scholarly journals Verification of prying effect in prestressed end-plate connection

2013 ◽  
Vol 12 (2) ◽  
pp. 251-258
Author(s):  
Krzysztof Ostrowski ◽  
Jan Łaguna ◽  
Aleksander Kozłowski

End-plate connections are very often used is steelwork, as tension and bending connections. As a result of deflection of end plate, additional forces, known as prying forces arise and consequently increase stresses in bolts. Eurocode 1993-1-8 do not distinguish end-plate connections prestressed by high strength bolts from non-prestressed. The aim of the paper is to perform the comparison of previous analytical models and code regulations for coefficient of prying forces to the experimental tests and modelling by finite element method. Results of the analysis show that the behaviour of prestressed connection is essentially different with comparison to non-prestressed.

2012 ◽  
Vol 446-449 ◽  
pp. 867-870
Author(s):  
Hong Wei Liu ◽  
Jun Li

Steel portal frame is easy to build,but the connection styles of end-plate have greater influence on the structure. In this paper, The formula about initial stiffness of end-plate connections has been given.The essay uses ANSYS to analyze the initial stiffness of end-plate connections. Several factors have also been analyzed about the stiffness.The conclusion is that the form of end-plate, thickness, bolt diameter all affect the structural deflections.But these reasons couldn’t change the integral moment of the structure.


Author(s):  
Denis A. Melnikov ◽  
◽  
Tatyana L. Dmitrieva ◽  

The paper aims to study the actual operation of a rigid frame unit for coupling a crossbar with a column on high-strength bolts according to the standard 2.440-2 series using modern software systems of the component finite element method. Special attention was paid to the operation of nodal elements, as well as their stress-strain state. Based on the results of static calculations, the cross-sections of the elements under consideration, as well as the components of the node (plates, bolts, seams, etc.) were selected from the tables of the standard series. Subsequently, using the component finite element method serving as the basis of the IDEA StatiСa software, all the components of the node were mod-elled with respect to acting forces. The conducted calculations confirmed the suitability of the obtained node model for identifying inconsistencies in the series and modern standards. Using stresses on plates, bolt and welding forces, as well as several forms of vibration to assess the stability of compo-nents, the applicability of the node in question in the proposed configuration was evaluated. It turned out that the node failed to meet modern standards in terms of design conditions. Moreover, the serial bolts were overloaded by almost 38%, and some welds approached the limit state. When used in real conditions, this can lead to serious losses, including human lives. Recommendations are given for changing the specific configuration of the node in order to protect it from the destruction of any nature, including local buckling failure.


Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5536
Author(s):  
David Curto-Cárdenas ◽  
Jose Calaf-Chica ◽  
Pedro Miguel Bravo Díez ◽  
Mónica Preciado Calzada ◽  
Maria-Jose Garcia-Tarrago

Cold expansion technology is an extended method used in aeronautics to increase fatigue life of holes and hence extending inspection intervals. During the cold expansion process, a mechanical mandrel is forced to pass along the hole generating compressive residual hoop stresses. The most widely accepted geometry for this mandrel is the tapered one and simpler options like balls have generally been rejected based on the non-conforming residual hoop stresses derived from their use. In this investigation a novelty process using multiple balls with incremental interference, instead of a single one, was simulated. Experimental tests were performed to validate the finite element method (FEM) models and residual hoop stresses from multiple balls simulation were compared with one ball and tapered mandrel simulations. Results showed that the use of three incremental balls significantly reduced the magnitude of non-conforming residual hoop stresses and the extension of these detrimental zone.


2014 ◽  
Vol 1025-1026 ◽  
pp. 878-884
Author(s):  
Jong Wan Hu ◽  
Jun Hyuk Ahn

This paper is principally performed to survey end-plate connection are described in the next part based on ideal limit states. The determination of end-plate based on the full plastic strength of the steel beam in accordance with 2001 AISC-LRFD manual and AISC/ANSI 358-05 Specifications. The bolted connections considered herein were performed to include the end-plate component of moment connections. This study is intended to investigate economic design for end-plate connections. In addition, the proposed end-plate model is evaluated by comparing the required factored bolt strength. The end-plates using 8 high strength bolts with wider gages demonstrated this design. The equations belonging to the step-by-step design procedure are described based on complete proving of design. Finally, new design methodology is applied to end-plate connections suggested in this study.


2019 ◽  
Vol 11 (7) ◽  
pp. 168781401985368 ◽  
Author(s):  
Jesús Acevedo-Mijangos ◽  
Antonio Ramírez-Treviño ◽  
Daniel A May-Arrioja ◽  
Patrick LiKamWa ◽  
Héctor Vázquez-Leal ◽  
...  

We present a resonant magnetic field sensor based on microelectromechanical systems technology with optical detection. The sensor has single resonator composed of two orthogonal silicon beams (600 µm × 26 µm × 2 µm) with an integrated mirror (50 µm × 34 µm × 0.11 µm) and gold tracks (16 µm × 0.11 µm). The resonator is fabricated using silicon-on-insulator wafer in a simple bulk micromachining process. The sensor has easy performance that allows its oscillation in the first bending vibration mode through the Lorentz force for monitoring in-plane magnetic field. Analytical models are developed to predict first bending resonant frequency, quality factor, and displacements of the resonator. In addition, finite element method models are obtained to estimate the resonator performance. The results of the proposed analytical models agree well with those of the finite element method models. For alternating electrical current of 30 mA, the sensor has a theoretical linear response, a first bending resonant frequency of 43.8 kHz, a sensitivity of 46.1 µm T−1, and a power consumption close to 54 mW. The experimental resonant frequency of the sensor is 53 kHz. The proposed sensor could be used for monitoring in-plane magnetic field without a complex signal conditioning system.


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