scholarly journals The Influence of Symmetrical Boundary Conditions on the Structural Behaviour of Sandwich Panels Subjected to Torsion

Symmetry ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2093 ◽  
Author(s):  
Zbigniew Pozorski ◽  
Szymon Wojciechowski
Keyword(s):  
Boundary Conditions ◽  
Numerical Models ◽  
Sandwich Panels ◽  
Structural Response ◽  
Numerical Results ◽  
Beam Model ◽  
Structural Behaviour ◽  
High Agreement ◽  
Various Boundary Conditions ◽  
Support Conditions

The paper discusses the influence of load and support conditions on the behaviour of sandwich panels subjected to torsion. 3-D numerical models are presented, in which various boundary conditions have been defined. The case of the load causing the concentrated torque in the span is analyzed, and the load definition affects the structural response. The numerical results were compared with the results obtained for the analytical beam model, which included both free torsion and secondary warping torsion. The conditions under which the models achieve a high agreement between the results were determined, but the significant sensitivity of the solution was also indicated. In each case of the considered load and boundary conditions, the structural response shows appropriate symmetry.

scholarly journals Influence of boundary conditions in FEM model on structural behaviour of thin-walled steel beams strengthened by CFRP tapes

2020 ◽  
Vol 19 (2) ◽  
pp. 073-086
Author(s):  
Katarzyna Rzeszut ◽  
Ilona Szewczak ◽  
Patryk Rozylo
Keyword(s):  
Boundary Conditions ◽  
Laboratory Tests ◽  
Numerical Models ◽  
Load Capacity ◽  
Steel Beams ◽  
Structural Behaviour ◽  
Fem Model ◽  
Mesh Density ◽  
Newton Raphson ◽  
Thin Walled

The main aim of the study is verification and validation of FEM numerical model of beams made of thin-walled steel profiles retrofitted by CFRP tapes Sika CarboDur S. Validation is are carried out based on own laboratory tests conducted on “Blachy Pruszyński” S-type beams. The CFRP tape are bonded to the beam at compressed or tensioned flange. The most important part of this study is focused on investigation of boundary conditions influence in FEM model developed in Abaqus program. Moreover the numerical models are also tested in terms of different mesh density and types of finite elements. Numerical analyses are carried out using Newton-Raphson iterative method to solve non-linear equilibrium equation. In the paper special attention is paid to the evaluation of the possibility to increase the load capacity of the beams by appropriate localisation of CFRP tape.

On the Bolotin's reduced beam model versus various boundary conditions

2020 ◽  
Vol 105 ◽  
pp. 103505
Author(s):  
Igor I. Andrianov ◽  
Jan Awrejcewicz ◽  
Wim T. van Horssen
Keyword(s):  
Boundary Conditions ◽  
Beam Model ◽  
Various Boundary Conditions ◽  
Model Versus

Simulating Post Punching Behaviour of RC Slab-Column Connections Using a Micro Model

2016 ◽  
Vol 846 ◽  
pp. 231-236
Author(s):  
Hui Zhong Xue ◽  
Hong Guan ◽  
Xin Zheng Lu ◽  
Yi Li
Keyword(s):  
Numerical Model ◽  
Numerical Models ◽  
Progressive Collapse ◽  
Structural Response ◽  
Calibration Method ◽  
Failure Criteria ◽  
Micro Model ◽  
Structural Behaviour ◽  
Flat Plates ◽  
Rc Slab

Punching shear is a common failure mode occurring at the slab-column connection region of a reinforced concrete (RC) flat plate. Progressive collapse of RC flat plates poses a significant scientific question on the post punching behaviour of such a structural system. The challenge lies in the complex interactions amongst various internal actions including large unbalanced moments and shear forces. Existing numerical models are unable to differentiate the influence of each individual action within the connection region after punching occurs. Therefore, a new numerical model is required to model these actions individually as well as to evaluate their interrelationships. This paper thus aims to propose a numerical method to investigate the structural response of RC slab-column connections by using a micro model, based on a representative post punching failure experiment. In the micro model, concrete is simulated using solid elements whilst the reinforcement is modelled with truss elements. In this micro model, the constitutive laws and failure criteria of materials play a crucial role in describing the model’s structural behaviour. A typical structural response is discussed and a calibration method is established. Ultimately this study is expected to facilitate the development of an effective, yet simplified numerical model for future progressive collapse simulation of slab-column connections.

