Simulation of Thin-Walled Members with Arbitrary-Shaped Cross-Sections for Static and Dynamic Analyses

2020 ◽  
Vol 20 (12) ◽  
pp. 2050128
Author(s):  
A. H. A. Abdelrahman ◽  
Siwei Liu ◽  
Yao-Peng Liu ◽  
Siu-Lai Chan
Keyword(s):  
Finite Element ◽  
Cross Sections ◽  
Time History ◽  
Finite Element Models ◽  
Closed Form Solutions ◽  
Dynamic Analyses ◽  
Python Scripting ◽  
Thin Walled ◽  
Shell Finite Element ◽  
Dynamic Time

The main objective of this paper is to validate a finite-element (FE) modeling protocol to simulate thin-walled members for static and dynamic analyses. Arbitrary-shaped cross-sections, including open, closed, and multicellular sections can be efficiently modeled for further advanced study. The framework is thoroughly validated and verified using the existing analytical and closed-form solutions, as well as experimental results available in literature. This work is motivated by the higher accuracy of the shell FE-based modeling to capture the local and global complex behaviors of thin-walled members with asymmetric sections. Higher computational expenses, however, are required for such sophisticated shell finite element models (SFEM). Accordingly, a framework hosted in MATLAB and implementing the python scripting technique in ABAQUS, is developed, which includes eigen buckling, static nonlinear, modal frequency and dynamic time-history analyses. For a more modeling convenience, various parameters are incorporated such as imperfections, residual stresses, material definitions, element choice, meshing control, and boundary conditions. Several examples are provided to illustrate the application of the proposed framework, and to prove the robustness and accuracy of the generated FE models. This paper concludes with the efficiency of implementing SFEMs for simulating thin-walled members; thereby, establishing a more accurate and advanced structural analysis.

INFLUENCE OF INCLINED STIFFENERS IN I-BEAM CONNECTIONS ON BIMOMENT TRANSFERRING

2021 ◽  
Vol 95 (3) ◽  
pp. 47-58
Author(s):  
I.N. SERPIK ◽  
◽  
R.O. SHKOLYARENKO ◽  
Keyword(s):  
Finite Element ◽  
Point Of View ◽  
Frame Structures ◽  
Engineering Practice ◽  
Finite Element Models ◽  
Free Theory ◽  
Scientific Papers ◽  
Thin Walled ◽  
Shell Finite Element ◽  
Finite Element Schemes

Shear-free theory of V.Z. Vlasov remains one of the most reasonable approaches to calculating thin-walled bars taking into account constrained torsion. At the same time, the use of this theory for the analysis of deformations of frame structures still requires research in terms of the conditions for transferring forces in bar connections. As noted in some scientific papers, the balance of bimoments can be significantly broken at the joints of thin-walled bars of an open profile in some designs. This paper deals with this phenomenon for steel I-beam profiles, associated with the presence of inclined stiffeners in joint units. Using shell finite element models, the influence of inclined stiffeners on the appearance of bimoment jumps at the pairwise connection of bars is shown. A dependence is derived that makes it possible to take into account the stiffness of the inclined edge in the bar models from the point of view of the restraint of cross-section warping. On the basis of numerical experiments, it was determined that the introduction of such stiffness into the bar finite element schemes of frame structures allows to reflect the condition of bars interaction in the transferring of bimoments with a sufficiently high accuracy for engineering practice.

Elastoplastic analysis of thin-walled bars in the context of Generalised Beam Theory

2019 ◽  
Author(s):  
Miguel Abambres ◽  
Dinar Camotim ◽  
Nuno Silvestre
Keyword(s):  
Finite Element ◽  
Beam Theory ◽  
Finite Element Models ◽  
Inelastic Analysis ◽  
Arbitrary Loading ◽  
Steel Bars ◽  
Thin Walled ◽  
Shell Finite Element ◽  
Global Deformation ◽  
Generalised Beam Theory

A formulation of the Generalised Beam Theory (GBT) is presented for the 1st order inelastic analysis of thin-walled steel bars subjected to arbitrary loading and boundary conditions. Five illustrative examples are shown to validate the theory for cases involving global deformation only, namely uniform bending, non-uniform bending, combined bending and axial compression, and non-uniform torsion. Lastly, the results are validated against ABAQUS using beam and shell finite element models. The correlation is typically great concerning equilibrium paths, deformed configurations, and stress diagrams. In those cases where results do not compare so well, possible causes are pointed out.

Nonorthogonal solution for thin-walled members – applications and modelling considerations

2006 ◽  
Vol 33 (4) ◽  
pp. 440-450 ◽  
Author(s):  
R Emre Erkmen ◽  
Magdi Mohareb
Keyword(s):  
Finite Element ◽  
Beam Theory ◽  
Companion Paper ◽  
Finite Element Models ◽  
Element Analysis ◽  
Steel Members ◽  
Longitudinal Stiffeners ◽  
Thin Walled ◽  
Shell Finite Element ◽  
Orthogonal Coordinates

In a companion paper (R.E. Erkmen and M. Mohareb. 2006. Canadian Journal of Civil Engineering, 33: 421–439.), three finite elements based on the Vlasov thin-walled beam theory were formulated using a nonorthogonal coordinate system. Although the associated derivations are more elaborate than in more conventional solutions based on orthogonal coordinates, the new elements offer more modelling capabilities and flexibility in modelling structural steel members, a feature that is illustrated in this paper. In this context, the current paper presents four details in steel construction that were conveniently modelled within the new solution scheme. The applications involve thin-walled members with coped flanges, rectangular holes reinforced with longitudinal stiffeners, and eccentric supports. Comparisons with established shell finite element models using ABAQUS suggest the validity of the new solution. Key words: open sections, finite element analysis, thin-walled members, coped flanges, rectangular holes, eccentric supports.

