scholarly journals Analysis of the load-bearing capacity of timber members exposed to fire

2018 ◽  
Vol 247 ◽  
pp. 00009
Author(s):  
Kamil Kmiecik ◽  
Tomasz Domański
Keyword(s):  
Bearing Capacity ◽  
Cross Sections ◽  
Environmental Influence ◽  
High Energy ◽  
Building Structures ◽  
Safety Requirement ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Finite Element Software ◽  
Numerical Studies

Members of building structures are often made of wood. There are many advantages of using timber, such as quick erection time, good environmental influence and high energy efficiency. But the fire safety requirement is one of the most important issues concerning the design of timber structures. Safe use in structures depends on a proper knowledge and modelling of the chemical and physical reactions related to the increase of temperature inside the timber members. This paper presents a summary of results from numerical studies on the heat transfer through timber members exposed to fire from different sides. The finite element software SAFIR was used to make two-dimensional thermal models of the timber elements. Then the FE models were used to analyze the heat flow within the members under standard ISO-fire exposure interacting from different sides. On the basis of the 300 °C isotherms, residual cross-sections were determined. Then, the load-bearing capacity of the elements exposed to fire from different sides was determined. The obtained results showed that the location of construction members against the fire has a significant impact of the temperature distribution in the cross-section and, as a result, on the load-bearing capacity of the timber members.

scholarly journals Load Bearing Capacity Calculation of the System “Reinforced Concrete Beam – Deformable Base” under Torsion with Bending

2019 ◽  
Vol 97 ◽  
pp. 04059 ◽  
Author(s):  
Alexey Dem’yanov ◽  
Vladymir Kolchunov ◽  
Igor Iakovenko ◽  
Anastasiya Kozarez
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Cross Sections ◽  
Concrete Beam ◽  
Equations Of State ◽  
Reinforced Concrete Beam ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Deformable Base ◽  
The Relationship

It is presented the formulation and solution of the load bearing capacity of statically indeterminable systems “reinforced concrete beam – deformable base” by spatial cross-sections under force and deformation effects. The solution of problem is currently practically absent in general form. It has been established the relationship between stresses and strains of compressed concrete and tensile reinforcement in the form of diagrams. The properties of the base model connections are described based on a variable rigidity coefficient. It is constructed a system of n equations in the form of the initial parameters method with using the modules of the force (strain) action vector. The equations of state are the dependences that establish the relationship between displacements which are acting on the beam with load. Constants of integration are determined by recurrent formulas. It makes possible to obtain the method of initial parameters in the expanded form and, consequently, the method of displacements for calculating statically indefinable systems. The values of the effort obtained could be used to determine the curvature and rigidity of the sections in this way. It is necessary not to set the vector modulusP, the deformation is set in any section (the module is considered as an unknown) during the problem is solving. This allows us to obtain an unambiguous solution even in the case when the dependence M–χ has a downward section, i.e one value of moment can correspond to two values of curvature.

LOAD-BEARING CAPACITY OF CONCRETE-FILLED STEEL COLUMNS

2009 ◽  
Vol 15 (1) ◽  
pp. 21-33 ◽  
Author(s):  
Artiomas Kuranovas ◽  
Douglas Goode ◽  
Audronis Kazimieras Kvedaras ◽  
Shantong Zhong
Keyword(s):  
Bearing Capacity ◽  
Cross Section ◽  
Cross Sections ◽  
Rectangular Cross Section ◽  
Circular Cross Section ◽  
Steel Tube ◽  
Sustained Load ◽  
Load Bearing Capacity ◽  
Concrete Core ◽  
Load Bearing

