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Articles de revues sur le sujet "3D beam element"
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Dvořáková, Edita, et Bořek Patzák. « ON COMPARISON OF 3D ISOGEOMETRIC TIMOSHENKO AND BERNOULLI BEAM FORMULATIONS ». Acta Polytechnica CTU Proceedings 30 (22 avril 2021) : 12–17. http://dx.doi.org/10.14311/app.2021.30.0012.
Texte intégralRésumé :
Application of isogeometric analysis (IGA) for curved beams is very convenient for its ability of exact representation of curved geometries. Several beam formulation has been presented since the introduction of IGA. In this paper, two different beam formulations are presented: Bernoulli beam formulation of A. M. Bauer et al. [1], and Timoshenko beam element introduced by G. Zhang et al. [2]. Both beam elements are implemented and their performance is documented on the fully threedimensionalexample of helicoidal spring.
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Eskandari, Amir H., Mostafa Baghani et Saeed Sohrabpour. « A Time-Dependent Finite Element Formulation for Thick Shape Memory Polymer Beams Considering Shear Effects ». International Journal of Applied Mechanics 10, no 04 (mai 2018) : 1850043. http://dx.doi.org/10.1142/s1758825118500436.
Texte intégralRésumé :
In this paper, employing a thermomechanical small strain constitutive model for shape memory polymers (SMP), a beam element made of SMPs is presented based on the kinematic assumptions of Timoshenko beam theory. Considering the low stiffness of SMPs, the necessity for developing a Timoshenko beam element becomes more prominent. This is due to the fact that relatively thicker beams are required in the design procedure of smart structures. Furthermore, in the design and optimization process of these structures which involves a large number of simulations, we cannot rely only on the time consuming 3D finite element analyses. In order to properly validate the developed formulations, the numeric results of the present work are compared with those of 3D finite element results of the authors, previously available in the literature. The parametric study on the material parameters, e.g., hard segment volume fracture, viscosity coefficient of different phases, and the external force applied on the structure (during the recovery stage) are conducted on the thermomechanical response of a short I-shape SMP beam. For instance, the maximum beam deflection error in one of the studied examples for the Euler–Bernoulli beam theory is 7.3%, while for the Timoshenko beam theory, is 1.5% with respect to the 3D FE solution. It is noted that for thicker or shorter beams, the error of the Euler–Bernoulli beam theory even more increases. The proposed beam element in this work could be a fast and reliable alternative tool for modeling 3D computationally expensive simulations.
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Nguyen, Hoang Nam, Tran Thi Hong, Pham Van Vinh et Do Van Thom. « An Efficient Beam Element Based on Quasi-3D Theory for Static Bending Analysis of Functionally Graded Beams ». Materials 12, no 13 (8 juillet 2019) : 2198. http://dx.doi.org/10.3390/ma12132198.
Texte intégralRésumé :
In this paper, a 2-node beam element is developed based on Quasi-3D beam theory and mixed formulation for static bending of functionally graded (FG) beams. The transverse shear strains and stresses of the proposed beam element are parabolic distributions through the thickness of the beam and the transverse shear stresses on the top and bottom surfaces of the beam vanish. The proposed beam element is free of shear-looking without selective or reduced integration. The material properties of the functionally graded beam are assumed to vary according to the power-law index of the volume fraction of the constituents through the thickness of the beam. The numerical results of this study are compared with published results to illustrate the accuracy and convenience rate of the new beam element. The influence of some parametrics on the bending behavior of FGM beams is investigated.
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Chevalier, Luc, Heba Makhlouf, Benoît Jacquet-Faucillon et Eric Launay. « Modeling the influence of connecting elements in wood products behavior : a numerical multi-scale approach ». Mechanics & ; Industry 19, no 3 (2018) : 301. http://dx.doi.org/10.1051/meca/2018004.
Texte intégralRésumé :
Wood furniture is often composed of simple parts that may be modeled as beams or plates. These particularities allow using simplified approaches that reduces the number of degrees of freedom (dof for short) in a finite element simulation of the furniture's behavior. Generally, connections are not taken into account in such simulations but these connections are critical in the failure process of the furniture and it worth studying it precisely. Using a multi-scale approach, this paper introduces a numerical procedure to identify the connection contribution in the furniture's stiffness. Comparing 3D finite element calculations with a Timoshenko's beam calculation on a corner of two wooden parts, we identify the specific behavior of the connection elements (pins, nut, screw… and local 3D effects) to introduce it as a punctual 0D element in the beam code. Two validations of the approach are presented here: (i) a numerical validation by comparing the result of the beam code with a complete 3D finite element simulation on a representative plane structure of wooden furniture; (ii) an experimental validation by managing a global bending test and measuring the displacement field using digital image correlation (DIC for short).
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Poorasadion, Saeid, Jamal Arghavani, Reza Naghdabadi et Saeed Sohrabpour. « Implementation of Microplane Model Into Three-Dimensional Beam Element for Shape Memory Alloys ». International Journal of Applied Mechanics 07, no 06 (décembre 2015) : 1550091. http://dx.doi.org/10.1142/s175882511550091x.
Texte intégralRésumé :
In this study, a three-dimensional (3D) beam element based on Timoshenko beam theory is introduced for shape memory alloys (SMAs). Employing the microplane approach, we use a 3D SMA constitutive model extended from a 1D model proposed by Brinson. The SMA model is implemented into a user-defined subroutine (UMAT) in the nonlinear finite element software ABAQUS/Standard. Results of numerical examples show reasonable agreement with experimental data in proportional and non-proportional loadings. Furthermore, several applications (staple, spring, structure) are simulated and the results are compared with those of continuum elements. According to the results, the 3D SMA beam element can be used in the design and analysis of various SMA applications.
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Yob, Mohd Shukri, Shuhaimi Mansor et Razali Sulaiman. « Finite Element Modelling to Predict Equivalent Stiffness of 3D Space Frame Structural Joint Using Circular Beam Element ». Applied Mechanics and Materials 431 (octobre 2013) : 104–9. http://dx.doi.org/10.4028/www.scientific.net/amm.431.104.
Texte intégralRésumé :
In automotive industry, thin walled beam is widely used to build vehicles structure. Vehicle structure is built by joining thin walled beams using various welding techniques. The usage of thin walled structure in automotive is important to improve vehicle performance by offering better strength-to-weight ratio. However the application of thin walled structure will cause few drawbacks to vehicle structure. When thin walled beam or structure is loaded with compression load, at certain limit it will undergo local or global buckling. Another problem is when thin walled beam is joined to other thin walled beams, it will show unexpected deformation which called joint flexibility. Both phenomena will cause numerical and analytical model to predict stiffness of structure tend to deviate from experimental result. In vehicle structure fabrication 3D space frame is used a lot. As a case study for this application, area around car bulkhead where cross member, side sill and A pillar are connected to each other at right angle is studied. The intention of this research work is to produce validated finite element model to predict equivalent stiffness of 3D space frame structural joint. Finite element, shell element is most common technique used to model the joined structure. However it is known that shell model cannot produce good result. In this result work, modelling of equivalent stiffness for 3D space frame structural joint is presented. The result shows, using this model the accuracy is about 65%. New modelling technique is proposed to increase the accuracy based on solid model. By introducing circular beam elements at welding area, it is found that accuracy improves up to 90%.
