scholarly journals Validation of the load-bearing capacity of the frame assembly of metal structures on the standard 2.440 series using IDEA StatiCa

2020 ◽  
Vol 10 (3) ◽  
pp. 406-419
Author(s):  
Denis A. Melnikov ◽  
◽  
Tatyana L. Dmitrieva ◽  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Cross Sections ◽  
Limit State ◽  
Local Buckling ◽  
High Strength ◽  
Software Systems ◽  
Rigid Frame ◽  
Welding Forces ◽  
Element Method

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.

The Accepting of Pipe Bends With Ovality and Thinning Using Finite Element Method

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
AR. Veerappan ◽  
S. Shanmugam ◽  
S. Soundrapandian
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Internal Pressure ◽  
Cross Sections ◽  
Pressure Ratio ◽  
Empirical Relationship ◽  
The Finite Element Method ◽  
Element Method

Thinning and ovality are commonly observed irregularities in pipe bends, which induce higher stress than perfectly circular cross sections. In this work, the stresses introduced in pipe bends with different ovalities and thinning for a particular internal pressure are calculated using the finite element method. The constant allowable pressure ratio for different ovalities and thinning is presented at different bend radii. The allowable pressure ratio increases, attains a maximum, and then decreases as the values of ovality and thinning are increased. An empirical relationship to determine the allowable pressure in terms of bend ratio, pipe ratio, percent thinning, and percent ovality is presented. The pipe ratio has a strong effect on the allowable pressure.

scholarly journals DEVELOPMENT OF THE METAL RHEOLOGY MODEL OF HIGH-TEMPERATURE DEFORMATION FOR MODELING BY FINITE ELEMENT METHOD

2019 ◽  
Vol 2 ◽  
pp. 52-60 ◽  
Author(s):  
Oleg Markov ◽  
Oleksiy Gerasimenko ◽  
Leila Aliieva ◽  
Alexander Shapoval
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress Relaxation ◽  
Hot Deformation ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Software Systems ◽  
Elastic Model ◽  
Communication Model ◽  
Element Method

It is shown that when modeling the processes of forging and stamping, it is necessary to take into account not only the hardening of the material, but also softening, which occurs during hot processing. Otherwise, the power parameters of the deformation processes are precisely determined, which leads to the choice of more powerful equipment. Softening accounting (processes of stress relaxation) will allow to accurately determine the stress and strain state (SSS) of the workpiece, as well as the power parameters of the processes of deformation. This will expand the technological capabilities of these processes. Existing commercial software systems for modeling hot plastic deformations based on the finite element method (FEM) do not allow this. This is due to the absence in these software products of the communication model of the component deformation rates and stresses, which would take into account stress relaxation. As a result, on the basis of the Maxwell visco-elastic model, a relationship is established between deformation rates and stresses. The developed model allows to take into account the metal softening during a pause after hot deformation. The resulting mathematical model is tested by experiment on different steels at different temperatures of deformation. The process of steels softening is determined using plastometers. It is established experimentally that the model developed by 89 ... 93 % describes the rheology of the metal during hot deformation. The relationship between the components of the deformation rates and stresses is established, which allows to obtain a direct numerical solution of plastic deformation problems without FED iterative procedures, taking into account the real properties of the metal during deformation. As a result, the number of iterations and calculations has significantly decreased.

Finite Element Method and Analytical Studies on Fiber-Metal Laminates under Multiaxial Loadings

2017 ◽  
Vol 23 ◽  
pp. 63-71
Author(s):  
David J. Kvam ◽  
Yi Yu Duan ◽  
Erica Donnelly ◽  
Alicia Restrepo
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
High Strength ◽  
Finite Element Method Simulation ◽  
Fiber Metal Laminates ◽  
Composites Materials ◽  
Laminate Theory ◽  
Fiber Metal ◽  
High Strength Fiber ◽  
Element Method

Fiber-metal laminates (FMLs) are composites materials that are commonly used in areas such as aircraft industry. They are composed of ductile metal layers with high strength fiber reinforced polymer layers. So far, however, only uniaxial tests have been used to characterize the quasistatic mechanical properties, which cannot reflect the real loading situation of the FML applications. In this work biaxial tensile behavior of FMLs with glass and Kevlar fibers based on aluminum alloy is studied with finite element method simulation. The simulation is run to find the stress-strain relationship for FMLs at the off-axis angles of 0˚ and 45˚ for glass and Kevlar fibers. The “composites layups” are constructed for the 3D FML part. Two different elements C3D8R (8-node linear) and C3D20R (20-node quadratic) are used to carry out the simulation. The results show that C3D20R shows major advantages. Analytical solutions based on the classical laminate theory are obtained to compare with the finite element method (FEM) solutions. The results show good consistency.

