scholarly journals INTERACTION DIAGRAMS AXIAL FORCE-BENDING MOMENT FOR FIRE EXPOSED STEEL-CONCRETE COMPOSITE SECTIONS

2016 ◽  
Author(s):  
Milivoje Milanovic ◽  
Meri Cvetkovska
Keyword(s):  
Bearing Capacity ◽  
Cross Section ◽  
Axial Force ◽  
Bending Moment ◽  
Cross Sectional ◽  
Load Bearing ◽  
Composite Columns ◽  
Interaction Diagram ◽  
Steel Sections ◽  
The Cross

The bearing capacity of the column cross section can be determined from the interaction diagram moment-axial force (M–N). Fire induced temperatures cause reduction of the load-bearing characteristics of the constitutive materials, steel and concrete, and this effect directly reflects on the reduction of the axial force and the bending moment that could be accepted by the column cross section, respectively the interaction diagram of the column cross section is changed. The load bearing capacity of the steel-concrete composite columns exposed to fire from all four sides and loaded by axial force and uni-axial or bi-axial bending moments, was estimated on the basis of the changes in the interaction diagrams moment-axial force amd the results are presented in this paper. Different types of composite columns made of totally or partially encased steel sections, or concrete filled hollow sections were analyzed and a detailed discussion on the effects of the shape of the cross section and the cross sectional dimensions are presented.

scholarly journals Cross-Sectional Analysis of the Resistance of Rc Members Subjected to Bending With/without Axial Force

2021 ◽  
Author(s):  
Marek Lechman
Keyword(s):  
Cross Section ◽  
Axial Force ◽  
Rectangular Cross Section ◽  
Bending Moment ◽  
Equilibrium Equations ◽  
Cross Sectional ◽  
Cross Sectional Analysis ◽  
Nonlinear Stress ◽  
The Cross ◽  
Sectional Analysis

The paper presents section models for analysis of the resistance of RC members subjected to bending moment with or without axial force. To determine the section resistance the nonlinear stress-strain relationship for concrete in compression is assumed, taking into account the concrete softening. It adequately describes the behavior of RC members up to failure. For the reinforcing steel linear elastic-ideal plastic model is applied. For the ring cross-section subjected to bending with axial force the normalized resistances are derived in the analytical form by integrating the cross-sectional equilibrium equations. They are presented in the form of interaction diagrams and compared with the results obtained by testing conducted on RC columns under eccentric compression. Furthermore, the ultimate normalized bending moment has been derived for the rectangular cross-section subjected to bending without axial force. It was applied in the cross-sectional analysis of steel and concrete composite beams, named BH beams, consisting of the RC rectangular core placed inside a reversed TT welded profile. The comparisons made indicated good agreements between the proposed section models and experimental results.

scholarly journals Non-linear Analysis of Slender High Strength Concrete Column

2019 ◽  
Vol 5 (7) ◽  
pp. 1440-1451
Author(s):  
Ernesto Fenollosa ◽  
Iván Cabrera ◽  
Verónica Llopis ◽  
Adolfo Alonso
Keyword(s):  
Bearing Capacity ◽  
Cross Section ◽  
Axial Force ◽  
High Strength Concrete ◽  
Bending Moment ◽  
High Strength ◽  
Concrete Columns ◽  
Strength Concrete ◽  
The Moment ◽  
High Strength Concrete Columns

This article shows the influence of axial force eccentricity on high strength concrete columns design. The behavior of columns made of normal, middle and high strength concrete with slenderness values between 20 and 60 under an eccentric axial force has been studied. Structural analysis has been developed by means of software which considers both geometrical and mechanical non-linearity. The sequence of points defined by increasing values of axial force and bending moment produced by eccentricity has been represented on the cross-section interaction diagram until failure for each tested column. Then, diagrams depicting the relationship between failure axial force and column's slenderness have been drawn. The loss of bearing capacity of the member for normal and middle strength columns when compared with the bearing capacity of their cross-section is more noticeable as axial force eccentricity assumes higher values. However, this situation reverses for high strength columns with high slenderness values. On the basis of results obtained, the accuracy level for the moment magnifier method was checked. Despite the good concordance in most of the cases, it was verified that the moment magnifier method leads to excessively tight results for high strength concrete columns with high slenderness values. In these specific cases, a coefficient which amends the column rigidity is proposed so as to obtain safer values.

