The Study of Butt-Welded Connections after Fire Exposure

2017 ◽  
Vol 21 ◽  
pp. 129-134 ◽  
Author(s):  
Teofil Florin Galatanu ◽  
Georgeta Băetu ◽  
Christiana Cazacu ◽  
Dorin Radu ◽  
Radu Muntean ◽  
...  
Keyword(s):  
Damage Assessment ◽  
Steel Structure ◽  
Fire Exposure ◽  
Structural Elements ◽  
Fire Behaviour ◽  
Experimental Part ◽  
Eurocode 3 ◽  
Strengthening Technique ◽  
Increasing Temperature ◽  
Steel Properties

The paper presents a study of fire behaviour of butt-welded connections taken into account the post fire conditions and the possibility of welding strengthening of fire exposed structures. The need of in service life of a steel structure after being exposed to fire raises the problem of strengthening or replacement of some structural elements. The degradation of steel properties with increasing temperature is considered according to Eurocode 3: Part 1-2 provisions. Following the experimental part, the behavior of the welded connections after fire exposure was compared with the original behaviour at the ambient temperature. The results and conclusions can be used for damage assessment and strengthening technique of post fire steel structure.

scholarly journals Kajian Analisis Respon Struktur Bangunan Baja di Bawah Pengaruh Kombinasi Beban Termal (Kebakaran) dan Beban Angin. (Hal. 13-25)

2019 ◽  
Vol 5 (2) ◽  
pp. 13
Author(s):  
Amatulhay Pribadi
Keyword(s):  
Thermal Load ◽  
Stress Ratio ◽  
Steel Structure ◽  
Structural Elements ◽  
Structural Element ◽  
Temperature Load ◽  
Critical Thermal Load ◽  
Steel Properties

ABSTRAKBeban termal yang terjadi pada bangunan dapat mengakibatkan degradasi pada struktur baja dan menyebabkan keruntuhan. Penelitian ini menganalisis pengaruh beban termal disertai beban angin terhadap respon dari struktur bangunan baja lima belas lantai yang berfungsi sebagai perkantoran dengan mempertimbangkan degradasi propertis baja, reduksi beban hidup dan beban mati tambahan, serta kecepatan penanganan pemadaman. Simulasi terbagi menjadi tiga kasus yaitu penanganan pemadaman kebakaran cepat, penanganan pemadaman kebakaran lambat, dan penentuan beban termal kritis. Analisis struktur dilakukan dengan bantuan software ETABS. Hasil simulasi kebakaran menunjukkan semakin tinggi temperatur maka stress ratio dari elemen struktur makin membesar. Pada penentuan beban termal kritis diperoleh bahwa besar beban termal yang dapat menyebabkan minimal satu elemen struktur utama mengalami kegagalan pada umumnya berbeda pada lantai level bawah, tengah, dan atas. Pada studi kasus ini diperoleh beban temperatur kritis paling besar yaitu pada lantai level atas.Kata kunci: beban termal, degradasi propertis baja, kegagalan struktur ABSTRACTThermal load on the building can lead into the degradation of steel structure and cause collapse. This study analyze the effect of thermal along with wind loads on the response of fifteen stories steel structure building which serves as an office by considering the degradation of steel properties, the reduction of live load and super imposed dead load, and the speed of handling the extinguishing. This simulation is divided into three cases which are fast handling of extinguishing, slow handling of extinguishing, and the determination of the critical thermal load. Structural analysis will be done using the ETABS software. The result of fire simulation showed that when the temperature is higher, the stress ratio of structural elements will also expand. In the determination of the critical thermal load, it is obtained that the thermal loads which can cause failure in minimum one major structural element are generally different at the bottom, middle, and top level of stories. In this case study, the highest critical temperature load is on the top level.Keywords: thermal load, steel properties degradation, structure failure

Calculation Method of Butt-Welded Connection of Steel Structure Post Fire

2011 ◽  
Vol 189-193 ◽  
pp. 3629-3632
Author(s):  
Jian Feng Chen
Keyword(s):  
Experimental Data ◽  
High Temperature ◽  
Theoretical Analysis ◽  
Damage Assessment ◽  
Room Temperature ◽  
Steel Structure ◽  
Analysis Method ◽  
Design Value ◽  
Welded Connection ◽  
Strengthening Technique