This paper represents the analysis of 1303 specimens of CFST experimental data. Test results are compared with EC4 provided method for determining the load‐bearing capacity of these composite elements. Several types of CFSTs were tested: both circular and rectangular cross‐sections with solid and hollow concrete core with axial load applied without and with moment, with sustained load and preloading. For circular cross‐section columns there is a good agreement between the test failure load and the EC4 calculation for both short and long columns with and without moment. For rectangular cross‐section columns the agreement is good except when the concrete cylinder strength was greater than 75 MPa, when many tests failed below the strength predicted by EC4. Preloading the steel tube before filling with concrete seems to have no effect on the strength. This paper also presents the stress distribution, confinement distribution and complete average longitudinal stress‐strain curves for concrete‐filled steel tubular elements. Based on the definition of the “Unified Theory”, the CFST is looked upon as an entity of a new composite material. In this paper, the research achievement of the strength and stability for centrifugal‐hollow and solid concrete filled steel tube are introduced. These behaviours relate to the hollowness ratio and the confining indexes of corresponding solid CFST. If the hollow ratio equals to 0,4–0,5 and over, the N‐ϵ relationship exists in steady descending stage. The critical stress of CFST elements stability is determined as an eccentric member with the initial eccentricity by use of finite element method. Santrauka Straipsnyje analizuojami 1303 betonšerdžių plieninių strypų bandinių eksperimentiniai duomenys. Duomenys lyginami su eurokode 4 pateiktais kompozitinių elementų laikomosios galios nustatymo metodais. Analizuojami šie betonšerdžių plieninių strypų bandinių tipai: pilnaviduriai ir tuščiaviduriai, apskrito ir stačiakampio skerspjūvio kolonos, kurių galuose veikia arba neveikia momentas, su iš anksto pridėta arba ilgalaike apkrova. Apskrito skerspjūvio kolonų laikomosios galios bandymų rezultatai atitinka skaičiavimų reikšmes, apskaičiuotas pagal eurokode 4 pateiktu metodu. Stačiakampio skerspjūvio elementų laikomosios galios reikšmių bandymo rezultatai puikiai atitinka teorines reikšmes, kai betono ritininis stipris nesiekia 75 MPa. Išankstinis elementų apkrovimas poveikio elementų laikomajai galiai beveik neturi. Taip pat nagrinėjami betonšerdžių elementų įtempių būvių pasiskirstymas, betono apspaudimo poveikis ir išilginių deformacijų ir įtempių kreivės. Pateikiama S. T. Zhong „Unifikuota teorija“, kuri nagrinėja kompozitinį elementą kaip visumą. Straipsnyje nagrinėjamos kompozitinio plieninio ir betoninio elemento stiprumo ir pastovumo sąlygos. Tokių elementų reikšmėmis. Jeigu tuštumos santykis lygus 0,4–0,5 ir daugiau, N-ε sąryšis yra kritimo stadijoje. Elgsenos stadijos keičiasi pagal tuštumos koeficientą.

Research on Deflection Calculation of Laminated Glass Simply Supported on Four Sides

2011 ◽  
Vol 341-342 ◽  
pp. 833-837
Author(s):  
Xun Wang ◽  
Qi Lin Zhang ◽  
Jun Chen ◽  
Zhi Xiong Tao ◽  
Jun Chen
Keyword(s):  
Finite Element ◽  
Bearing Capacity ◽  
Correction Coefficient ◽  
Laminated Glass ◽  
Load Bearing Capacity ◽  
Equivalent Thickness ◽  
Curtain Wall ◽  
Load Bearing ◽  
Simply Supported ◽  
Finite Element Software

Combining with load bearing capacity tests, the laminated glass simply supported on four sides subjected to bending is analyzed using the finite element software ANSYS. Based on the theoretical and experimental deflection results, the accurate calculation model is established. In order to calculate the deflection of laminated glass subjected to short-time loading such as wind load based on different codes, the equivalent thickness of laminated glass based on Chinese code 2003 and European code is calculated, respectively. Finally, on the basis of many finite element analyses, load bearing capacity tests and code values, the formulas for calculating maximum deflectiont of four-sides supported laminated glass is revised in “Technical code for glass curtain wall engineering” (China) and corresponding correction coefficient is given.

scholarly journals Influence of the Ribs Parallel to Web on Warping and Load-Bearing Capacity of a Steel I-Beam

2019 ◽  
Vol 29 (4) ◽  
pp. 141-148 ◽  
Author(s):  
Krzysztof Wierzbicki ◽  
Maciej Szumigała
Keyword(s):  
Bearing Capacity ◽  
Cross Sections ◽  
Steel Plates ◽  
Steel Beam ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Plane Parallel ◽  
Steel Members ◽  
Plane Bending ◽  
The Web

Abstract The article analyses the method of enhancing a steel beam by adding additional steel members like ribs. They are rigidly connected with both flanges in a plane parallel to the web. That plates reduces warping during in-plane bending of steel beam under lateral-torsional bucking. Different thicknesses of steel plates used as ribs and different cross-sections were taken into account. Calculations were conducted using FEM and ABAQUS CAE environment. The outcomes were compared with ones from previous studies which concerned an influence of endplates on load-bearing capacity of an I-beam.