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Murín, Justín, Vladimír Kutiš, Viktor Královič et Tibor Sedlár. « 3D Beam Finite Element Including Nonuniform Torsion ». Procedia Engineering 48 (2012) : 436–44. http://dx.doi.org/10.1016/j.proeng.2012.09.537.
Texte intégral
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Viet, N. V., W. Zaki et Quan Wang. « Free vibration characteristics of sectioned unidirectional/bidirectional functionally graded material cantilever beams based on finite element analysis ». Applied Mathematics and Mechanics 41, no 12 (18 novembre 2020) : 1787–804. http://dx.doi.org/10.1007/s10483-020-2664-8.
Texte intégralRésumé :
AbstractAdvancements in manufacturing technology, including the rapid development of additive manufacturing (AM), allow the fabrication of complex functionally graded material (FGM) sectioned beams. Portions of these beams may be made from different materials with possibly different gradients of material properties. The present work proposes models to investigate the free vibration of FGM sectioned beams based on one-dimensional (1D) finite element analysis. For this purpose, a sample beam is divided into discrete elements, and the total energy stored in each element during vibration is computed by considering either Timoshenko or Euler-Bernoulli beam theories. Then, Hamilton’s principle is used to derive the equations of motion for the beam. The effects of material properties and dimensions of FGM sections on the beam’s natural frequencies and their corresponding mode shapes are then investigated based on a dynamic Timoshenko model (TM). The presented model is validated by comparison with three-dimensional (3D) finite element simulations of the first three mode shapes of the beam.
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Murín, Justín, Juraj Hrabovský et Vladimír Kutiš. « Calculation of stress in FGM beams ». MATEC Web of Conferences 157 (2018) : 06006. http://dx.doi.org/10.1051/matecconf/201815706006.
Texte intégralRésumé :
Content of the paper is oriented to calculation of elastic normal stress in the Functionally Graded Beams (FGM). Spatial variation of material properties is considered in the lateral, transversal and longitudinal direction of the straight beam. The displacements and internal forces are calculated using our new FGM finite beam element. Heterogeneous material properties are homogenized by extended mixture rules, laminate theory and reference volume element (RVE). Obtained results by our approach are evaluated and compared with the ones obtained by the 3D solid finite elements.
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Wang, Yuquan. « Improved Strategy of Two-Node Curved Beam Element Based on the Same Beam’s Nodes Information ». Advances in Materials Science and Engineering 2021 (2 septembre 2021) : 1–9. http://dx.doi.org/10.1155/2021/2093096.
Texte intégralRésumé :
The curved beam with a great initial curvature is the typical structure and applied widely in real engineering structures. The common practice in the current literature employs two-node straight beam elements as the elementary members for stress and displacement analysis, which needs a large number of divisions to fit the curved beam shape well and increases computational time greatly. In this paper, we develop an improved accurate two-node curved beam element (IC2) in 3D problems, combining the curved Timoshenko beam theory and the curvature information calculated from the same beam curve. The strategy of calculating the curvature information from the same bean curve in the IC2 beam element and then transferring the curvature information to the two-node straight beam element can greatly enhance the accuracy of the mechanical analysis with no extra calculation burden. We then introduce the finite element implementation of the IC2 beam element and verify by the complex curved beam analysis. By comparison with simulation results from the straight two-node beam element in the MIDAS (S2-MIDAS) and the three-node curved beam element adopted in the ANSYS (C3-ANSYS), the simulation results of the typical quarter arc examples under constant or variable curvature show that the IC2 beam element based on curved beam theory is a combination of efficiency and accuracy. And, it is a good choice for analysis of complex engineering rod structure with large initial curvature.
Thèses sur le sujet "3D beam element"
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Gao, Sasa. « Development of a new 3D beam finite element with deformable section ». Thesis, Lyon, 2017. http://www.theses.fr/2017LYSEI026/document.
Texte intégralRésumé :
Le nouvel élément de poutre est une évolution d'un élément de Timoshenko poutre avec un nœud supplémentaire situé à mi-longueur. Ce nœud supplémentaire permet l'introduction de trois composantes supplémentaires de contrainte afin que la loi constitutionnelle 3D complète puisse être utilisée directement. L'élément proposé a été introduit dans un code d'éléments finis dans Matlab et une série d'exemples de linéaires/petites contraintes ont été réalisées et les résultats sont systématiquement comparés avec les valeurs correspondantes des simulations ABAQUS/Standard 3D. Ensuite, la deuxième étape consiste à introduire le comportement orthotrope et à effectuer la validation de déplacements larges / petites contraintes basés sur la formulation Lagrangienne mise à jour. Une série d'analyses numériques est réalisée qui montre que l'élément 3D amélioré fournit une excellente performance numérique. En effet, l'objectif final est d'utiliser les nouveaux éléments de poutre 3D pour modéliser des fils dans une préforme composite textile. A cet effet, la troisième étape consiste à introduire un comportement de contact et à effectuer la validation pour un nouveau contact entre 3D poutres à section rectangulaire. La formulation de contact est dérivée sur la base de formulation de pénalité et de formulation Lagrangian mise à jour utilisant des fonctions de forme physique avec l'effet de cisaillement inclus. Un algorithme de recherche de contact efficace, qui est nécessaire pour déterminer un ensemble actif pour le traitement de contribution de contact, est élaboré. Et une linéarisation constante de la contribution de contact est dérivée et exprimée sous forme de matrice appropriée, qui est facile à utiliser dans l'approximation FEM. Enfin, on présente quelques exemples numériques qui ne sont que des analyses qualitatives du contact et de la vérification de l'exactitude et de l'efficacité de l'élément de 3D poutre proposéThe new beam element is an evolution of a two nodes Timoshenko beam element with an extra node located at mid-length. That extra node allows the introduction of three extra strain components so that full 3D stress/strain constitutive relations can be used directly. The second step is to introduce the orthotropic behavior and carry out validation for large displacements/small strains based on Updated Lagrangian Formulation. A series of numerical analyses are carried out which shows that the enhanced 3D element provides an excellent numerical performance. Indeed, the final goal is to use the new 3D beam elements to model yarns in a textile composite preform. For this purpose, the third step is introducing contact behavior and carrying out validation for new 3D beam to beam contact with rectangular cross section. The contact formulation is derived on the basis of Penalty Formulation and Updated Lagrangian formulation using physical shape functions with shear effect included. An effective contact search algorithm is elaborated. And a consistent linearization of contact contribution is derived and expressed in suitable matrix form, which is easy to use in FEM approximation. Finally, some numerical examples are presented which are only qualitative analysis of contact and checking the correctness and the effectiveness of the proposed 3D beam element
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Song, Huimin. « Rigorous joining of advanced reduced-dimensional beam models to 3D finite element models ». Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/33901.
Texte intégralRésumé :
This dissertation developed a method that can accurately and efficiently capture the response of a structure by rigorous combination of a reduced-dimensional beam finite element model with a model based on full two-dimensional (2D) or three-dimensional (3D) finite elements.