scholarly journals Numerical modelling of the bearing capacity of a beam cross-section

2021 ◽  
Vol 1208 (1) ◽  
pp. 012043
Author(s):  
Besim Demirović ◽  
Rašid Hadžović ◽  
Nedim Osmić
Keyword(s):  
Numerical Modelling ◽  
Bearing Capacity ◽  
Cross Section ◽  
Cross Sections ◽  
Nonlinear Behavior ◽  
Load Bearing Capacity ◽  
Cross Sectional ◽  
Linear And Nonlinear ◽  
The Cross ◽  
Iterative Procedures

Abstract The paper presents a procedure for numerical modelling of the rod cross-section bearing capacity. Equilibrium between cross sectional forces and cross-sectional stresses is determined by iterative procedures. According to the described procedure, the load-bearing capacity of the cross-section is determined according to the isotropic linear and nonlinear behavior of the material, for homogeneous and inhomogeneous cross-sections. The nonlinear behavior of the material reduces the stiffness of the cross section of the rod EA and EI, with a significant increase in the deformation values ε and κ. The applicability of the calculation and analysis of obtained results is presented using numerical examples.

scholarly journals Springback Prediction for Pure Moment Bending of Aluminum Alloy Square Tube

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3814
Author(s):  
Stanisław Kut ◽  
Feliks Stachowicz ◽  
Grzegorz Pasowicz
Keyword(s):  
Aluminum Alloy ◽  
Cross Section ◽  
Bending Moment ◽  
Dimensional Accuracy ◽  
Experimental Tests ◽  
Cross Sectional ◽  
Cold Forming ◽  
The Cross ◽  
Springback Coefficient ◽  
Springback Prediction

The springback phenomenon occurring during cold forming is the main problem affecting the dimensional accuracy of bent products, especially when bending thin-walled profiles, where there are significant changes in the cross-section geometry. This article presents the results of the analysis of the springback phenomenon occurring during shaping with a pure bending moment of square tubes with the cross-sectional dimensions of 21.5 × 21.5 × 1.8 mm and 25 × 25 × 2.5 mm made of aluminum alloy 6060. The springback characteristics were determined by defining the dependence of the springback coefficient on the set bending radius of the band. The values of the springback coefficient were provided by means of analytical calculations and numerical modeling, which considered changes in the moment of inertia caused by deformation of the cross-section occurring during bending of the pipes. A good agreement of the calculation results with the results of experimental tests was obtained. In addition, the stress state and the state of deformation, as well as the springback characteristics of square-section pipes were compared with the results obtained during bending of a solid bar with the cross-sectional dimensions of 21.5 × 21.5 mm.

scholarly journals Cross-Section Deformation and Bending Moment of a Steel Square Tubular Section

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5170
Author(s):  
Stanisław Kut ◽  
Feliks Stachowicz
Keyword(s):  
Numerical Modeling ◽  
Cross Section ◽  
Circular Cross Section ◽  
Bending Moment ◽  
Experimental Tests ◽  
Cross Sectional ◽  
Cold Bending ◽  
Bending Process ◽  
The Cross ◽  
Sectional Shape

When bending thin-walled profiles, significant distortion of the cross-section occurs, which has a significant impact on the course of the bending moment characteristics and on the value of allowable bending curvatures. This paper presents the results of experimental and numerical modeling of the box profile bending process, which was carried out in order to determine the dependence of the cross-sectional shape and bending moment of bending curvature. Extensive numerical calculations were used to model the process of shaping a square pipe from a circular tube and to model the bending process, especially when taking into account the effects of such a deformation path. The pure bending moment characteristics and the deformation of the cross-section were performed for a 25 × 25 × 2 mm square tube made of S235JR structural steel. The innovative approach for determining the parameters of cold bending square tubes pertained to considering the stress state in the preserved material in individual areas of their cross-section. The results of numerical modeling—after considering the history of deformation (i.e., the process of forming a square pipe from a pipe with a circular cross-section)—gave a satisfactory agreement with the results of experimental tests, both in terms of the degree of pipe wall deflection and the characteristics of the bending moment.

scholarly journals Concrete-filled round-ended steel tubular stub columns under concentric and eccentric loads