In order to study the load-bearing properties of butt-welded connection of steel structure post fire, the strength design value of weld connection post-fire is proposed based on the experimental data and theoretical analysis. Considering the influence of different high temperatures and cooling patterns on strength damage of the weld, a revised checking method for strength of butt-welded connection of steel structure after high temperature is established on the basis of the analysis method for strength of butt-welded connection of steel structure at room temperature. The method can be used for damage assessment and strengthening technique of steel structure post fire.

Automated Damage Assessment and Structural Modeling of Bridges with Visual Sensing Technology

2021 ◽  
Author(s):  
Yujie Yan ◽  
Jerome F. Hajjar
Keyword(s):  
Finite Element ◽  
Damage Assessment ◽  
Laser Scanning ◽  
Sensor Data ◽  
Structural Elements ◽  
Visual Sensor ◽  
Bridge Inspection ◽  
Visual Sensing ◽  
Sensing Technology ◽  
Laser Scanners

Recent advances in visual sensing technology have gained much attention in the field of bridge inspection and management. Coupled with advanced robotic systems, state-of-the-art visual sensors can be used to obtain accurate documentation of bridges without the need for any special equipment or traffic closure. The captured visual sensor data can be post-processed to gather meaningful information for the bridge structures and hence to support bridge inspection and management. However, state-of-the-practice data postprocessing approaches require substantial manual operations, which can be time-consuming and expensive. The main objective of this study is to develop methods and algorithms to automate the post-processing of the visual sensor data towards the extraction of three main categories of information: 1) object information such as object identity, shapes, and spatial relationships - a novel heuristic-based method is proposed to automate the detection and recognition of main structural elements of steel girder bridges in both terrestrial and unmanned aerial vehicle (UAV)-based laser scanning data. Domain knowledge on the geometric and topological constraints of the structural elements is modeled and utilized as heuristics to guide the search as well as to reject erroneous detection results. 2) structural damage information, such as damage locations and quantities - to support the assessment of damage associated with small deformations, an advanced crack assessment method is proposed to enable automated detection and quantification of concrete cracks in critical structural elements based on UAV-based visual sensor data. In terms of damage associated with large deformations, based on the surface normal-based method proposed in Guldur et al. (2014), a new algorithm is developed to enhance the robustness of damage assessment for structural elements with curved surfaces. 3) three-dimensional volumetric models - the object information extracted from the laser scanning data is exploited to create a complete geometric representation for each structural element. In addition, mesh generation algorithms are developed to automatically convert the geometric representations into conformal all-hexahedron finite element meshes, which can be finally assembled to create a finite element model of the entire bridge. To validate the effectiveness of the developed methods and algorithms, several field data collections have been conducted to collect both the visual sensor data and the physical measurements from experimental specimens and in-service bridges. The data were collected using both terrestrial laser scanners combined with images, and laser scanners and cameras mounted to unmanned aerial vehicles.

scholarly journals Flexural Behavior of Fire-Damaged Prefabricated RC Hollow Slabs Strengthened with CFRP versus TRM

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2556
Author(s):  
Zheng-Ang Sui ◽  
Kun Dong ◽  
Jitong Jiang ◽  
Shutong Yang ◽  
Kexu Hu
Keyword(s):  
Failure Modes ◽  
Early Stage ◽  
Load Capacity ◽  
Peak Load ◽  
Flexural Behavior ◽  
Masonry Building ◽  
Fire Exposure ◽  
Standard Fire ◽  
Four Point Bending ◽  
Strengthening Technique

