Revistas
Revista:
JOURNAL OF BUILDING ENGINEERING
ISSN:
2352-7102
Año:
2022
Vol.:
60
Págs.:
105134
A study of axial¿moment interactions of bolted connections with double extended end plates is presented in this paper. Six connections, subjected to pure compression and flexural compression were tested for this purpose. After the experimental campaign, finite element models were developed and calibrated to accurately reproduce the experimental results. The models included initial imperfections to capture the possible buckling failure modes in the column web and the beam flanges. Moreover, the models with and without initial imperfections were compared for different sizes of the imperfection. Finally, the results obtained from the experimental and the computational models provided sufficient and adequate information to construct an axial-moment interaction curve for the tested joints.
Revista:
JOURNAL OF BUILDING ENGINEERING
ISSN:
2352-7102
Año:
2021
Vol.:
34
Págs.:
101925
The accurate simulation of steel structures requires a precise model of the joint behaviour. The methods proposed by the steel codes are based on either rotating springs or involved models of springs and rigid bars. In this article, a precise method to model the stiffness of 2D bolted steel connections is presented. First, the joint is accurately modelled using finite elements (FE). Then, the FE model is condensed to a cruciform element of 4 nodes (12 degrees of freedom) by constraining each side cross-section to a node located at its centre of gravity. Subsequently, forces are applied to each node to compute the flexibility matrix, which is then used to construct the stiffness matrix that is finally decomposed through singular value factorization. Following this procedure, a parametric study is conducted to build the training and validation sets of the metamodel. Kriging and Radial Basis Functions are chosen to metamodel and predict the stiffness matrices of the cases not included in the parametric study. Finally, steel structures are analysed with both complete finite elements and surrogate models, and the results are used to confirm the accuracy of the proposed method.
Revista:
JOURNAL OF CONSTRUCTIONAL STEEL RESEARCH
ISSN:
0143-974X
Año:
2020
Vol.:
168
Págs.:
106001
Revista:
ENGINEERING STRUCTURES
ISSN:
0141-0296
Revista:
CE/PAPERS
ISSN:
2509-7075
Año:
2019
Vol.:
3
N°:
3-4
Págs.:
331 - 336
Autores:
Costa, R. (Autor de correspondencia); Valdez, J.; Oliveira, S.; et al.
Revista:
ENGINEERING STRUCTURES
ISSN:
0141-0296
Año:
2019
Vol.:
188
Págs.:
277 - 289
This work presents the experimental assessment of the joint behaviour of five steel beam-to-column end-plate joint configurations to assess (i) the effect of minor axis end plate joints in the behaviour of major axis end plate joints, and (ii) the interaction of two minor axis end plate joints. The experimental tests were performed with true size cruciform sub-frames specimens with boundary conditions intended to simulate unbraced frames. The sub-fames, with one to three beams, were loaded introducing multiple 3D stress states in the column unstiffened web, causing an interaction between the mechanical behaviour of two or three major and minor axis joints. The interactions were assessed in terms of the moment-rotation relations of joints, connections and column web. It was found that, for the slenderness of the column web tested, (i) the minor-axis joints have only a relevant influence on the stiffnesses of the major-axis joints and (ii) that, when two minor axis joints are present, their mutual interation increases both their stiffness and strength.
Revista:
ENGINEERING STRUCTURES
ISSN:
0141-0296
Año:
2019
Vol.:
180
Págs.:
586 - 602
Torsional effects in joints need to be investigated in order to get a complete model of the joint and also to assess the real boundary conditions for the lateral torsional effects in the beams of structural frames. Phenomena such as: torsion, warping, lateral buckling, etc. are usually analysed assuming simplified boundary conditions, namely pinned or rigid, in frame analysis which can lead to erroneous and non-conservative results. With the aim of knowing the correct boundary conditions and real behaviour of the joints under torsion, an experimental program is carried out consisting of two tests of mayor axis doubled extended bolted end plate joints subjected to torsion about the axis along the length of the beam. These experimental results have allowed the validation of the finite element models carried out using the program Abaqus. Once the models are validated models, a parametric study is performed to assess the stiffness and resistance. This study also verifies that these joints behave in a semi-rigid way when compared with the torsional characteristics of the attached beam. Besides, the beam fails prior to the connection in most cases, and therefore, the joints can be assumed to behave as full-strength. Analytical expressions are proposed and checked with the FEM results proving that the proposed analytical formulae and the proposed mechanical model can predict the stiffness quite accurately, with an average error of 8.5%. Despite these joints can be classified as full-strength under torsion, an assessment of their resistance is done as well.
Autores:
Loureiro (Autor de correspondencia); Lopez; Reinosa; et al.
Revista:
JOURNAL OF CONSTRUCTIONAL STEEL RESEARCH
ISSN:
0143-974X
Beam-column steel joints usually have a semi-rigid behaviour, and this must be taken into account when carrying out a global analysis of the structure. Rotational springs at each side of the joint are commonly used to simulate this behaviour by means of the component method, but asymmetric welded beam-column steel joints are not included in the formulations of Eurocode 3. This research work proposes a new methodology to obtain the stiffness of welded asymmetrical beam-column steel joints, by means of a cruciform element of 4 nodes and 12 DOF, whose stiffness matrix is directly obtained by means of the meta-modelling of its elements using Kriging's method. The authors have carried out a wide study of 754 different asymmetric welded beam-column steel joints, whose finite element models have been analysed, and then the static condensation method has been used to obtain the equivalent condensed stiffness matrix (Kcond) of the cruciform element for the joints belonging to the training set. These matrices have been used to build the Kriging's model, and the rest of joints have been used for testing the method, which yields very good results. The use of meta-modelling methods to obtain the stiffness matrix of the joint is not only easier in its application than the component method, but it also leads to a formulation that is more accurate, and also takes into account the interactions between the different parts of the joint. (C) 2019 Elsevier Ltd. All rights reserved.
