scholarly journals Risk aided design of building structures

2014 ◽  
Vol 13 (2) ◽  
pp. 367-374
Author(s):  
Szczepan Woliński

The potential failure of building structures usually arises from a combination of many unspecified causes or catastrophic events whose statistical description is highly uncertain and often impossible. Assumed or calculated reliability of the structure in a case is just a notional measure that can be used to compare the relative safety level of different structures in similar circumstances. Due to the difficulties associated with the estimation of the probability of different hazards as well as the assessment of consequences and costs of the structural damage and failure, also the risk analysis provides very uncertain information on the actual level of safety of a structure. The paper presents a proposal for an indirect approach to the probabilistic design of structures based not only on specific actions, but also on the ability of the structure to survive in the unique , unusual and vaguely defined circumstances. It requires a preliminary risk analysis before the standard procedures for shaping and dimensioning design elements will be applied.

2018 ◽  
Vol 230 ◽  
pp. 02023 ◽  
Author(s):  
Yuriy Otrosh ◽  
Andrii Kovalov ◽  
Oleg Semkiv ◽  
Irina Rudeshko ◽  
Valentin Diven

The paper proposes an approach to determining the increase of the normative lifetime of building structures on the basis of the algorithm of numerical calculation of the residual life of structures, which is performed on the basis of the results of defining parameters obtained during the technical examination and evaluation of defects, failures and structural damage. To calculate the structures, the simulation of the stressstrain state of the building structures with the involvement of OK LIRA was used. Simulation allowed performing optimization of technical solutions and strengthening of structures for buildings. The methodology is used to design elements for strengthening the structures of buildings and structures. Reliable estimation and forecasting of the technical condition enables to prevent the occurrence of accidents of structures and their associated losses, to use rational use of funds for current and capital repairs, and to regulate the technical condition in such a way as to achieve the most effective use of fixed assets.


2021 ◽  
pp. 12-17
Author(s):  
Юрий Николаевич Шебеко ◽  
Алексей Юрьевич Шебеко

Проведен краткий анализ понятий, связанных с расчетом пределов огнестойкости строительных конструкций. Дано определение термина «фактический предел огнестойкости», которое отсутствует в нормативных документах по пожарной безопасности. Отмечено, что это связано с использованием на практике значений пределов огнестойкости, определенных для стандартных температурных режимов пожара, в то время как на практике указанные температурные режимы, как правило, отличаются от стандартных. Предложена концепция определения фактического предела огнестойкости, основанная на моделировании воздействия на строительную конструкцию температурного режима реального пожара (например, с помощью программного комплекса FDS 6). The brief analysis of definitions connected with estimation of fire resistance limits of building structures is conducted. There is given the determination of term “actual fire resistance limit” that is absent in fire safety normative documents. It is caused by practical application of the fire resistance limits determined for standard temperature regimes of fires only, but at the same time the temperature regimes of real fires as a rule differ from the standard regimes. There is proposed the method for determination of the actual fire resistance limit based on the modeling of influence of the real fire temperature regime on buildings structures. This modeling can be made by an application of CFD methods (for example, with the help of FDS 6 software complex). The required reliability of the building structure is considered. The proposed method can solve the problem of practical applicability of certain structural unit during designing buildings and structures, for which the use of the resistance limits obtained for the standard fire temperature regimes can lead to unjustified economic expenditures without an appropriate elevation of fire safety level of the object.


2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Hezheng Bi ◽  
Linjun Lu ◽  
Jian Lu ◽  
Chen Wang

Evaluating safety performance of first-class highways in China is important due to their high mortality rates. Traditional models for statistical crash prediction and traffic conflict techniques require long periods of data collection which is time-consuming and labor-intensive. This paper introduces a safety evaluation method based on catastrophe theory for highways in China. The method firstly divides the highway into multiple road sections and uses video-based road detection (VRD) system to collect video data of existing road conditions. Then, experienced drivers and experts are invited to watch the collected videos to establish a multilayer safety index system and assign values to bottom indexes. By applying catastrophe theory, a general safety index is derived, which indicates the relative safety level of a road section. Finally, all road sections can be ranked based on the general safety index. A case study shows encouraging results where (1) the safety index is highly correlated with real mortality rates and (2) the safety index successfully identifies most dangerous road sections. The proposed method can be considered as a promising supplementary safety evaluation method that could help traffic engineers to better understand safety implications of first-class highways in China.


