INFLUENCE OF THE SEMI‐RIGID BOLTED STEEL JOINTS ON THE FRAME BEHAVIOUR

2010 ◽  
Vol 16 (2) ◽  
pp. 237-241 ◽  
Author(s):  
Alfonsas Daniūnas ◽  
Kęstutis Urbonas
Keyword(s):  
Axial Force ◽  
Research Work ◽  
Bolted Joints ◽  
Main Attention ◽  
Component Method ◽  
Axial Forces ◽  
Rigid Joints ◽  
Joint Behaviour ◽  
Steel Joints

This research work describes the analysis of steel semi rigid joints that are subjected to bending and tension or compression. The main attention is focussed on the beam‐to‐beam and plate bolted joints. Usually influence of axial force is neglected. In fact, the level of tension or compression of axial force can be significant and has some impact on joint behaviour and on its stiffness and strength characteristics. Nowadays the most powerful method for the estimation of joints characteristics is the component method. The adaptation of the component method for the determination of joints characteristics under bending ant axial forces is shown in the paper. Some numerical results of calculations of steel frameworks are presented in this paper as well (Daniūnas and Urbonas 2008). Santrauka Straipsnyje nagrinejami pusiau standūs mazgai, veikiami lenkiamojo momento ir tempimo ar gniuždymo ašines jegos. Daugiausia demesio skiriama sijos, sujungtos varžtais per galines plokšteles su kita sija, mazgui. Dažniausiai teigiama, kad ašines jegos itaka mazgo elgsenai yra nereikšminga. Iš tikruju gniuždymo ar tempimo ašines jegos dydis gali būti reikšmingas ir daryti svaria itaka mazgo elgsenai, sukamojo standžio ir lenkiamosios galios reikšmems. Populiariausias ir plačiausiai šiuo metu taikomas metodas mazgo charakteristikoms nustatyti yra komponentu metodas. Šiame straipsnyje rodoma, kaip taikomas komponentu metodas nustatyti mazgo, veikiamo lenkiamojo momento ir ašines jegos, charakteristikoms. Pateikiami ir plieniniu reminiu konstrukciju skaičiavimu rezultatai (Daniūnas, Urbonas 2008).

scholarly journals COMPONENT METHOD EXTENSION TO STEEL BEAM‐TO‐BEAM AND BEAM‐TO‐COLUMN KNEE JOINTS UNDER BENDING AND AXIAL FORCES

2005 ◽  
Vol 11 (3) ◽  
pp. 217-224 ◽  
Author(s):  
Kestutis Urbonas ◽  
Alfonsas Daniūnas
Keyword(s):  
Axial Force ◽  
Bending Moment ◽  
Practical Method ◽  
Knee Joints ◽  
Steel Beam ◽  
Component Method ◽  
End Plate ◽  
Axial Forces ◽  
Joint Rigidity

This paper presents an analysis of semi‐rigid beam‐to‐beam end‐plate bolted and beam‐to‐column end‐plate bolted knee joints that are subjected to bending and tension or compression axial force. Usually the influence of axial force on joint rigidity is neglected. According to EC3, the axial load, which is less than 10 % of plastic resistance of the connected member under axial force, may be disregarded in the design of joint. Actually the level of axial forces in joints of structures may be significant and has a significant influence on joint rigidity. One of the most popular practical method permitting the determination of rigidity and strength of joint is the so‐called component method. The extension of the component method for evaluating the influence of bending moment and axial force on the rigidity and strength of the joint are presented in the paper. The numerical results of calculations of rigidity and strength of beam-to-beam and beam-to-column knee joints are presented in this paper as well.

Preliminary Parametric Assessment of a Bolted Endplate Joint under Combined Axial Force and Cyclic Bending Moment

2011 ◽  
Vol 255-260 ◽  
pp. 718-721
Author(s):  
Z.Y. Wang ◽  
Q.Y. Wang
Keyword(s):  
Finite Element Analysis ◽  
Axial Force ◽  
Seismic Design ◽  
Axial Load ◽  
Failure Modes ◽  
Bending Moment ◽  
Element Analysis ◽  
Cyclic Behaviour ◽  
Joint Behaviour ◽  
Steel Joints

Problems regarding the combined axial force and bending moment for the behaviour of semi-rigid steel joints under service loading have been recognized in recent studies. As an extended research on the cyclic behaviour of a bolted endplate joint, this study is performed relating to the contribution of column axial force on the cyclic behaviour of the joint. Using finite element analysis, the deteriorations of the joint performance have been evaluated. The preliminary parametric study of the joint is conducted with the consideration of flexibility of the column flange. The column axial force was observed to significantly influence the joint behaviour when the bending of the column flange dominates the failure modes. The reductions of moment resistance predicted by numerical analysis have been compared with codified suggestions. Comments have been made for further consideration of the influence of column axial load in seismic design of bolted endplate joints.