As a proof of concept, a joint 2D-beam approach is studied for planar-inplane deformation of strip-beams. This approach is developed for obtaining understanding needed to do the joint 3D-beam model. A Matlab code is developed to solve achieve this 2D-beam approach. For joint 2D-beam approach, the static response of a basic 2D-beam model is studied. The whole beam structure is divided into two parts. The root part where the boundary condition is applied is constructed as a 2D model. The free end part is constructed as a beam model. To assemble the two different dimensional model, a transformation matrix is used to achieve deflection continuity or load continuity at the interface. After the transformation matrix from deflection continuity or from load continuity is obtained, the 2D part and the beam part can be assembled together and solved as one linear system.
For a joint 3D-beam approach, the static and dynamic response of a basic 3D-beam model is studied. A Fortran program is developed to achieve this 3D-beam approach. For the uniform beam constrained at the root end, similar to the joint 2D-beam analysis, the whole beam structure is divided into two parts. The root part where the boundary condition is applied is constructed as a 3D model. The free end part is constructed as a beam model. To assemble the two different dimensional models, the approach of load continuity at the interface is used to combine the 3D model with beam model. The load continuity at the interface is achieved by stress recovery using the variational-asymptotic method. The beam properties and warping functions required for stress recovery are obtained from VABS constitutive analysis. After the transformation matrix from load continuity is obtained, the 3D part and the beam part can be assembled together and solved as one linear system. For a non-uniform beam example, the whole structure is divided into several parts, where the root end and the non-uniform parts are constructed as 3D models and the uniform parts are constructed as beams. At all the interfaces, the load continuity is used to connect 3D model with beam model. Stress recovery using the variational-asymptotic method is used to achieve the load continuity at all interfaces. For each interface, there is a transformation matrix from load continuity. After we have all the transformation matrices, the 3D parts and the beam parts are assembled together and solved as one linear system.
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De, Frias Lopez Ricardo. « A 3D finite beam element for the modelling of composite wind turbine wings ». Thesis, KTH, Bro- och stålbyggnad, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-119079.
Texte intégralRésumé :
The main purpose of this thesis is to develop a 3D beam element in order to model wind turbine wings made of composite materials. The proposed element is partly based on the formulation of the classical beam element of constant cross-section without shear deformation (Euler-Bernoulli) and including Saint-Venant torsional effects for isotropic materials, similarly to the one presented in Batoz & Dhatt (1990, pp.147-190). The main novelty consists in the addition of the coupling between axial and bending with torsional effects that may arise when using composite materials. PreComp, a free access code developed by the National Renewable Energy Laboratory (NREL) to provide structural properties for composite blades, is used to obtain the section properties for the beam element. Its performance is assessed, showing its inaccuracy especially when calculating torsional related constants when webs are present in the cross-section. Shell models of constant cross-section cantilever blades are developed to assess the performance of the beam elements, including or not coupling terms. Natural frequencies and displacements under static loads are compared for different study cases of increasing complexity. For fiber-reinforced materials, elements with coupling terms show good agreement with the shell model, especially for the dynamic problem. Elements without coupling terms are unable to capture the dynamic behavior, as these terms seem to have a higher effect on the results when compared to the static case (especially the FT term).
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Lyu, Chunhao. « Progressive Collapse Resistance of Post-and-Beam Mass Timber Buildings : Experimental and Numerical Investigations on 2D and 3D Substructures ». Thesis, Griffith University, 2021. http://hdl.handle.net/10072/406078.
Texte intégralRésumé :
Mid-rise to tall timber buildings are internationally gaining popularity. Reaching heights greater than 5 to 6 storeys has been made possible by the availability of engineered wood products, such as Laminated Veneer Lumber (LVL), Glued laminated timber (Glulam) and Cross Laminated Timber (CLT). These buildings are referred to as “mass timber buildings”. As the height of timber buildings increases, so do their potential risks of progressive collapse. Progressive collapse is characterised by a local failure of a load-bearing structural element which may propagate through the whole building, and ultimately causes its partial or entire collapse. While progressive collapse mechanisms of reinforced concrete and steel buildings have been widely researched, limited studies have been carried out on mass timber buildings. Their ability to resist progressive collapse and their load transfer mechanisms after the loss of a load-bearing element are currently unclear.
First, to gain an initial understanding of the progressive collapse behaviour of post-and-beam mass timber buildings, a series of scaled-down 1×2-bay (2D) timber frame substructures were tested under a middle column removal scenario. The behaviour of the frames and the ability of three types of commercially used beam-to-column connections and a proposed novel connection, to develop catenary action under large deformations was measured. The system capacity in terms of the Uniformly Distributed Pressure (UDP) was also quantified. The test results showed that only the proposed novel connector was able to sustain the design pressure in international design specifications if no dynamic increase factor was considered, and therefore presented a potential solution to improve the robustness of post-and-beam mass timber buildings. Furthermore, progressive collapse of post-and-beam mass timber buildings cannot be resisted by the frame alone using the investigated currently used connections and alternative load paths must be found.
Second to further explore the mechanisms of post-and-beam mass timber buildings against progressive collapse, four scaled-down 2×2-bay (3D) substructures, with CLT panels, were constructed and tested in the laboratory. Three substructures were tested under an edge column removal scenario, with substructures manufactured from two different types of beam-to-column connections. Namely, two tests were performed with a connection type commonly used in Australia, and one test with the proposed novel connection investigated earlier. The last substructure was subjected to two different corner column removal scenarios, with the substructure tested twice under different CLT panels configurations. The substructure was assembled from the commonly used in Australia beam-to-column connection. In all tests, two Uniformly Distributed Pressures (UDP) were applied to the floors in two stages: (i) a constant UDP of 4.8 kPa was first applied to the bays not adjacent to the removed column and (ii) an idealised UDP was then increasingly applied to the remaining bay(s) through a hydraulic jack connected to a six-point loading tree. The load redistribution mechanisms (alternative load paths), the structural response and failure modes were recorded. In general, experimental test results showed that the applied load was principally transferred to the three columns the closest to the removed column and that the CLT panels spanning over two bays were efficient in resisting the load. The layout of the CLT panels plays a critical role in resisting progressive collapse. A simplified analytical model, consistent with the current industry design practice and pre-defined alternative load paths, was used to predict the ultimate resistance capacity of the tested specimens and compared to the experimental capacities. Overall, the simplified methodology was found to be conservative.
Third, finite element (FE) models were developed using the component model and validated against the 2D and 3D experimental results. The properties of the springs to be used in the component model were obtained from additional experimental component tests. CLT panels were simulated using layered shell elements while beam elements were used for the beams and columns. In the 2D numerical model, the ultimate load was accurately predicted and the development of compressive arch and catenary actions were well reproduced. The validated 2D model was then used to build the 3D model. For all tests, the 3D numerical models accurately predicted the overall load-displacement responses, load redistribution mechanisms, failure modes and strain developments in the beams and CLT panels. The validated numerical models were used to conduct a series of parametric studies to further examine the structural responses of the post-and-beam mass timber buildings. The results indicated that the structural capacity would be reduced when only using onebay long CLT panels, compared to using either staggered or all two-bay long CLT panels. Also, beam-to-column connections of the frames connected to the removed column could locally support the CLT panels above, providing an additional alternative load path for the structure in the context of progressive collapse, which is normally neglected in industry design practice.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Eng & Built Env
Science, Environment, Engineering and Technology
Full Text
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Possidente, Luca. « Development and application of corotational finite elements for the analysis of steel structures in fire ». Doctoral thesis, Università degli studi di Trento, 2021. http://hdl.handle.net/11572/289943.