In this paper, carbon fiber reinforced polymer (CFRP) and textile reinforced mortar (TRM) strengthening techniques were proposed to retrofit and strengthen fire-damaged prefabricated concrete hollow slabs. A total of six slabs, from an actual multi-story masonry building, were tested to investigate the flexural performance of reinforced concrete (RC) hollow slabs strengthened with TRM and CFRP. The investigated parameters included the strengthening method (CFRP versus TRM), the number of CFRP layers, and with or without fire exposure. One unstrengthened slab and one TRM strengthened slab served as the control specimens without fire exposure. The remaining four slabs were first exposed to ISO-834 standard fire for 1 h, and then three of them were strengthened with CFRP or TRM. Through the four-point bending tests at ambient temperature, the failure modes, load and deformation response were recorded and discussed. Both CFRP and TRM strengthening methods can significantly increase the cracking load and peak load of the fire-damaged hollow slabs, as well as the stiffness in the early stage. The prefabricated hollow slabs strengthened by CFRP have better performance in the ultimate bearing capacity, but the ductility reduced with the increase of CFRP layers. Meanwhile, the TRM strengthening technique is a suitable method for the performance improvement of fire-damaged hollow slabs, in terms of not only the load capacity, especially the cracking load, but also the flexural stiffness and deformation capacity.

scholarly journals Assessment of technical condition and repair of steel structure elements on the example of fire damage in a warehouse building

2019 ◽  
Vol 284 ◽  
pp. 02001
Author(s):  
Andrzej Ambroziak ◽  
Paweł Piotrkowski ◽  
Tomasz Heizig
Keyword(s):  
Steel Structure ◽  
External Source ◽  
Technical Condition ◽  
Actual Condition ◽  
Test Results ◽  
Structural Elements ◽  
Site Investigations ◽  
Laboratory Test Results ◽  
Repair Procedure

The paper analyses a case study on the structural assessment of warehouse building partially damaged by fire caused by external source (fire of lorries close to the building). The authors focus on the site investigations and laboratory test results prior to assessing actual condition of the structural elements. Both strengthening concept and repair procedure of a steel column are addressed here. A short literature survey in the paper regards fire damages and its impact on the entire structural systems and its members.

Monitoring of Deformation of Steel Structure-Roof of Football Stadium Slavia Prague

2012 ◽  
Vol 239-240 ◽  
pp. 622-630 ◽  
Author(s):  
Jiri Litos ◽  
Eva Vejmelková ◽  
Petr Konvalinka
Keyword(s):  
Experimental Investigation ◽  
Numerical Analysis ◽  
Large Scale ◽  
Steel Structure ◽  
Horizontal Direction ◽  
Structural Elements ◽  
Stress Levels ◽  
The Individual ◽  
Football Stadium

Monitoring of deformation of structure in large scale in situ is introduced. The steel roof of football stadium Slavia in Prague is a new progressive structure. Realization of the stadium roof was changed over the project, so it was necessary to verify the rigidity of the steel structure in horizontal direction. The experimental investigation was repeatedly conducted in three different stress levels and than monitoring of behaviour of the individual structural elements of the steel structure was compared with the numerical analysis.

scholarly journals Development of a GUI Based Program for Design of various Steel Connections

2021 ◽  
Vol 9 (VI) ◽  
pp. 5151-5164
Author(s):  
Mahe Farkhar
Keyword(s):  
Ductile Failure ◽  
Steel Structure ◽  
Structural Elements ◽  
Large Uncertainty ◽  
Steel Connections ◽  
Frame Buildings ◽  
Steel Frame Buildings ◽  
Different Types ◽  
The Cost ◽  
User Friendly

Steel frame buildings consist of a number of different types of structural elements. Every element must be attached properly to its neighbouring part of structure. This will involve use of various types of connections. Connections account for more than half the cost of structural steel work. Connection failure is not a ductile failure and hence it should be avoided before member failure. Large uncertainty is there in the design of connections. Connections are usually the most vulnerable part of the structure, failure of which may lead to the failure of whole structure. Thus, design of connection is an important and integral part of design of the steel structure. This MATLAB GUI program developed will be a very useful and user-friendly tool for the design of connections.