scholarly journals The axial force influence on the flexibility of steel joints subject to bending under fully developed fire conditions

2014 ◽  
Vol 13 (3) ◽  
pp. 251-258
Author(s):  
Mariusz Maślak ◽  
Małgorzata Snela
Keyword(s):  
Quantitative Evaluation ◽  
Axial Force ◽  
Knee Joints ◽  
Steel Beam ◽  
Significant Modification ◽  
Calculation Algorithm ◽  
Component Method ◽  
Internal Forces ◽  
Steel Joints ◽  
Fire Conditions

The axial force qualitative influence as well as its quantitative evaluation on the behaviour of the flexible steel beam-to-beam and column-to-column knee joints subject to bending under fire conditions are assessed and discussed in detail. The proposed calculation algorithm is based on the generalization of classical component method. The essential effect of such axial force is not only the correction of internal forces applied to particular joint components, but also the significant modification of their strain conditions.

Preliminary Studies on the Determination of FLD for Single Point Incremental Sheet Metal Forming

2012 ◽  
Vol 504-506 ◽  
pp. 863-868 ◽  
Author(s):  
Miklos Tisza ◽  
Péter Zoltán Kovács ◽  
Zsolt Lukács
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
New Technologies ◽  
Single Point ◽  
Research Work ◽  
Dimensional Accuracy ◽  
Forming Limit ◽  
Incremental Sheet Metal Forming

Development of new technologies and processes for small batch and prototype production of sheet metal components has a very important role in the recent years. The reason is the quick and efficient response to the market demands. For this reasons new manufacturing concepts have to be developed in order to enable a fast and reliable production of complex components and parts without investing in special forming machines. The need for flexible forming processes has been accelerated during the last 15 years, and by these developments the technology reaches new extensions. Incremental sheet metal forming (ISMF) may be regarded as one of the promising developments for these purposes. A comprehensive research work is in progress at the University of Miskolc (Hungary) to study the effect of important process parameters with particular emphasis on the shape and dimensional accuracy of the products and particularly on the formability limitations of the process. In this paper, some results concerning the determination of forming limit diagrams for single point incremental sheet metal forming will be described.

Determination of Heat Input in Tungsten Inert Gas and Laser Welding of Type Optim 960 QC Structural Steel Using Adams’ Equation for 2-D Heat Distribution

2017 ◽  
Vol 750 ◽  
pp. 45-52
Author(s):  
Sveto Cvetkovski
Keyword(s):  
Laser Welding ◽  
Heat Input ◽  
Arc Welding ◽  
Research Work ◽  
Laser Beam Welding ◽  
Peak Temperature ◽  
Efficiency Coefficient ◽  
Zone Recrystallization ◽  
Welding Processes

The heat input during conventional arc welding processes can be readily calculated knowing the power taken from the power source. The efficiency coefficient can be taken from the appropriate literature standards. Here, the intention of the performed research work was to develop a procedure for determination of heat input in arc and laser welding processes implementing Adams equation - modified Rykalin equation for two dimensional heat distributions (2-D). To realize this idea, it is necessary to determine two characteristic temperatures points in the HAZ with known peak temperature, and to determine distance between them. Implementing measured values for distance in Adams’ equation, heat input in arc welding can be directly determined in arc welded joints.In laser beam welding, the absorption of the beam in the metal is not known, so that the welding heat input cannot be calculated directly, and direct implementation of Adam’s equation is not possible i.e. absorption coefficient has to be determined first, and after that calculation of heat input is possible.The peak temperatures corresponding to specific microstructures can be obtained by performing welding simulation, by the Gleeble 1500 simulator in our case. As one of the peak temperatures, the melting temperature can be used corresponding to the fusion line, so that at least one characteristic peak temperature such as coarse grain zone, fine grin zone, intercritical zone, recrystallization, has to be determined by the simulation.Performed research showed that obtained values for heat input using Adam’s equation correspond pretty well with standard equation for heat input in arc welding.

Analysis of Aluminium Beam-to-Column Joints by the Component Method: Existing Studies and Research Needs

2016 ◽  
Vol 710 ◽  
pp. 409-414 ◽  
Author(s):  
Gianfranco De Matteis ◽  
Giuseppe Brando
Keyword(s):  
Current Knowledge ◽  
Component Method ◽  
The Past ◽  
Research Fields ◽  
Numerical Studies ◽  
Current State ◽  
Moment Resisting ◽  
New Research ◽  
Steel Joints

This paper aims at providing an overview on the current state of the art and on possible future developments concerning the component method implementation for the classification of beam-to-column joints belonging to aluminum moment resisting frames.After a brief discussion on the component method theoretical bases, developed in the past to give a feasible calculation procedure for steel joints, recent experimental and numerical studies, carried out for investigating some aluminum components, are presented and discussed. In particular strengths and weaknesses of the current knowledge are put into evidence, also in light of the peculiarities that make aluminum alloys different from steel. The launch of new research fields, aimed at pursuing an update of the current codes dealing with aluminum structures, is therefore proposed.