2018 ◽  
Author(s):  
Ana Piquer Vicent ◽  
David Hernández-Figueirido ◽  
Carmen Ibáñez Usach
Keyword(s):  
Bearing Capacity ◽  
Mechanical Behaviour ◽  
Mechanical Response ◽  
Concrete Strength ◽  
High Strength ◽  
Load Bearing Capacity ◽  
Cross Sectional ◽  
Load Bearing ◽  
Composite Columns ◽  
Stub Columns

In the past, many works to study the mechanical behaviour of concrete filled steel tubular (CFST) stub columns have been conducted. Some of the applications of these composite columns oblige to meet higher requirements of ductility and load-bearing capacity. Traditionally, circular and rectangular tubes have been employed but recently new cross-sectional shapes of these composite columns are being designed and investigated with the aim of optimizing their mechanical behaviour. In this line, concrete-filled round-ended steel tubular columns (CFRT) have appeared as an alternative. However, the number of experimental programs to characterize their mechanical response is still scarce. In order to contribute to the test results database, in this paper an experimental study of 9 concrete-filled round-ended steel tubular stub columns is presented. All the specimens were designed with the same cross-sectional round-ended shape and have the same dimensions. In this program, both normal and high-strength concrete were employed as infill. During the tests, the columns were subjected to axial compression loads but under different eccentricities. The influence of eccentricity and concrete strength on the ultimate load bearing capacity of the concrete-filled round-ended steel tubular are discussed. Besides, the combined action of both components in this type of concrete-filled tubes as well as the effect of the concrete infill are studied.

scholarly journals ДО ВИЗНАЧЕННЯ УРІВНОВАЖУВАЛЬНОЇ НАВАНТАГИ НА ШПАНГОУТ ОДНОПАЛУБНОГО ФЮЗЕЛЯЖУ

2021 ◽  
pp. 113-121
Author(s):  
А. Г. Дибир ◽  
А. А. Кирпикин ◽  
Н. И. Пекельный
Keyword(s):  
Cross Section ◽  
Cross Sectional Area ◽  
Torsional Stiffness ◽  
Vertical Position ◽  
Sectional Area ◽  
Cross Sectional ◽  
Optimal Position ◽  
Load Bearing ◽  
The Cross ◽  
Fuselage Skin

With the optimal design of the fuselage, a very important issue is the choice of the optimal position of the load-bearing floor in the cross-section of the fuselage.Depending on the relative position of the load-bearing floor, the reduced thickness of the floor, the scheme of fastening the floor to the frames and the ratio of the reduced thicknesses of the fuselage skin and the floor, the position of the center of stiffness of the fuselage cross-section changes, the torsional stiffness of the fuselage. This leads to a change in torque, a redistribution of shear flows, a redistribution of flattening loads on the frame from the bending of the fuselage.In this work, two schemes of fastening the floor to the frame are considered - a rigid, torque connection and a hinged one. In this case, the frame takes up additional load from the floor. The fuselage is considered as a thin-walled rod, loaded with horizontal and vertical shear forces, torque and flattening forces from the fuselage bending.For reliability, the calculation of the position of the center of stiffness in a double-closed cross-section was carried out by two methods: a fictitious force and a fictitious moment. The influence of various parameters on the location of the center of rigidity was investigated. The influence of the vertical position of the floor, the ratio of the reduced thicknesses of the floor and the fuselage skin and the cross-sectional area of the beams of the floor attachment to the fuselage on the position of the center of stiffness was evaluated. Diagrams of these dependencies were constructed based on the results of calculations. The dependence of the torsional stiffness on the position of the floor and the ratio of the reduced thicknesses of the floor and the fuselage skin was investigated. Based on the calculation results, a diagram of these dependencies was built. Various constructive solutions were considered for fastening the floor to the fuselage skin: with their direct connection and with the floor support only on the beam. The floor loading from flattening loads caused by the bending of the fuselage was studied. The diagram of the loading of the frame and the floor from flattening loads is shown.According to the diagrams, you can choose the optimal vertical position of the floor, the reduced floor thickness and the cross-sectional area of the beam

STRENGTH OF CLT PANELS BY SHEAR AND TORSION

2020 ◽  
pp. 315-322
Author(s):  
Andrii Bidakov ◽  
◽  
Oksana Pustovoitova ◽  
Ievgenii Raspopov ◽  
Bogdan Strashko ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Cross Section ◽  
Experimental Studies ◽  
Load Bearing Capacity ◽  
Rolling Shear ◽  
Torsional Strength ◽  
Load Bearing ◽  
Factors Of Influence ◽  
Main Factors ◽  
The Cross