Texte intégralRésumé :
Utbredningen av en brand inuti en byggnad kan leda till global eller lokal strukturell kollaps, särskilt i stålramkonstruktioner. Faktum är att stålkonstruktioner är särskilt utsatta för termiska angrepp på grund av ett högt värde av stålkonduktivitet och tvärsnitten med små tjockleken. Som en viktig aspekt av konstruktionen bör brandsäkerhetskrav uppnås antingen enligt föreskrivande regler eller enligt antagande av prestationsbaserad brandteknik. Trots möjligheten att använda enkla metoder som involverar membersanalys kombinerat med nominella brandkurvor, är en mer exakt analys av det termomekaniska beteendet hos en stålkonstruktion ett tilltalande alternativ eftersom det kan leda till mer ekonomiska och effektiva lösningar genom att ta hänsyn till möjliga gynnsamma mekanismer.
Denna analys kräver vanligtvis utredning av delar av strukturen eller till och med av hela strukturen. För detta ändamål och för att få en djupare kunskap om strukturelementens beteende vid förhöjd temperatur bör numerisk simulering användas. I denna avhandling utvecklades och användes termomekaniska finita element som är lämpliga för analys av stålkonstruktioner utsätta för brand. Relevanta fallstudier utfördes.
Utvecklingen av både ett termomekaniskt skal- och 3D balkelement baserade på en korotationsformulering presenteras. De flesta relevanta strukturfall kan undersökas på ett adekvat sätt genom att antingen använda något av dessa element eller kombinera dem. Korotationsformuleringen är väl lämpad för analyser av strukturer där stora förskjutningar, men små töjningar förekommer, som i fallet med stålkonstruktioner i brand. Elementens huvuddrag beskrivs, liksom deras karakterisering i termomekaniskt sammanhang. I detta avseende övervägdes materialnedbrytningen på grund av temperaturökningen och den termiska expansionen av stål vid härledningen av elementen. Dessutom presenteras en grenväxlingsprocedur för att utföra preliminära instabilitetsanalyser och få viktig
inblick i efterknäckningsbeteendet hos stålkonstruktioner som utsätts för brand.
Tillämpningen av de utvecklade numeriska verktygen ges i den del av avhandlingen som ägnas åt det publicerade forskningsarbetet. Flera aspekter av knäckningen av stålkonstruktionselement vid förhöjd temperatur diskuteras. I Artikel I tillhandahålls överväganden om påverkan av geometriska imperfektioner på beteendet hos komprimerade stålplattor och kolonner vid förhöjda temperaturer, liksom implikationer och resultat av användningen av grenväxlingsprocedur. I Artikel II valideras det föreslagna 3D-balkelementet genom meningsfulla fallstudier där torsionsdeformationer är signifikanta. De utvecklade balk- och skalelementen används i en undersökning av knäckningsmotstånd hos komprimerade vinkel-, Tee- och korsformade stålprofiler vid förhöjd temperatur som presenteras i Artikel III. En förbättrad knäckningskurva för design presenteras i detta arbete. Som ett exempel på tillämpningen av principerna för brandsäkerhetsteknik presenteras en omfattande analys i Artikel IV. Två relevanta brandscenarier identifieras för den undersökta byggnaden, som modelleras och
analyseras i programmet SAFIR.The ignition and the propagation of a fire inside a building may lead to global or local structural collapse, especially in steel framed structures. Indeed, steel structures are particularly vulnerable to thermal attack because of a high value of steel conductivity and of the small thickness that characterise the cross-sections. As a crucial aspect of design, fire safety requirements should be achieved either following prescriptive rules or adopting performance-based fire engineering. Despite the possibility to employ simple methods that involve member analysis under nominal fire curves, a more accurate analysis of the thermomechanical behaviour of a steel structural system is an appealing alternative, as it may lead to more economical and efficient solutions by taking into account possible favourable mechanisms. This analysis typically requires the investigation of parts of the structure or even of the whole structure. For this purpose, and in order to gain a deeper knowledge about the behaviour of structural members at elevated temperature, numerical simulation should be employed. In this thesis, thermomechanical finite elements, suited for the analyses of steel structures in fire, were developed and exploited in numerical simulation of relevant case studies. The development of a shell and of a 3D beam thermomechanical finite element based on a corotational formulation is presented. Most of the relevant structural cases can be adequately investigated by either using one of these elements or combining them. The corotational formulation is well suited for the analyses of structures in which large displacements, but small strains occur, as in the case of steel structures in fire. The main features of the elements are described, as well as their characterization in the thermomechanical context. In this regard, the material degradation due to the temperature increase and the thermal expansion of steel were considered in the derivation of the elements. In addition, a branch-switching procedure to perform preliminary instability analyses and get important insight into the post-buckling behaviour of steel structures subjected to fire is presented. The application of the developed numerical tools is provided in the part of the thesis devoted to the published research work. Several aspects of the buckling of steel structural elements at elevated temperature are discussed. In paper I, considerations about the influence of geometrical imperfections on the behaviour of compressed steel plates and columns at elevated temperatures are provided, as well as implications and results of the employment of the branch-switching procedure. In Paper II, the proposed 3D beam element is validated for meaningful case studies, in which torsional deformations are significant. The developed beam and shell elements are employed in an investigation of buckling resistance of compressed angular, Tee and cruciform steel profiles at elevated temperature presented in Paper III. An improved buckling curve for design is presented in this work. Furthermore, as an example of the application of Fire Safety Engineering principles, a comprehensive analysis is proposed in Paper IV. Two relevant fire scenarios are identified for the investigated building, which is modelled and analysed in the software SAFIR.
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Gunbring, Freddie. « Prediction and Modelling of Fastener Flexibility Using FE ». Thesis, Linköping University, Department of Management and Engineering, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-11428.
Texte intégralRésumé :
This report investigates the feasibility and accuracy of determining fastener flexibility with 3D FE and representing fasteners in FE load distribution models with simple elements such as springs or beams. A detailed study of 3D models compared to experimental data is followed by a parametric study of different shell modelling techniques. These are evaluated and compared with industry semi-empirical equations.
The evaluated 3D models were found to match the experimental values with good precision. Simulations based on these types of 3D models may replace experimental tests. Two different modelling techniques were also evaluated for use in load distribution models. Both were verified to work very well with representing fastener installations in lap-joints using the ABAQUS/Standard solver. Further improvement of one of the models was made through a modification scale factor. Finally, the same modelling technique was verified using the NASTRAN solver.
To summarize, it is concluded that:
• Detailed 3D-models with material properties defined from stress-strain curves correspond well to experiments and simulations may replace actual flexibility tests.
• At mid-surface modelling of the connecting parts, beam elements with a circular cross section as a connector between shell elements is an easy and accurate modelling technique, with the only data input of bolt material and dimension.
• Using connector elements is accurate only if the connecting parts are modelled in the same plane, i.e. with no offset. Secondary bending due to offset should only be accounted for once and only once throughout the analysis, and it is already included in the flexibility input.
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Ferradi, Mohammed Khalil. « Nouveaux modèles d'éléments finis de poutres enrichies ». Thesis, Paris Est, 2015. http://www.theses.fr/2015PESC1173/document.