Vibration of a Fluid Conveying Pipe Carrying a Discrete Mass

1974 ◽  
Vol 96 (4) ◽  
pp. 268-272 ◽  
Author(s):  
T. T. Wu ◽  
P. P. Raju
Keyword(s):  
Dynamic Response ◽  
Boundary Conditions ◽  
Flow Velocity ◽  
General Expression ◽  
Normal Modes ◽  
Critical Value ◽  
Numerical Results ◽  
Simply Supported ◽  
Various Boundary Conditions ◽  
Discrete Mass

This paper presents a method to predict the dynamic response of a fluid conveying pipe carrying a discrete mass when the flow velocity is less than its critical value. A general expression for the normal modes of a vibrating pipe with various boundary conditions is newly derived herein. Also presented for a particular case are the numerical results of eigenfunctions and eigenvalues which can be used to calculate the dynamic response of a simply-supported pipe with an attached discrete mass at its mid-span.

scholarly journals Structural Response and Stochastic Impact Modeling

2018 ◽  
Vol 183 ◽  
pp. 01050
Author(s):  
Renata Troian ◽  
Manel Dallali ◽  
Didier Lemosse ◽  
Leila Khalij
Keyword(s):  
Structural Model ◽  
Numerical Models ◽  
Structural Response ◽  
Point Of View ◽  
Structural Behavior ◽  
Beam Model ◽  
Wide Range ◽  
Extreme Sensitivity ◽  
The Impact ◽  
Bernoulli Beam Model

The problem of the vulnerability of structures facing explosions came to the front line of the scientific scene in the last decades. Uncertainty of the environmental conditions and material properties have to be taken into account. The corresponding numerical models are very complex and depend on numerous parameters. Consequently, such models are cursed with issues which limit their use for real applications. Most of the existing approaches are based on a deterministic point of view, and are not able to represent the extreme sensitivity of a model towards uncertain parameters. That is why the uncertainty analysis is needed. The proposed research is devoted to the analysis of a structural behavior under an uncertain impact loading. Elasto-plastic Bernoulli beam model is used as structural model for the case simplicity, while the different formulation for impact itself are studied to simulate the wide range of possible types of impact. Model sensitivity is studied first. The influence of input parameters on structural behavior, that are the impact force, duration and position, as well as beam material are then considered. The obtained insights can provide the guidelines for modeling the structure under the explosive loading taking into account the uncertainties.

Finite element modelling of sandwich panels with graded core under various boundary conditions

2012 ◽  
Vol 116 (1186) ◽  
pp. 1289-1314 ◽  
Author(s):  
M. Kashtalyan ◽  
B. Woodward
Keyword(s):  
Finite Element ◽  
Boundary Conditions ◽  
Sandwich Panels ◽  
Stress Concentrations ◽  
Displacement Fields ◽  
Various Boundary Conditions ◽  
The Core ◽  
The Face ◽  
3D Elasticity ◽  
3D Finite Element Method

Abstract Sandwich panels are widely used in the aerospace industry instead of solid plates due to their high flexural stiffness-to-weight and flexural strength-to-weight ratios. However due to the mismatch of properties between the face sheets and the core, stress concentrations can occur at the face sheet/core interfaces, often leading to delamination. One possible solution to this problem is the introduction of a graded core — a core in which the properties vary gradually from the face sheets to the core centre, eliminating any abrupt changes in properties. In this paper a 3D finite element method, fully validated through comparison with results from the literature and a 3D elasticity solution, is applied to modelling of sandwich panels with graded core. The approach makes use of graded elements to study the effect of varying the boundary conditions on the elastic deformation of the panel subject to uniformly distributed loading. Comparative analysis of stress and displacement fields in sandwich panels with homogeneous and graded cores is carried out under various combinations of simply supported, clamped and free edges.

