scholarly journals The application of interval calculus in estimation of dynamic characteristics of structures

2012 ◽  
Vol 10 (2) ◽  
pp. 223-234
Author(s):  
Djordje Djordjevic ◽  
Predrag Petronijevic
Keyword(s):  
Reinforced Concrete ◽  
Linear Systems ◽  
Cross Sections ◽  
Dynamic Characteristics ◽  
Modulus Of Elasticity ◽  
Concrete Structure ◽  
Direct Effects ◽  
Reinforced Concrete Structure ◽  
Numerical Example ◽  
Geometrical Characteristics

The paper analyzed application of interval calculus in estimation of dynamic characteristics of linear systems. The eigen periods of oscillation of structures are affected by several parameters: geometrical characteristics of cross sections of members, magnitude of the mass concentrated in the floors and modulus of elasticity of materials. As a numerical example, the frame reinforced concrete structure was taken, for which the mentioned parameters are given in the form interval. The result is also obtained in the form of interval so it is possible to observe the direct effects on the value of the structural oscillation periods by changing one or several parameters.

Calculation Models of the Bearing Capacity of Span Reinforced Concrete Structure Support Zones

2019 ◽  
Vol 968 ◽  
pp. 209-226
Author(s):  
Vasyl M. Karpiuk ◽  
Yulia A. Syomina ◽  
Diana V. Antonova
Keyword(s):  
Reinforced Concrete ◽  
Crack Resistance ◽  
Cross Sections ◽  
Concrete Structure ◽  
Strain State ◽  
Complex Stress ◽  
Deformation Analysis ◽  
Reinforced Concrete Structures ◽  
Reinforced Concrete Structure

Experience gained in design, erection and operation of span reinforced concrete structures has proved that practically all of them are subject to complex stress-strain state. At that, the researchers pay considerable greater attention to calculation of strength, deformation analysis and determination of crack resistance in normal cross-sections than to calculation of their support zones, including oblique sections, which results are generally taken into account for determining the section dimensions and the quantity of the cross reinforcement.

scholarly journals Optimization of a reinforced concrete structure subjected to dynamic wind action

2021 ◽  
Vol 16 (59) ◽  
pp. 326-343
Author(s):  
Jherbyson Brito ◽  
Letícia Miguel
Keyword(s):  
Reinforced Concrete ◽  
Cross Sections ◽  
Concrete Structure ◽  
Frame Structure ◽  
Reinforced Concrete Structure ◽  
Maximum Displacement ◽  
Reinforced Concrete Building ◽  
Synoptic Wind ◽  
Whale Optimization ◽  
Concrete Building

This work proposes a methodology to optimize a reinforced concrete structure. For this, the Whale Optimization Algorithm (WOA) algorithm was used, an algorithm from the group of metaheuristic algorithms, which presents an easy computational implementation. As a study object, a frame structure adapted from a real reinforced concrete building was used, subjected to the dynamic action of artificially generated synoptic wind. The objective function is to reduce the volume of concrete of the structure. For that, the dimensions of the cross-sections were used as design variables, and the maximum displacement at the top imposed by the ASCE / SEI 7-10 standard as a lateral constraint, as well as the maximum story drift between floors. In addition to this structural optimization, it was also proposed the use and optimization of Tuned Mass Dampers (TMD), in different quantities, positions and parameters, improving the dynamic response of the reinforced concrete building. The results show that for this situation it was possible to reduce the concrete volume of the structure by approximately 24%, respecting the maximum limit of displacement at the top required by the standard.

Test and Study on Impact of Corrosion on Bond Force between Steel and Concrete

2010 ◽  
Vol 36 ◽  
pp. 176-181
Author(s):  
Xian Feng He ◽  
Shou Gang Zhao ◽  
Yuan Bao Leng
Keyword(s):  
Reinforced Concrete ◽  
Corrosion Rate ◽  
Concrete Structure ◽  
Steel Corrosion ◽  
Reinforced Concrete Structure ◽  
Bond Force ◽  
Steel Bars ◽  
Protection Layer ◽  
Corrosion Of Steel ◽  
The Impact

The corrosion of steel will have a bad impact on the safety of reinforced concrete structure. In severe cases, it may even be disastrous. In order to understand the impact of steel corrosion on the structure, tests are carried out to study corrosion and expansion rules of steel bars as well as the impact rules of corrosion on bond force between steel and concrete. The results show that wet and salty environment will result in steel corrosion; relatively minor corrosion will not cause expansion cracks of protection layers; when steel rust to a certain extent, it will cause cracks along the protection layer; when there exists minor corrosion in steel and the protection layer does not have expansion cracks, the bond force is still large and rapidly decreases as the corrosion rate increases.

Assessment of the aftertreatment quality of concrete

2021 ◽  
Author(s):  
Lisa Ptacek ◽  
Alfred Strauss ◽  
Clémence Bos ◽  
Martin Peyerl
Keyword(s):  
Reinforced Concrete ◽  
Concrete Structure ◽  
Test Methods ◽  
Reinforced Concrete Structure ◽  
Process Step ◽  
Simple Tool ◽  
Lack Of Control ◽  
Complex Construction

<p>The curing of concrete is extremely important for the durability of a reinforced concrete structure. In practice, due to the complex construction processes, the very limited phases and the lack of control, aftertreatment is often neglected by executing companies. Hence infrastructure operators are therefore very interested in having a robust, simple tool that enables aftertreatment to be easily checked and, as a result, to convey the importance of this process step to the client. In the project presented here, classic and novel test methods are presented and discussed, as well as their suitability for the detection of the aftertreatment quality on laboratory samples and subsequently on some real structures.</p>

scholarly journals Numerical Analysis of a Moderate Fire inside a Segment of a Subway Station

2018 ◽  
Vol 8 (11) ◽  
pp. 2116 ◽  
Author(s):  
Rodrigo Díaz ◽  
Hui Wang ◽  
Herbert Mang ◽  
Yong Yuan ◽  
Bernhard Pichler
Keyword(s):  
Reinforced Concrete ◽  
Surface Temperature ◽  
Concrete Structure ◽  
Fire Test ◽  
Material Behavior ◽  
Sensitivity Analyses ◽  
Subway Station ◽  
Elastic Model ◽  
Reinforced Concrete Structure ◽  
Actual Distribution

A 1:4 scaled fire test of a segment of a subway station is analyzed by means of three-dimensional Finite Element simulations. The first 30 min of the test are considered to be representative of a moderate fire. Numerical sensitivity analyses are performed. As regards the thermal boundary conditions, a spatially uniform surface temperature history and three different piecewise uniform surface temperature histories are used. As regards the material behavior of concrete, a temperature-independent linear-elastic model and a temperature-dependent elasto-plastic model are used. Heat transfer within the reinforced concrete structure is simulated first. The computed temperature evolutions serve as input for thermomechanical simulations of the fire test. Numerical results are compared with experimental measurements. It is concluded that three sources of uncertainties render the numerical simulation of fire tests challenging: possible damage of the structure prior to testing, the actual distribution of the surface temperature during the test and the time-dependent high-temperature behavior of concrete. In addition, the simulations underline that even a moderate fire represents a severe load case, threatening the integrity of the reinforced concrete structure. Tensile cracking is likely to happen at the inaccessible outer surface of the underground structure. Thus, careful inspection is recommended even after non-catastrophic fires.

Sign in / Sign up

Export Citation Format

Share Document