Texte intégralRésumé :
Les éléments de poutres classiques (Euler-Bernoulli, Timoshenko, Vlassov…), sont tous basés sur certaines hypothèses simplificatrices, qui ont pour conséquence de fixer la forme de la cinématique de l'élément. Ceci revient à réduire un modèle ayant par définition une infinité de d.d.l., à un modèle avec un nombre fini de d.d.l.. Quel que soit donc le chargement auquel sera soumise la poutre, elle se déformera toujours selon la cinématique adoptée au départ. L'objectif de cette thèse est de s'affranchir des hypothèses inhérentes aux modèles de poutres classiques, pour développer un nouveau modèle de poutre enrichie, capable de représenter d'une manière précise les déformations globales aussi bien que locales. Ce type d'élément, permettra la représentation de la flexion transversale dans une poutre, de capturer des effets locaux, produits par exemple par un câble d'ancrage ou de précontrainte sur un tablier de pont, ou encore de traiter le traînage de cisaillement sur des poutres à grandes largeurs. Après un bref rappel de quelques théories de poutres classiques, on présentera dans les deux premiers articles, une nouvelle méthode pour la détermination de modes transversaux et de gauchissements, basée sur une analyse aux valeurs propres d'un modèle mécanique de la section pour l'obtention de la base des modes transversaux, et un procédé d'équilibre itératif pour la détermination de la base des modes de gauchissements. La cinématique ainsi définie, le PTV sera utilisé pour obtenir les équations d'équilibre de la poutre, pour ensuite en déduire la matrice de raideur à partir de leur solution analytique. Dans le troisième article, une nouvelle méthode est proposée pour l'obtention d'une cinématique plus appropriée, où les bases des modes transversaux et de gauchissements sont obtenues en fonction des chargements extérieurs. Cette méthode est basée sur l'application de la méthode des développements asymptotiques à la résolution des équations fortes décrivant l'équilibre d'une poutreThe available classical beam elements (such as Euler-Bernoulli, Timoshenko, Vlassov…), are all based on some hypothesis, that have the effect of defining the kinematic of the beam. This is equivalent to reducing a model with an infinity of d.o.f., to a model with a finite d.o.f.. Thus, for arbitrary loadings, the beam will always deform according to the adopted kinematics. The objective of this thesis, is to completely overcome all the hypothesis behind the classical beam models, to develop a new higher order beam model, able to represent precisely the global and local deformations. This kind of element will also allow the derivation of the transversal bending of the beam, to capture the local effects due to anchor or prestressing cables, or to treat the shear lag phenomenon in large width spans. After a brief review of some classical beam theories, we will develop in the two first articles a new method to obtain a basis for the transverse deformation and warping modes. The method is based on an eigenvalue analysis of a mechanical model of the cross section, to obtain the transverse deformation modes basis, and an iterative equilibrium scheme, to obtain the warping modes basis. The kinematic being defined, the virtual work principle will be used to derive the equilibrium equations of the beam, then the stiffness matrix will be assembled from their analytical solution. In the third article, a new method is proposed for the derivation of a more appropriate kinematic, where the transverse deformation and warping modes are obtained in function of the external loadings. The method is based on the application of the asymptotic expansion method to the strong form of the equilibrium equations describing the beam equilibrium
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Apedo, Komla Lolonyo. « Numerical modelling of inflatable structures made of orthotropic technical textiles : application to the frames of inflatable tents ». Thesis, Lyon 1, 2010. http://www.theses.fr/2010LYO10145.
Texte intégralRésumé :
L'objectif principal visé par cette thèse est de modéliser les poutres gonflables en textiles techniques orthotropes. Les approches statiques font l'objet de ce rapport. Avant d'aborder ce problème, nous avons été amenés à identifier tous les paramètres qui ont un effet direct sur les propriétés mécaniques effectives de ces composites. Ainsi, nous avons développé un modèle micro mécanique de prédiction de ces propriétés mécaniques. Le modèle proposé est basé sur l’analyse d'un volume élémentaire représentatif (VER) prenant en compte non seulement les propriétés mécaniques et la. fraction de volume de chaque phase dans le VER mais également leur géométrie et leur architecture. Chaque fil dans le VER a été modélisé comme un matériau isotrope transverse (contenant les fibres et la résine). La méthode dite d’assemblage de cylindres a été utilisée pour l’homogénéisation au niveau des fils. Une deuxième homogénéisation est ensuite réalisée. Elle prend en compte la fraction de volume de chaque constituant (fils de chaîne, fils de trame et résine non prise en compte dans les fils). Le modèle a été validé par des résultats expérimentaux existant dans la littérature. Une élude paramétrique a été menée afin d'étudier les effets des divers paramètres géométriques et mécaniques sur ces propriétés mécaniques. Dans l'analyse structurale, un modèle poutre gonflable 3D de Timoshenko en tissu orthotrope a été proposé. Il prend en compte les non-linéarités géométriques et l'effet de la force suiveuse générée par la pression de gonflage. Les équations d'équilibre non-linéaires dérivent du principe des travaux virtuels en configuration lagrangienne totale. Dans une première approche, une linéarisation a été faite autour de la configuration de référence précontrainte pour obtenir les équations adaptées aux problèmes linéaires. A titre d'exemple, le problème de flexion plane a été abordé. Quatre cas de conditions aux limites ont été traités et les résultats obtenus améliorent les modèles existants dans le cas de tissu isotrope. Les charges de plissage ont été également proposées dans chaque cas traité. Dans une deuxième approche, les équations non-linéaires ont été discrétisées par la méthode des éléments finis. Deux types de solutions ont été alors proposées : les solutions aux problèmes éléments finis linéaires obtenues par une linéarisation des équations discrétisées autour de la configuration de référence précontrainte et les solutions aux problèmes éléments finis non-linéaires réalisées en adoptant une méthode Quasi-Newton sous sa forme incrémentale. A titre d’exemple, la flexion d’une poutre encastrée-libre a été étudiée et les résultats améliorent les modèles théoriques. Le modèle éléments finis non-linéaire a été comparé favorablement à un modèle éléments finis coque mince 3D. Une étude paramétrique a été ensuite effectuée. Elle a porté sur l'influence des propriétés mécaniques et sur de la pression de gonflage sur la réponse de la poutre. Les solutions éléments finis linéaires se sont avérées proches des résultats théoriques linéarisés d'une part et les résultats du modèle éléments finis non-linéaire se sont avérés proches des résultats du modèle linéaire dans le cas des propriétés mécaniques élevées alors que le modèle éléments finis non-linéaire est indispensable pour modéliser ces poutres lorsque les propriétés mécaniques du tissu sont faiblesThe main objective of this thesis was to model inflatable beams made frorn orthotropic woven fabric composites. The static aspects were investigated in this report. Before planning to develop these models, it was necessary to know all the parameters which have a direct effect on the effective mechanical properties these composites. Thus, a micro mechanical model was performed for predicting the effective mechanical properties. The proposed model was based on the analysis of the representative volume element (RVE). The model took into account not only the mechanical properties and volume fraction of each components in the RVE but also their geometry and architecture. Each yarn in the RVE was modelled as a transversely isotropic material (containing fibres and resin) using the concentric cylinders model (CCIVI). A second volumetric averaging which took into account the volume fraction of each constituent (warp yarn, weft yarn and resin), was performed. The model was validated favorably against experimental available data. A parametric study was conducted in order to investigate the effects of various geometrical and mechanical parameters on the elastic properties of these composites. ln the structural analysis, a 3D Timoshenko airbeam with a homogeneous orthotropic woven fabric (OWF) was addressed. The model took into account the geometrical nonlinearities and the inflation pressure follower force effect. The analytical equilibrium equations were performed using the total Lagrangian form of the virtual work principle. As these equations were nonlinear, in a first approach, a linearization was performed at the prestressed reference configuration to obtain the equations devoted to linearized problems. As example, the bending problem was investigated. Four cases of boundary conditions were treated and the deflections and rotations results improved the existing models in the case of isotropic fabric. The wrinkling load in every case was also proposed. In a second approach, the nonlinear equilibrium equations of the 3DTimoshenko airbeam were discretized by the finite element method. Two finite element solutions were then investigated : finite element solutions for linearized problems which were obtained by the means of the linearization around the prestressed reference configuration of the nonlinear equations and nonlinear finite element solutions which were performed by the use of an optimization algorithm based on the Qua.si-Newton method. As an example, the bending problem of a cantilever inflated beam under concentrated load was considered and the deflection results improve the theoretical models. As these beams are made from fabric, the beam models were validated through their comparison with a 3D thin-shell finite element model. The influence of the material effective properties and the inflation pressure on the beam response was also investigated through a parametric study. The finite element solutions for linearized problems were found to be close to the theoretical linearized results. On the other hand, the results for the nonlinear finite element model were shown to be close to the results for the linearized finite element model in the case of high mechanical properties and the non linear finite element model was used to improve the linearized model when the mechanical properties of the fabric are low
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Harbrecht, Helmut, et Reinhold Schneider. « Wavelet Galerkin Schemes for 3D-BEM ». Universitätsbibliothek Chemnitz, 2006. http://nbn-resolving.de/urn:nbn:de:swb:ch1-200600452.