Narrow Reinforced Concrete Slabs after their Flexural Destruction

2014 ◽  
Vol 969 ◽  
pp. 271-275 ◽  
Author(s):  
Mirosław Wieczorek
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
The Self ◽  
Concrete Slabs ◽  
Building Structures ◽  
Reinforcing Steel ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Horizontal Shift ◽  
Reinforced Concrete Slabs

In the course of the exploitation of building structures frequently situations turn up, in which the structure is not adequately used (it may, for instance, be exposed to considerably greater loads than previously been intended). In the state of an unforeseen overload of the structure, essential reserves of their load-bearing capacity may be disclosed in the case of the self-acting work as a flexible strand. The paper presents the results of investigations concerning the influence of the parameters of reinforcing steel on the mechanism of the destruction of six single-span models of narrow reinforced concrete slabs, in which a horizontal shift of the supports was not possible. The tests were carried out on narrow slabs with the dimensions 3860×480×100 mm. The results of the tests were compared with analytical calculations.

Experimental Research and Finite Element Analysis on the Axial Pressure Bearing Capacity of Steel skeleton-Steel Pipe Reinforced Composite Concrete Columns

2012 ◽  
Vol 204-208 ◽  
pp. 995-998
Author(s):  
Yun Yun Li ◽  
Bao Sheng Yang
Keyword(s):  
Finite Element ◽  
Bearing Capacity ◽  
Concrete Columns ◽  
Steel Pipe ◽  
Axial Pressure ◽  
Load Bearing Capacity ◽  
Element Analysis ◽  
Load Bearing ◽  
Finite Element Software ◽  
Reinforced Composite

This paper studies the working mechanism, ductility, and ultimate load bearing capacity of the composite columns through axial load bearing capacity experiments on eight steel skeleton-steel pipes reinforced composite concrete columns. The results show that the collaborative work between the steel pipe, steel skeleton and concrete can effectively improve the bearing capacity of the column, delay or inhibit the spread of shear diagonal cracks in the concrete and improve the ductility of the column. In addition, the finite element software ANSYS is used to digitally simulate the whole process of axial pressure test, and the resulting load-displacement curves and experimental curves agree fairly well.

scholarly journals Sustainable Recycling of High-Strength Concrete as an Alternative to Natural Aggregates in Building Structures

2021 ◽  
Vol 13 (8) ◽  
pp. 4286
Author(s):  
Barbara Sadowska-Buraczewska ◽  
Małgorzata Grzegorczyk-Frańczak
Keyword(s):  
Bearing Capacity ◽  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Recycled Aggregate ◽  
Building Structures ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Lower Load ◽  
Natural Aggregates

The application of recycled coarse aggregates (RCA) in high-performance concrete (HPC) was analyzed in the article. In the paper, the behavior of HPC with coarse recycled aggregate and natural coarse aggregate (NCA) was compared. Short-term experiments were conducted, including concrete deformation, deflection, load bearing capacity, and cracking of beams. The analysis involved reinforced concrete T-beams made in 100% of RCA or NCA. The studies indicated that the beams with recycled aggregate are characterized by greater deflection and 7.6% lower load bearing capacity in comparison to the beams with NCA. Substitution of coarse natural aggregate with RCA reduced the compressive and tensile strengths by 20 and 26 (%), whereas and the modulus of elasticity was decreased by 15%.

scholarly journals Thin-walled profiles and their joint assembly units built with screws: numerical studies of load bearing capacity

2018 ◽  
Vol 196 ◽  
pp. 01008 ◽  
Author(s):  
Vadim Alpatov ◽  
Alexey Soloviev
Keyword(s):  
Bearing Capacity ◽  
Three Dimensional ◽  
Load Bearing Capacity ◽  
Thread Cutting ◽  
Load Bearing ◽  
Thin Walled Structures ◽  
Numerical Studies ◽  
Thin Walled ◽  
With Screws ◽  
Joint Assembly

There is a tendency to reduce weight of load-bearing metal structures being developed and successfully realized in modern building construction. This idea serves as a basis for a whole scientific direction, named Development and application of light steel thin-walled structures (LSTS). Among them, LTST built with pop-rivets and thread-cutting screws are most widespread due to their simplicity and relative cheapness This paper presents numerical studies of LSTS joint assembly units built with screws and their load bearing capacity. The peculiarity of these units consists in misalignment of joint elements. The calculation was performed in the SolidWorks Simulation System. The modeled node is a three-dimensional assembly consisting of solid components. The results of the study are as follows: 1) thin-walled profiles have a significant sensitivity to eccentricity; 2) it is unacceptable to disregard eccentricities for thin-walled profiles and their joint connections; 3) eccentricities should be compensated by measures to improve reliability in joint connections design.

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