expressed by probabilistic measures as indicator of reliability or probability of failure. The aim of this study is to present the results of of roof girder deflection surveying and modeling their reliability. A general algorithm for determining the value of the reliability indicator for the bending steel beam with FORM method will be presented. Verification of the differences between the indicator of reliability obtained by simplified probabilistic methods and compare them with the values recommended in the Eurocode 0 standard will be also shown. For the analyzed steel beam the serviceability limit states were considered.

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