Texte intégralRésumé :
This paper is intended to present wavelet Galerkin
schemes for the boundary element method.
Wavelet Galerkin schemes employ appropriate
wavelet bases for the discretization of boundary
integral operators. This yields quasisparse system
matrices which can be compressed to O(N_J)
relevant matrix entries without compromising the
accuracy of the underlying Galerkin scheme.
Herein, O(N_J) denotes the number of unknowns.
The assembly of the compressed system matrix
can be performed in O(N_J) operations. Therefore,
we arrive at an algorithm which solves boundary
integral equations within optimal complexity.
By numerical experiments we provide results which
corroborate the theory.
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Melandri, Giovanni. « Study of a novel solution to obtain controllable stiffness for beam-like elements ». Master's thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amslaurea.unibo.it/20196/.
Texte intégralRésumé :
La presente tesi tratta dello studio di concetti volti all'ottenimento di strutture meccaniche a rigidezza variabile per applicazioni in ambito di ricerca scientifica, in particolare per una futura applicazione in un robot aereo ad ala battente, al fine di studiare l'interazione tra ala elastica ed aria.
Vengono riassunti i metodi per ottenere rigidezza variabile ed, in seguito ad una fase di confronto basato su requisiti ed obiettivi di progetto, vengono scelte due soluzioni.
Il lavoro mostra che il concetto "sliding segments" funziona bene per una trave composta da un'asta interna ed un tubo esterno, entrambi formati da segmenti rigidi e flessibili alternati, di due materiali differenti. La rigidezza flessionale della trave varia grazie ad una traslazione dell'asta interna.
Viene inoltre mostrato come un'asta ed un tubo possono essere combinati per ottenere una trave rotante con diversi livelli di rigidezza flessionale in una direzione, riducendo gli effetti della flessione deviata.
Livres sur le sujet "3D beam element"
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T. Michaltsos, George, et Ioannis G. Raftoyiannis, dir. Bridges’ Dynamics. BENTHAM SCIENCE PUBLISHERS, 2012. http://dx.doi.org/10.2174/97816080522021120101.
Texte intégralRésumé :
Bridges’ Dynamics covers the historical review of research and introductory mathematical concepts related to the structural dynamics of bridges. The e-book explains the theory behind engineering aspects such as 1) dynamic loadings, 2) mathematical concepts (calculus elements of variations, the d’ Alembert principle, Lagrange’s equation, the Hamilton principle, the equations of Heilig, and the δ and H functions), 3) moving loads, 4) bridge support mechanics (one, two and three span beams), 5) Static systems under dynamic loading 6) aero-elasticity, 7) space problems (2D and 3D) and 8) absorb systems (equations governing the behavior of the bridge-absorber system). The e-book is a useful introductory textbook for civil engineers interested in the theory of bridge structures.
Chapitres de livres sur le sujet "3D beam element"
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Kostic, Svetlana M., Filip C. Filippou et Chin-Long Lee. « An Efficient Beam-Column Element for Inelastic 3D Frame Analysis ». Dans Computational Methods in Applied Sciences, 49–67. Dordrecht : Springer Netherlands, 2013. http://dx.doi.org/10.1007/978-94-007-6573-3_3.
Texte intégral
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Gebre, Tesfaldet, Vera Galishnikova, Evgeny Lebed, Evgeniya Tupikova et Zinah Awadh. « Finite Element Analysis of 3D Thin-Walled Beam with Restrained Torsion ». Dans Lecture Notes in Civil Engineering, 359–69. Cham : Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-10853-2_34.
Texte intégral
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Mohanty, Ankita Suman, et B. N. Rao. « 3D Non-linear Finite Element Analysis of a Naturally Corroded Beam ». Dans Recent Advances in Applied Mechanics, 151–59. Singapore : Springer Singapore, 2022. http://dx.doi.org/10.1007/978-981-16-9539-1_11.
Texte intégral
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Frissen, C. M., M. A. N. Hendriks et N. Kaptijn. « 3D finite element analysis of multi-beam box girder bridges – assessment of cross-sectional forces in joints ». Dans Finite Elements in Civil Engineering Applications, 421–27. London : CRC Press, 2021. http://dx.doi.org/10.1201/9781003211365-55.
Texte intégral
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Ansari, Reza, Amir Norouzzadeh et Hessam Rouhi. « Micromorphic Continuum Theory : Finite Element Analysis of 3D Elasticity with Applications in Beam- and Plate-Type Structures ». Dans Springer Tracts in Mechanical Engineering, 339–63. Cham : Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-63050-8_12.
Texte intégral
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Oñate, Eugenio. « 3D Composite Beams ». Dans Structural Analysis with the Finite Element Method Linear Statics, 150–232. Dordrecht : Springer Netherlands, 2013. http://dx.doi.org/10.1007/978-1-4020-8743-1_4.
Texte intégral
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Almeida, João P., António A. Correia et Rui Pinho. « Elastic and Inelastic Analysis of Frames with a Force-Based Higher-Order 3D Beam Element Accounting for Axial-Flexural-Shear-Torsional Interaction ». Dans Computational Methods in Applied Sciences, 109–28. Cham : Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-47798-5_5.