Post-buckling inelastic analysis of thin-walled metal members using the Generalised Beam Theory

2019 ◽  
Author(s):  
Miguel Abambres ◽  
Dinar Camotim ◽  
Miguel Abambres
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Beam Theory ◽  
Flow Theory ◽  
Promising Alternative ◽  
Inelastic Analysis ◽  
Post Buckling ◽  
Thin Walled ◽  
Shell Finite Element ◽  
Generalised Beam Theory

A 2nd order inelastic Generalised Beam Theory (GBT) formulation based on the J2 flow theory is proposed, being a promising alternative to the shell finite element method. Its application is illustrated for an I-section beam and a lipped-C column. GBT results were validated against ABAQUS, namely concerning equilibrium paths, deformed configurations, and displacement profiles. It was concluded that the GBT modal nature allows (i) precise results with only 22% of the number of dof required in ABAQUS, as well as (ii) the understanding (by means of modal participation diagrams) of the behavioral mechanics in any elastoplastic stage of member deformation .

First and Second Order Elastoplastic Analyses of Thin-Walled Metal Members using Generalized Beam Theory

2018 ◽  
Author(s):  
Miguel Abambres
Keyword(s):  
Finite Element ◽  
Stainless Steel ◽  
Cross Section ◽  
Beam Theory ◽  
Second Order ◽  
Flow Rule ◽  
Non Linear ◽  
Thin Walled ◽  
Shell Finite Element ◽  
Generalized Beam Theory

Original Generalized Beam Theory (GBT) formulations for elastoplastic first and second order (postbuckling) analyses of thin-walled members are proposed, based on the J2 theory with associated flow rule, and valid for (i) arbitrary residual stress and geometric imperfection distributions, (ii) non-linear isotropic materials (e.g., carbon/stainless steel), and (iii) arbitrary deformation patterns (e.g., global, local, distortional, shear). The cross-section analysis is based on the formulation by Silva (2013), but adopts five types of nodal degrees of freedom (d.o.f.) – one of them (warping rotation) is an innovation of present work and allows the use of cubic polynomials (instead of linear functions) to approximate the warping profiles in each sub-plate. The formulations are validated by presenting various illustrative examples involving beams and columns characterized by several cross-section types (open, closed, (un) branched), materials (bi-linear or non-linear – e.g., stainless steel) and boundary conditions. The GBT results (equilibrium paths, stress/displacement distributions and collapse mechanisms) are validated by comparison with those obtained from shell finite element analyses. It is observed that the results are globally very similar with only 9% and 21% (1st and 2nd order) of the d.o.f. numbers required by the shell finite element models. Moreover, the GBT unique modal nature is highlighted by means of modal participation diagrams and amplitude functions, as well as analyses based on different deformation mode sets, providing an in-depth insight on the member behavioural mechanics in both elastic and inelastic regimes.

Experimental and numerical studies on failure and energy absorption of composite thin-walled square tubes under quasi-static compression loading

2020 ◽  
Vol 21 (6) ◽  
pp. 623-634
Author(s):  
Haolei Mou ◽  
Zhenyu Feng ◽  
Jiang Xie ◽  
Jun Zou ◽  
Kun Zhou
Keyword(s):  
Finite Element ◽  
Shell Model ◽  
Energy Absorption ◽  
Failure Mode ◽  
Failure Criterion ◽  
Finite Element Models ◽  
Static Compression ◽  
Compression Loading ◽  
Thin Walled ◽  
Simulation Results

AbstractTo analysis the failure and energy absorption of carbon fiber reinforced polymer (CFRP) thin-walled square tube, the quasi-static axial compression loading tests are conducted for [±45]3s square tube, and the square tube after test is scanned to further investigate the failure mechanism. Three different finite element models, i.e. single-layer shell model, multi-layer shell model and stacked shell mode, are developed by using the Puck 2000 matrix failure criterion and Yamada Sun fiber failure criterion, and three models are verified and compared according to the experimental energy absorption metrics. The experimental and simulation results show that the failure mode of [±45]3s square tube is the local buckling failure mode, and the energy are absorbed mainly by intralaminar and interlaminar delamination, fiber elastic deformation, fiber debonding and fracture, matrix deformation cracking and longitudinal crack propagation. Three different finite element models can reproduce the collapse behaviours of [±45]3s square tube to some extent, but the stacked shell model can better reproduce the failure mode, and the difference of specific energy absorption (SEA) is minimum, which shows the numerical simulation results are in better agreement with the test results.

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