Analysis of beams with piezo-patches by node-dependent kinematic finite element method models

2017 ◽  
Vol 29 (7) ◽  
pp. 1379-1393 ◽  
Author(s):  
Erasmo Carrera ◽  
Enrico Zappino ◽  
Guohong Li
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Cross Sections ◽  
Constitutive Relations ◽  
Three Dimensional ◽  
Single Layer ◽  
Present Contribution ◽  
Stiffness Matrices ◽  
Carrera Unified Formulation ◽  
Element Method

This article presents a family of one-dimensional finite element method models with node-dependent kinematics for the analysis of beam structures with piezo-patches. The models proposed are built by applying Carrera unified formulation. Carrera unified formulation permits to obtain finite element method stiffness matrices through so-called fundamental nuclei whose form is independent of the assumptions made for the displacement/electrical field over the cross section of a beam. In the previous works, uniform kinematic assumptions have been applied to all the nodes within the same element. The present contribution proposes to use different kinematics on different nodes, leading to node-dependent kinematic finite element method formulations. In such an approach, non-uniform cross sections introduced by piezo-patches can be considered. With the help of layer-wise models, piezoelectric and mechanical domains each can possess individual constitutive relations. Meanwhile, node-dependent kinematics can integrate equivalent single layer models and layer-wise models to reach an optimal balance between accuracy and use of computational resources. Static governing equations for beam elements with node-dependent kinematics accounting for electromechanical effects are derived from the principle of virtual displacements. The competence of the proposed approach is validated by comparing the obtained results with solutions taken from the literature and ABAQUS three-dimensional modelling. Both extension and shear actuation mechanisms are considered.

Analysis of the galloping behaviour of an electrified railway overhead contact line using the non-linear finite element method

2018 ◽  
Vol 232 (10) ◽  
pp. 2339-2352 ◽  
Author(s):  
Yang Song ◽  
Zhigang Liu ◽  
Hongrui Wang ◽  
Jing Zhang ◽  
Xiaobing Lu ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Cross Sections ◽  
Contact Line ◽  
Aerodynamic Coefficients ◽  
Contact Wire ◽  
Linear Finite Element ◽  
Non Linear ◽  
Electrified Railway ◽  
Element Method

Galloping of an electrified railway overhead contact line (also known as catenary galloping) is a large-amplitude wind-induced vibration under extreme conditions that is extremely detrimental to the railway infrastructure. This paper attempts to conduct a numerical simulation of catenary galloping and analyse its galloping behaviour. Computational fluid dynamics is utilized to calculate the aerodynamic coefficients of the contact wire with different classes of wear. The mechanism of catenary galloping is revealed by the Den Hartog theory. To describe the non-linear behaviour of catenary galloping, a non-linear finite element method is employed to establish the catenary model, which properly considers the geometrical non-linearity of the contact/messenger wire and the non-smooth non-linearity of droppers. Considering the effect of fluid-induced vibration, the self-excited forces acting on the contact wire are derived. Through several numerical examples, the galloping responses of the catenary are analysed with different tension classes and stochastic wind. The results demonstrate that the extreme wear of the contact wire caused by the long-term passage of pantograph can change the aerodynamic coefficients of the cross-sections of the contact wire and cause the system’s instability under steady wind load. It is concluded that upgrading the catenary tension class can effectively suppress catenary galloping. The stochastic wind only has small effect on the catenary galloping. The stochastic wind only has small effect on the catenary galloping.

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
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
High Strength ◽  
Experimental Tests ◽  
Analytical Models ◽  
End Plate ◽  
Plate Connections ◽  
Plate Connection ◽  
Element Method

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.

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