Texte intégral
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Szikrai, S., et E. Schnack. « Parallel Coupling of FEM and BEM for 3D Elasticity Problems ». Dans Boundary Element Topics, 243–64. Berlin, Heidelberg : Springer Berlin Heidelberg, 1997. http://dx.doi.org/10.1007/978-3-642-60791-2_12.
Texte intégral
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Maischak, M., et E. P. Stephan. « The hp-Version of the BEM with Geometric Meshes in 3D ». Dans Boundary Element Topics, 351–62. Berlin, Heidelberg : Springer Berlin Heidelberg, 1997. http://dx.doi.org/10.1007/978-3-642-60791-2_17.
Texte intégral
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Han, Guo-Ming, et Hong-Bao Li. « A Numerical Study for Convergence of a Classic 3D Problem Solved by BEM ». Dans Advanced Boundary Element Methods, 145–55. Berlin, Heidelberg : Springer Berlin Heidelberg, 1988. http://dx.doi.org/10.1007/978-3-642-83003-7_16.
Texte intégralActes de conférences sur le sujet "3D beam element"
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Tahmasebimoradi, Ahmadali, Chetra Mang et Xavier Lorang. « A Numerical Hybrid Finite Element Model for Lattice Structures Using 3D/Beam Elements ». Dans ASME 2021 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/imece2021-69119.
Texte intégralRésumé :
Abstract In this work, a numerically hybrid model is presented for the lattice structures to reduce the computational cost of the simulations. This approach consists of utilization of solid elements for the junctions and beam elements for the microbeams connecting the corresponding junctions to each other. To take into account the geometric defects, for each microbeam of the lattice structures, an ellipse is fitted to capture the effect of shape variation and roughness. Having the parameters of the ellipses, the lattice structures are constructed in Spaceclaim (ANSYS) using the geometrical hybrid approach. When the global response of the structure is linear, the results from the hybrid models are in good agreement with the ones from the 3D models. However, the hybrid models have difficulty to converge when the effect of large deformation and local plasticity are considerable in the BCCZ structures. For BCCZ lattice structures, the results are not affected by the junction’s size. This is also valid for BCC lattice structures as long as the ratio of the junction’s size to the diameter of the microbeams is greater than 2.
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Chiu, Rong, et Wenbin Yu. « Heterogeneous Beam Element Based on Timoshenko Beam Model ». Dans ASME 2022 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/imece2022-94187.
Texte intégralRésumé :
Abstract Traditional multiscale methods homogenize a beam-like structure into a material point in 1-D continuum with effective properties computed over a structure gene in terms of a cross-section or a 3D segment with spanwise periodicity. Such methods lose accuracy when dealing with real world beam-like structures usually not uniform or periodic along the spanwise direction. Thus, traditional multiscale methods cannot be rigorously applied to these cases. In our previous work, a new multiscale method was proposed based on a novel application of the recently developed Mechanics of Structure Genome (MSG) to analyze beam-like structures. Beam-like structures were homogenized into a series of 3-node Heterogeneous Beam Elements (HBE) with 18 × 18 effective beam element stiffness matrices, which were used as input for one-dimensional beam analyses. However, due to the shape function limitations, HBE could not handle transverse shear loads. In this work, the shape functions and the MSG theory are further modified to enable capabilities of HBE for transverse shear loads. Using the macroscopic behavior of the beam elements as input, dehomogenization can be performed to predict the local stresses and strains in the original structure. Two examples are used (a periodic composite beam and a tapered beam) to demonstrate the capability of this improved HBE.
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Le, Thanh-Nam, Jean-Marc Battini et Mohammed Hjiaj. « A NEW 3D CO-ROTATIONAL BEAM ELEMENT FOR NONLINEAR DYNAMIC ANALYSIS ». Dans 5th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering Methods in Structural Dynamics and Earthquake Engineering. Athens : Institute of Structural Analysis and Antiseismic Research School of Civil Engineering National Technical University of Athens (NTUA) Greece, 2015. http://dx.doi.org/10.7712/120115.3453.572.
Texte intégral
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Couturier, Philippe, et Steen Krenk. « General Beam Cross-Section Analysis Using a 3D Finite Element Slice ». Dans ASME 2014 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/imece2014-36721.
Texte intégralRésumé :
A formulation for analysis of general cross-section properties has been developed. This formulation is based on the stress-strain states in the classic six equilibrium modes of a beam by considering a finite thickness slice modelled by a single layer of 3D finite elements. The displacement variation in the lengthwise direction is in the form of a cubic polynomial, which is here represented by Hermitian interpolation, whereby the degrees of freedom are concentrated on the front and back faces of the slice. The theory is illustrated by application to a simple cross-section for which an analytical solution is available. The paper also shows an application to wind turbine blade cross-sections and discusses the effect of the finite element discretization on the cross-section properties such as stiffness parameters and the location of the elastic and shear centers.
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Hendriks, Max A. N., C. Marcel P. ’t Hart et Chantal M. Frissen. « 3D Finite Element Modeling of Buried Pipelines : On the Interaction of Beam Action of Pipelines and Cross Sectional Behavior ». Dans 2004 International Pipeline Conference. ASMEDC, 2004. http://dx.doi.org/10.1115/ipc2004-0735.
Texte intégralRésumé :
A common finite element modeling approach for buried pipelines is the combined use of beam and spring elements. Typical loads are soil settlements, temperature variations, internal pressures, neutral topsoil weight load and traffic loads. The beam elements represent the pipeline; assemblies of spring elements represent the surrounding soil comprising an elastoplastic bedding with friction. The choice for such finite element models is a pragmatic one. The models are relatively easy to construct and the analyses can be performed within reasonable calculation time on an average PC. From a mechanical point of view the problem of a buried pipeline subjected to subsidence, or an offshore pipeline subjected to sand waves, is of a full 3D nature. Beam elements and spring elements only partly incorporate full 3D effects. In practice the common finite element models are therefore enhanced to take into account 3D effects that would be otherwise omitted. A major point is the distinction between beam action and cross sectional behavior of pipes in straight and curved sections and their mutual interaction. This paper discusses the pros and cons of two possible finite element approaches which deal with this full 3D problem. In the final example it is illustrated that the two approaches gives similar results for the relatively simple problem of a buried bended pipe subjected to a temperature load and internal pressure.
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Bing, Yu, et Sun Xiaohan. « A Fast Quasi-3D Finite-Element Beam Propagation Method in Time Domain ». Dans 2007 Conference on Lasers and Electro-Optics - Pacific Rim. IEEE, 2007. http://dx.doi.org/10.1109/cleopr.2007.4391505.
Texte intégral
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Arshad, K., F. Katsriku et A. Lasebae. « Finite Element based Beam Propagation Method for 3D Wave Propagation in Troposphere ». Dans 8th International Conference on Advanced Communication Technology. IEEE, 2006. http://dx.doi.org/10.1109/icact.2006.206410.
Texte intégral
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Cosby, Austin, et Ernesto Gutierrez-Miravete. « Finite Element Analysis Conversion Factors for Natural Vibrations of Beams ». Dans ASME 2014 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/imece2014-37261.
Texte intégralRésumé :
The objective of this paper is to present results of a study designed to determine conversion factors to allow designers and analysts calculate natural frequencies of vibrating prismatic beams of arbitrary dimensions using simpler beam elements instead of expensive 3D solid elements. Prismatic beams subject to the most commonly encountered boundary conditions were modeled using beam elements and solid elements. The resulting natural frequencies were calculated and validated and the corresponding conversion factors were determined.