A New 3D Finite Element for Sandwich Beams With a Viscoelastic Core

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Kamel Amichi ◽  
Noureddine Atalla
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Boundary Conditions ◽  
Numerical Results ◽  
Sandwich Beams ◽  
3D Finite Element ◽  
Various Boundary Conditions ◽  
The Core ◽  
Viscoelastic Core ◽  
Displacement Approach

A sandwich finite element for laminated steels is presented. It is based on a discrete displacement approach and allows for both symmetrical and unsymmetrical configurations. The three-layer sandwich model is built assuming a Timoshenko hypothesis for the viscoelastic core and Euler–Bernoulli hypotheses for the elastic faces, but the latter is modified to account for the rotational influence of the transversal shearing in the core. The validity and accuracy of the presented element are assessed through comparisons with numerical results of sandwich beams and sandwich rings with a variety of geometrical and mechanical properties and various boundary conditions. The present results are also compared with analytical, finite element, and experimental solutions for various boundary conditions.

Finite element method and analytical analysis of static and dynamic pull-in instability of a functionally graded microplate

2020 ◽  
pp. 107754632098020
Author(s):  
Arang Pazhouheshgar ◽  
Yashar Haghighatfar ◽  
Amirhossein Moghanian
Keyword(s):  
Finite Element ◽  
Boundary Conditions ◽  
Power Laws ◽  
Functionally Graded ◽  
Numerical Results ◽  
Damping Coefficient ◽  
Various Boundary Conditions ◽  
Crucial Effect ◽  
Fringing Field ◽  
Material Power

The static and dynamic pull-in phenomenon of a functionally graded Al/Al2O3 microplate, considering the damping coefficient and fringing field effects, has been analyzed because of its crucial effect in micro-electromechanical systems application, especially in microswitches. The nonlinear equation of motion of functionally graded microplate has been derived using Hamilton’s principle, and solved analytically. Furthermore, a finite element code has been developed to solve the problem. Comparing the theoretical and numerical results for specific boundary conditions demonstrates that the numerical solution predicts the pull-in phenomenon with the least errors; and it can be used for various material power laws, damping coefficients, and initial gaps between the microplate and the substrate. The numerical results for various boundary conditions demonstrate that by increasing the damping coefficient, the dynamic pull-in voltage is also increased, and pull-in time will slow down. Moreover, the effect of power law and applied voltage on the pull-in instability is investigated.

The Use of Advanced Transient Structural Codes to Study Interior Gun Dynamics

1991 ◽  
Author(s):  
Stephen Wilkerson
Keyword(s):  
Kinetic Energy ◽  
Boundary Conditions ◽  
Numerical Models ◽  
Three Dimensional ◽  
Numerical Results ◽  
Numerical Techniques ◽  
Modeling Process ◽  
Numerical Studies ◽  
Areas Of Concern

Abstract Three-dimensional numerical models used to analyze the in-bore dynamics of kinetic energy projectiles are presented. The intricate modeling process, boundary conditions, and assumptions used in the analysis are given. Numerical results are analyzed and presented to show the importance of three-dimensional numerical studies. Finally possible areas of concern and future improvements in the numerical techniques used are reviewed.

Experimental and Numerical Study of the Vibration of Stationary and Rotating Annular Disks

2016 ◽  
Vol 138 (5) ◽  
Author(s):  
Salem Bashmal ◽  
Rama Bhat ◽  
Subhash Rakheja
Keyword(s):  
Boundary Conditions ◽  
Numerical Study ◽  
Numerical Results ◽  
Experimental Investigations ◽  
Modal Characteristics ◽  
Out Of Plane ◽  
Modes Of Vibration ◽  
Vibration Responses ◽  
Support Conditions ◽  
Annular Disks

Numerical and experimental investigations are carried out to study the combined effect of rotation and support nonuniformity on the modal characteristics of circular thick disks. The laboratory experiments on stationary and rotating circular disks are conducted to investigate the effects of partial support conditions on the in-plane and out-of-plane vibration responses of annular disks with different radius ratios. Numerical results suggested that the nonuniformity of the support along the circumferential directions of the boundaries affects the modal characteristics of the disk along the in-plane and out-of-plane directions, while introducing additional coupling between the modes. Specifically, some of the frequency peaks in the frequency spectrum obtained under uniform boundary conditions split into two distinct peaks in the presence of a point support. The results show that the in-plane modes of vibration are comparable with those associated with out-of-plane modes and are contributing to the total noise radiation. The coupling between in-plane and out-of-plane modes is found to be quite significant due to the nonuniformity of the boundary conditions. The experimental study confirms the split in natural frequencies of the disk that is observed in the numerical results due to both rotation and support nonuniformity. The applicability and accuracy of the formulations is further examined through analysis of modal characteristics of a railway wheel in contact with the rail.

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