Analysis of Columns Strengthened using Fibre Reinforced Cementitious Matrix Jackets

2021 ◽  
Vol 9 (9) ◽  
pp. 1795-1800
Author(s):  
Fathima Azad
Keyword(s):  
Steel Plates ◽  
Structural Elements ◽  
Near Surface ◽  
Rc Structures ◽  
Cementitious Matrix ◽  
Reinforced Polymer ◽  
Externally Bonded ◽  
Fibre Reinforced Polymer ◽  
Near Surface Mounted ◽  
Strengthening Technique

Abstract: Maintenance, repair and strengthening of existing concrete structures, either reinforced or prestressed,are important activities of civil engineers. Nowadays different techniques are available for the strengthening. Various techniques were adopted for strengthening RC structures, namely, steel plates, external post tensioning, externally bonded Fibre-Reinforced Polymer (FRP), and near- surface-mounted FRP systems to increase shear and flexural capacity. During the last few decades, strengthening of concrete structural elements by fibre-reinforced polymer has become a widely used technique. But it has several disadvantages due to the epoxy resin like debonding of FRP from the concrete structure, unstable nature of the epoxy at higher temperatures etc. To overcome this, an upgraded system was introduced as an alternative for FRP known as Fibre Reinforced Cementitious Matrices (FRCM). The objective of this paper is to investigate the feasibility of Fibre-Reinforced Cementitious-Matrix materials as an alternative external strengthening technique for RC members. Columns with circular geometry were wrapped with different fibre materials using cementitious matrix. The analysis was done using ANSYS software. Keywords: RC columns, FRCM, Strengthening, fibre, ANSYS

scholarly journals Damage assessment and seismic behavior of steel buildings during the Mexico earthquake of 19 September 2017

2020 ◽  
Vol 36 (1) ◽  
pp. 250-270 ◽  
Author(s):  
Edgar Tapia-Hernández ◽  
J. Salvador García-Carrera
Keyword(s):  
Mexico City ◽  
Damage Assessment ◽  
Structural Damage ◽  
Steel Structures ◽  
Structural Elements ◽  
Steel Buildings ◽  
Ground Shaking ◽  
Design Procedures ◽  
Mexico Earthquake ◽  
Epicentral Region

During the 19 September 2017 earthquake, steel buildings in the States of Morelos, Puebla, Mexico, and Mexico City were subjected to severe ground shaking. Despite in some cases, moderate damages in non-structural elements were developed; generally, null or minor structural damage was reported. The notable exceptions are (1) a three-stories building located at the southern area of Mexico City and (2) some schools near to the epicentral region in the State of Morelos. The behavior of these buildings is analyzed in detail. Conclusions are drawn on the demands imposed on steel structures considering the actual demands in order to underline the relevance of the normative design procedures.

scholarly journals The Usage of Alternative Materials to Optimize Bus Frame Structure

Symmetry ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1010 ◽  
Author(s):  
Tautvydas Pravilonis ◽  
Edgar Sokolovskij ◽  
Artūras Kilikevičius ◽  
Jonas Matijošius ◽  
Kristina Kilikevičienė
Keyword(s):  
Dynamic Properties ◽  
Steel Structure ◽  
Frame Structure ◽  
Structural Elements ◽  
Resonant Frequencies ◽  
Centre Of Gravity ◽  
Alternative Materials ◽  
Structural Frame ◽  
Strength And Stiffness ◽  
Key Indicators

The strength and stiffness of the frame is one of the key indicators of vehicle structures. Insufficient stiffness causes vibration and noise, and is also less comfortable for both the passengers and the driver. Symmetry is required between the strength and comfort of the structural frame, which depends on vibration and noise. This article analyses the frame of the structure of a medium-sized passenger bus and its dynamic properties, when replacing materials of structural elements which do not affect the symmetry of the structure. The conducted theoretical and experimental modal analysis of the bus, allows for evaluating dynamic parameters and validating the theoretical model based on the experimental results. The optimization of the medium-sized passenger bus frame—by replacing the material of the ancillary frame elements with fiberglass—reveals that its dynamic characteristics change by up to 20%, comparing the values of the first three resonant frequencies with those of the steel structure. The obtained results show that replacing the material of ancillary frame elements with fiberglass, while maintaining the symmetrical arrangement of the elements in the structure, does not change the safety characteristics of the structure, reducing the mass of the frame by 11%, and shifting the coordinate of the centre of gravity vertically downwards, which is very important for stability, comfort and fuel consumption.

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