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Hassanpour, Soroosh, et G. R. Heppler. « Dynamics of a 3D Micropolar Beam Model ». Dans ASME 2014 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/detc2014-35453.
Texte intégralRésumé :
The development of a simplified micropolar beam model is presented and the governing dynamic equations for a micropolar beam deforming in 3D space, under different types of external loading and boundary conditions are derived. The dynamic equations are derived from Hamilton’s principle and the finite element method is used to provide numerical examples. The modal behavior of the developed micropolar beam model and the conditions under which the results of classical beam models will be recovered are presented.
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Smith, Mike C., Steve Bate et P. John Bouchard. « Simple Benchmark Problems for Finite Element Weld Residual Stress Simulation ». Dans ASME 2013 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/pvp2013-98033.
Texte intégralRésumé :
Finite element methods are used increasingly to predict weld residual stresses. This is a relatively complex use of the finite element method, and it is important that its practitioners are able to demonstrate their ability to produce accurate predictions. Extensively characterised benchmark problems are a vital tool in achieving this. However, existing benchmarks are relatively complex and not suitable for analysis by novice weld modellers. This paper describes two benchmarks based upon a simple beam specimen with a single autogenous weld bead laid along its top edge. This geometry may be analysed using either 3D or 2D FE models and employing either block-dumped or moving heat source techniques. The first, simpler, benchmark is manufactured from AISI 316 steel, which does not undergo solid state phase transformation, while the second, more complex, benchmark is manufactured from SA508 Cl 3 steel, which undergoes solid state phase transformation during welding. A number of such beams were manufactured using an automated TIG process, and instrumented with thermocouples and strain gauges to record the transient temperature and strain response during welding. The resulting residual stresses were measured using diverse techniques, and showed markedly different distributions in the austenitic and ferritic beams. The paper presents the information necessary to perform and validate finite element weld residual stress simulations in both the simple austenitic beam and the more complex ferritic beam, and provides performance measures for the austenitic beam problem.
Rapports d'organisations sur le sujet "3D beam element"
1
Ravazdezh, Faezeh, Julio A. Ramirez et Ghadir Haikal. Improved Live Load Distribution Factors for Use in Load Rating of Older Slab and T-Beam Reinforced Concrete Bridges. Purdue University, 2021. http://dx.doi.org/10.5703/1288284317303.
Texte intégralRésumé :
This report describes a methodology for demand estimate through the improvement of load distribution factors in reinforced concrete flat-slab and T-beam bridges. The proposed distribution factors are supported on three-dimensional (3D) Finite Element (FE) analysis tools. The Conventional Load Rating (CLR) method currently in use by INDOT relies on a two-dimensional (2D) analysis based on beam theory. This approach may overestimate bridge demand as the result of neglecting the presence of parapets and sidewalks present in these bridges. The 3D behavior of a bridge and its response could be better modeled through a 3D computational model by including the participation of all elements. This research aims to investigate the potential effect of railings, parapets, sidewalks, and end-diaphragms on demand evaluation for purposes of rating reinforced concrete flat-slab and T-beam bridges using 3D finite element analysis. The project goal is to improve the current lateral load distribution factor by addressing the limitations resulting from the 2D analysis and ignoring the contribution of non-structural components. Through a parametric study of the slab and T-beam bridges in Indiana, the impact of selected parameters on demand estimates was estimated, and modifications to the current load distribution factors in AASHTO were proposed.
2
SEISMIC PERFORMANCE OF SPATIAL STEEL BEAM-COLUMN CONNECTIONS. The Hong Kong Institute of Steel Construction, août 2022. http://dx.doi.org/10.18057/icass2020.p.125.
Texte intégralRésumé :
This paper presents a finite element analysis for spatial beam-column connections in steel frame to better understand the structural behavior of spatial connections. After the simulation and validation of experimental results, a total of 7 refined 3D models, including beam-to-column connections at different positions in the steel frame, were created and analyzed cyclically through the nonlinear finite element program ABAQUS to investigate the spatial coupling effect. The momentrotation relationships and TI index distribution across the width of beam flanges, were discussed in detail to elucidate the mechanical performance interaction between strong-axis and weak-axis connections. Results showed that there is obvious interaction between two beams in strong-axis or weak-axis connections, and the plane exterior connections has better hysteresis performance. While the interaction of strong-axis connection and weak-axis connection slightly affected each other’s hysteresis performance, and thus the coupling effect of spatial connections is not evident.
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SIMPLIFIED MODELLING OF NOVEL NON-WELDED JOINTS FOR MODULAR STEEL BUILDINGS. The Hong Kong Institute of Steel Construction, décembre 2021. http://dx.doi.org/10.18057/ijasc.2021.17.4.10.
Texte intégralRésumé :
Prefabricated modular steel (PFMS) construction is a more efficient and safe method of constructing a high-quality building with less waste material and labour dependency than traditional steel construction. It is indeed critical to have a precise and valuable intermodular joining system that allows for efficient load transfer, safe handling, and optimal use of modular units' strength. Thus, the purpose of this study was to develop joints using tension bolts and solid tenons welded into the gusset plate (GP). These joints ensured rigid and secure connectivity in both horizontal and vertical directions for the modular units. Using the three-dimensional (3D) finite element (FE) analysis software ABAQUS, the study investigated the nonlinear lateral structural performance of the joint and two-storey modular steel building (MSB). The solid element FE models of joints were then simplified by introducing connectors and beam elements to enhance computational efficiency. Numerous parameters indicated that column tenons were important in determining the joint's structural performance. Moreover, with a standard deviation (SD) of 0.025, the developed connectors and beam element models accurately predicted the structural behaviour of the joints. As a result of their simplification, these joints demonstrated effective load distribution, seismic performance, and ductility while reducing computational time, effort, and complexity. The validity of the FE analysis was then determined by comparing the results to the thirteen joint bending tests performed in the reference.
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ENERGY DISSIPATION OF STEEL-CONCRETE COMPOSITE BEAMS SUBJECTED TO VERTICAL CYCLIC LOADING. The Hong Kong Institute of Steel Construction, septembre 2022. http://dx.doi.org/10.18057/ijasc.2022.18.3.3.
Texte intégralRésumé :
The finite element (FE) software ABAQUS was used to establish a 3D FE model and perform a pseudo-static analysis of steel–concrete composite beams. With the validated model, the influences of several key parameters, including shear connection degree, force ratio, and transverse reinforcement ratio, on seismic behavior were investigated and discussed. In addition, the working performance of studs was analyzed. The FE analysis results show that the steel girder is the main energy dissipation component of the composite beam, and the energy dissipation of the steel girder is more than 80% of the total energy. The next is longitudinal reinforcement, followed by a concrete slab, the minimum proportion is the studs. Results show that the energy dissipation ratio of studs is less than 1% under the condition of the parameters. However, an increase in shear connection is beneficial to improve the energy dissipation of steel girders and rebars. Shear connection, force ratio, and steel girder width–thickness ratio are the major factors that influence bearing capacity and seismic behavior. Transverse reinforcement, section form, and stud diameter are the secondary factors. Finally, a seismic design for composite beams was established.