Author(s):  
Valentina V. Kuzlyakina ◽  
Marina V. Nagaeva

Laboratory work is an important element in engineering training, which should correspond to up-to-date tendencies in computer-based technologies in design, production, maintenance and preserving mechanisms. Computer-based laboratory work consists of 16 assignments. Seven assignments are carried out on laboratory stands, the remainder are provided on PC, using programs like “Visual Structure Editor”, “DYNAMO”, “APM Win Machine”. The system Visual Structure Editor (VSE) is designed by specialists of “Machine Mechanics and Computer-Aided Design” department, of the Maritime State University named after adm.G.I.NEVELSKOY, Vladivostok, under the direction of prof. Valentina V. Kuzlyakina. The system APM (Automated Projecting of Mechanism) is designed by the research-and-production centre “APM” under the direction of prof.V.Shelofast, from the city of Korolyov, Moscow area. These systems are multifunctional. They allow project different mechanical systems at the stage of structural and parametrical synthesis, carry out strength calculations and design elements of machines and mechanisms. They are good in operation. Teachers and students easily master the systems. Laboratory works with computer support allow students to pass from a concrete object to modeling on a PC, and to solve complex engineering tasks during the education process.


2017 ◽  
Vol 24 (24) ◽  
pp. 5854-5866 ◽  
Author(s):  
Amin Hosseini ◽  
Touraj Taghikhany ◽  
Arash Yeganeh Fallah

In recent decades, the application of semi-active control strategies has gained much attention as a way to reduce the seismic response of civil infrastructures. However, uncertainty in the modeling process of systems with possible partial or total failure during an earthquake is the main concern of engineers about the reliability of this strategy. In this regard, adaptive control algorithms are known as an effective solution to adjust control parameters with different uncertainties. In the current study, the efficiency of the simple adaptive control method (SACM) is investigated to control the seismic response of building structures in the presence of unknown structural damage and fault in the sensors. The method is evaluated in 20-story steel moment resisting frames with different arrangement of smart dampers and sensors with various damage and fault scenarios. The results show that the SACM control system can effectively reduce the maximum inter-story drift of the structure in all different assumed magnetorheological damper arrangements. Furthermore, combination of a Kalman–Bucy filter with the SACM improves robustness of the controller to the uncertainties of sensors faults and damages of structural elements.


2014 ◽  
Vol 899 ◽  
pp. 535-538 ◽  
Author(s):  
Karel Kubečka ◽  
Pavel Vlček ◽  
Darja Kubečková

The paper introduces an alternative method for damage pricing on buildings in consequence of defects, failures and collapses. The method operates with time-independent price of the structure and following damage on the construction. Using risk analysis methods, the price is reduced depending on technical condition to proper damage and evaluation of the object, building or structure.


2018 ◽  
Vol 24 ◽  
pp. 25-29
Author(s):  
Páll Einarsson ◽  
Haukur Jóhannesson ◽  
Ásta Rut Hjartardóttir

Straddling the boundary between two of the major tectonic plates on Earth, Iceland offers unique conditions for engineering structures that require special attention. Urban areas are rapidly expanding into areas where the bedrock is cut by numerous active fractures and faults. The fissure swarm of the Krísuvík volcanic system runs through the outskirts of Reykjavík and other towns of the metropolitan area. Activity of its fractures mostly occurs during magmatic events along the Reykjanes Peninsula oblique rift on a thousand years timescale. Hazard caused by the fractures is mostly twofold: Relative displacement of the walls of the fracture during magmatic intrusion and small relative displacements during the passage of seismic waves from distant earthquakes may damage structures built across them. The risk of structural damage may most likely be reduced considerably by avoiding building structures across the fractures. We suggest a change in building practice in fractures areas to achieve that.


2020 ◽  
Vol 21 (1) ◽  
pp. 105 ◽  
Author(s):  
Eric Lainé ◽  
Jean-Claude Grandidier ◽  
Maxime Cruz ◽  
Anne-Laure Gorge ◽  
Claire Bouvy ◽  
...  

The aim of this paper is to study the damage mechanisms in a sandwich polymer structure that contains three layers: two polyolefin skins and the foam core (skin–foam–skin). Specific tests on structure associated with the acoustic emission (AE) technique and tomographic observations (RX) are used to identify the damage. Initially, a conventional tensile test was performed to correlate the acoustic emission with the initiation of plasticity and damage to a polyethylene sample. The results obtained are close to those observed in other studies and it is possible to separate the signal from cavitation and propagation of necking. The technique is then employed to capture the rupture of a polymer skin on a multilayer rotomoulded structure (bottle). Tests were carried out on this bottle under internal water pressure. Three tests are performed with more or less early interruptions in order to identify the first damage and understand their evolution. Different quantities (average frequency, RA value, etc.) are observed in order to quantify and understand the perceived damage. With the AE/RX correlation and mechanical behaviour, a scenario of structural damage is proposed.


2014 ◽  
Vol 611 ◽  
pp. 416-423
Author(s):  
Cyril Klimeš ◽  
Radim Farana

Decision support systems mean interactive computer systems, which assist to decision making subjects to utilize both data and models to solve non-structured issues. These systems were established mainly on the basis of a risk analysis, utilizing the experience/skills, conclusion making and intuition, enabling very fast and flexible analysis with a good response, enabling the application of manager intuition and judgment this way. However, such decisions are often based on uncertain information. This fact requires the establishment of other decision support models.


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