Urgency of the research. Positive experience with the use of CLT panels in distress has been observed for a long time in Eastern Europe and is considered necessary to study the strength and factors affecting the load-bearing capacity of this type of structures made of transverse glued wood (CLT). Target setting. An integral important issue for CLT panels is torsional strength, which has a scheme of destruction by chipping layers of boards and requires the establishment of the main factors of influence to assess the load-bearing capacity of this type of stress. Actual scientific researches and issues analysis. Shear and torsional strength is one of the main issues in the strength of CLT panels as an orthotropic plate, which has interested many researchers from different countries, including Blaß, Görlacher (2002) [1], Bosl (2002) [4], Jeitler (2004) [11 ], Jöbstl, Bogensperger, Schieckhofer [12], Wallner (2004) [18], Bogensperger, Moosbrugger (2007) [3], Silly (2010) [14, 15], Hirschmann (2011), Blaß, Flaig (2012) [2], Dröscher, Brandner, Kreuzinger, Sieder (2013), Dietsch (2017), Serrano (2018). Uninvestigated parts of general matters defining. The issue of identifying factors influencing the bearing capacity of PKD panels during shear and torsion has not been resolved.. The purpose of the article. Establishment of the main factors of influence for an estimation of bearing capacity of CLT of panels at shift and torsion.. The presentation of the main material. Cross laminated timber, as a sheet building material based on layers of boards with mutually perpendicular arrangement of boards in adjacent layers, has a number of important factors that affect the strength of CLT panels in shear and torsion. Thirty years of world experience in the use of CLT panels in multi-storey construction proves the importance of considering different models of panels as diaphragms and rigid frame elements from panel-frame buildings. Particular attention is paid to the nature of the destruction of the panel for chipping, both in the plane of the panel and from the plane. The importance of this type of stress state is further enhanced by a group of different shear or group of test schemes according to EN16351, including rolling shear strength tests. The latter value of strength is a new phenomenological feature of CLT panels. Conclusions and suggestion. Based on experimental studies of the strength of the glued rods in the cross section of CLT panel, the change in strength depending on the diameter of the metal rod and its location in the cross section, which is characterized by alternation of mutually transverse layers of boards.

Reliability Calculation of RC Monopod Structures Under Extreme Wave Loading

2006 ◽  
Author(s):  
H. Karadeniz
Keyword(s):  
Cross Section ◽  
Axial Force ◽  
Bending Moment ◽  
Wave Loading ◽  
Compression Zone ◽  
Reliability Calculation ◽  
Eurocode 2 ◽  
Strain Stress ◽  
The Cross ◽  
Stress Relation

In this paper, a general formulation of section-capacities of a circular RC tubular cross-section is first presented. It is assumed that the strain-stress relation of the concrete in the compression zone is simply modelled as bilinear function with ultimate values given in Eurocode 2, and the concrete works only in the compression zone. Tension stresses of the cross-section are carried by the reinforcement. Having presented a general formulation of extreme bending moment and axial force of a RC monopod offshore tower under wave loading, uncertainties in both section capacities and loading terms are presented. Then, a reliability calculation of the cross-section is performed. In this calculation, the balance of the axial force is used to determine concrete compression zone during the reliability iteration and the failure function is defined on the basis of the section capacity- and applied bending moments. Variation of the reliability index with various parameters is investigated and most sensitive uncertainty variables are identified.

Automated Diagonal Slice and View Solution for 3D Device Structure Analysis

2018 ◽  
Author(s):  
Sang Hoon Lee ◽  
Jeff Blackwood ◽  
Stacey Stone ◽  
Michael Schmidt ◽  
Mark Williamson ◽  
...  
Keyword(s):  
Cross Section ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Image Data ◽  
Planar Surface ◽  
Device Structure ◽  
Cross Sectional ◽  
Device Structures ◽  
The Cross ◽  
Planar Analysis

Abstract The cross-sectional and planar analysis of current generation 3D device structures can be analyzed using a single Focused Ion Beam (FIB) mill. This is achieved using a diagonal milling technique that exposes a multilayer planar surface as well as the cross-section. this provides image data allowing for an efficient method to monitor the fabrication process and find device design errors. This process saves tremendous sample-to-data time, decreasing it from days to hours while still providing precise defect and structure data.

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