A New Approach for Determining Joint Stiffness of Bolted Joints

2014 ◽  
Vol 670-671 ◽  
pp. 1041-1044 ◽  
Author(s):  
Xi Wang Wang ◽  
Xiao Yang Li ◽  
Lin Lin Zhang ◽  
Xiao Guang Wang
Keyword(s):  
Accurate Determination ◽  
Joint Stiffness ◽  
Fatigue Loading ◽  
Bolted Joints ◽  
Analytical Models ◽  
Bolted Connection ◽  
New Approach ◽  
Axisymmetric Model ◽  
Force Equilibrium

Joint member stiffness in a bolted connection directly influence the safety of a design in regard to both static and fatigue loading as well as in the prevention of separation in the connection. Thus, the accurate determination of the stiffness is of extreme importance to predict the behavior of bolted assemblies. In this paper, An analytical 3D axisymmetric model of bolted joints is proposed to obtain the joint stiffness of Bolted Joints. Considering many different analytical models have been proposed to calculate the joint stiffness, the expression based force equilibrium can be a easy way to choose the best expression for the joint stiffness as a judgment criteria.

Determination of the minimum suppressive concentration of photosensitizers of the second generation in relation to sanitaryindicative microorganisms

2021 ◽  
Vol 1 (11) ◽  
pp. 42-46
Author(s):  
Vadim Yu. Shlenskiy ◽  
◽  
Tatiana I. Pashnik ◽  
Svetlana Yu. Pigina ◽  
◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Salmonella Enteritidis ◽  
Second Generation ◽  
Research Work ◽  
Protoporphyrin Ix ◽  
Bactericidal Effect ◽  
Disodium Salt ◽  
Bacterial Cultures

In the studies described in the article, the presence of antimicrobial activity in photosensitizers in experiments on bacterial cultures was confirmed. In the experiments, photosensitizers of the second generation were used: «Photoditazine», the active substance of which is dimeglumin chloride E6, and «Dimegin», which includes a derivative of protoporphyrin IX-2,4-di(1-methoxyethyl)- deuteroporphyrin IX disodium salt. In the described research work, the minimum concentrations of the studied drugs were determined by the method of sequential tenfold dilutions to obtain a bactericidal effect on strains of sanitary-indicative microorganisms Enterococcus faecalis, Staphylococcus aureus, Salmonella enteritidis.

Advances In The Modeling And Dynamic Simulation of Reeving Systems Using The Arbitrary Lagrangian-Eulerian Modal Method

2021 ◽  
Author(s):  
José L. Escalona ◽  
Narges Mohammadi
Keyword(s):  
Finite Elements ◽  
Axial Force ◽  
Axial Direction ◽  
Rotary Inertia ◽  
Arbitrary Lagrangian Eulerian ◽  
Original Formulation ◽  
Absolute Position ◽  
Axial Forces ◽  
Modal Coordinates ◽  
Modal Method

Abstract This paper presents new advances in the arbitrary Lagrangian-Eulerian modal method (ALEM) recently developed for the systematic simulation of the dynamics of general reeving systems. These advances are related to a more convenient model of the sheaves dynamics and the use of axial deformation modes to account for non-constant axial forces within the finite elements. Regarding the sheaves dynamics, the original formulation uses kinematic constraints to account for the torque transmission at the sheaves by neglecting the rotary inertia. One of the advances described in this paper is the use of the rotation angles of the sheaves as generalized coordinates together with the rope-to-sheave no-slip assumption as linear constraint equations. This modeling option guarantees the exact torque balance the sheave without including any non-linear kinematic constraint. Numerical results show the influence in the system dynamics of the sheave rotary inertia. Regarding the axial forces within the finite elements, the original formulation uses a combination of absolute position coordinates and transverse local modal coordinates to account for the rope absolute position and deformation shape. The axial force, which only depends on the absolute position coordinates, is constant along the element because linear shape functions are assumed to describe the axial displacements. For reeving systems with very long rope spans, as the elevators of high buildings, the constant axial force is inaccurate because the weight of the ropes becomes important and the axial force varies approximately linearly within the rope free span. To account for space-varying axial forces, this paper also introduces modal coordinates in the axial direction. Numerical results show that a set of three modal coordinates in the axial direction is enough to simulate linearly varying axial forces.

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