Revista:
JOURNAL OF CONSTRUCTIONAL STEEL RESEARCH
ISSN:
0143-974X
Año:
2019
Vol.:
156
Págs.:
242 - 251
Revista:
ADVANCES IN ENGINEERING SOFTWARE
ISSN:
0965-9978
Año:
2018
Vol.:
119
Págs.:
60 - 67
The Internet has increased its potential exponentially since its inception. This progress has been possible due to new standards and technologies, which have also allowed the development of a new type of web applications that are fully integrated in web browsers. In addition, structural analysis has become a collaborative task in which different people have to share information and outputs of analysis programs. In this paper, an effective and user-friendly web application for the collaborative analysis of steel joints is presented. The latest cutting edge technologies in the Internet are used to address fundamental issues inherent in structural analysis software such as visualisation, interaction, and structural evaluation. Specifically, WebGL API, part of the HTML5 standard, is used to solve the visualisation issues of the proposed application. A rigorous analysis of simple and rigid structural joints is performed according to the standards and criteria set by the Eurocode 3.
Revista:
JOURNAL OF CONSTRUCTIONAL STEEL RESEARCH
ISSN:
0143-974X
Año:
2018
Vol.:
140
Págs.:
208 - 221
Revista:
ENGINEERING STRUCTURES
ISSN:
0141-0296
Año:
2017
Vol.:
152
Págs.:
698 - 708
Revista:
ADVANCES IN ENGINEERING SOFTWARE
ISSN:
0965-9978
Año:
2017
Vol.:
112
Págs.:
136 - 146
Revista:
JOURNAL OF CONSTRUCTIONAL STEEL RESEARCH
ISSN:
0143-974X
Año:
2016
Vol.:
117
Págs.:
126 - 138
The behaviour of joints exerts an important influence on the overall performance of steel and composite structures. Modern codes, including Eurocodes 3 (EC3) and 4 (EC4), have included research advances for joint modelling to be used in common practice.
The method adopted in EC3 and EC4 to characterize the connections is the so-called component method. One of the most important components is the column web panel in shear, and its behaviour has been investigated thoroughly for the case of single rectangular shear panels arising when the beams have equal depths. However, the case of double column panels, formed by beams of different depths at each side of the column, has not been researched as much.
The aim of this paper is the characterization of the shear behaviour of rectangular double column panels attached to beams of unequal depths. In order to isolate the shear behaviour from other components, horizontally stiffened beam to column connections with commercial sections are experimentally tested. Also, finite element modelling and analysis is carried out to compare results. A mechanical model is proposed and a parametric study is performed by means of calibrated finite element models to characterize the different components, and define the analytical expressions for the stiffness and resistance of the proposed mechanical model. In addition, a cruciform finite element that captures the behaviour of the proposed mechanical model has been developed. This general cruciform element is also suitable for semi-rigid connections and can be used for global analysis of semi-rigid steel frames.
Revista:
JOURNAL OF CONSTRUCTIONAL STEEL RESEARCH
ISSN:
0143-974X
Año:
2015
Vol.:
108
Págs.:
60 - 69
Revista:
JOURNAL OF CONSTRUCTIONAL STEEL RESEARCH
ISSN:
0143-974X
Año:
2015
Vol.:
108
Págs.:
70 - 81
El «Cloud computing» describe un modelo innovador de prestación de servicios de forma centralizada usando Internet como medio de distribución. A día de hoy, el análisis de estructuras, que requiere grandes prestaciones de cálculo, no ha sido «migrado» al entorno de Internet, y suele ser desarrollado como software de escritorio en contra de la tendencia actual del mercado informático.
En este artículo se expone la arquitectura de una aplicación web para el análisis y diseño de estructuras, que consistirá en un paquete de servicios web como SaaS (Software as a Service) y estará compuesta por 4 módulos: un modelador 3D, un software de análisis, un software de diseño y un módulo CAD. También se exponen las herramientas actuales para su desarrollo como una aplicación integrada en el cloud.
Por último, se desarrolla una versión preliminar del módulo CAD que genera la documentación gráfica final en formato DXF. In recent years a considerable effort has been dedicated to improve the knowledge on the behaviour of semi-rigid steel connections by techniques such as the component method. One of the most important components of the connections is the column web under shear. This component has a well-known and defined behaviour for the case of rectangular panels, which results in internal beam to column joints with beams of equal depth. However, when the right and left beams have different depths the shear panel becomes trapezoidal, and the application of the formulation corresponding to rectangular panels produces inaccurate results. The results of different laboratory tests and finite element simulations have been shown in the companion Part I paper. Also a mechanical model was proposed to characterize its behaviour.
In the present work, the results of a wide parametric study, carried out by means of calibrated finite elements models, are shown. These results form the basis to characterize the different components, and define the analytical expressions for the stiffness of the proposed mechanical model. Additionally, a cruciform finite element has been developed that captures the behaviour of the proposed mechanical model. This general cruciform element is suitable for semi-rigid connections and can be used for the global analysis of semi-rigid steel frames. Finally, this approach is applied to several practical cases and the results are shown.
Revista:
ENGINEERING STRUCTURES
ISSN:
0141-0296
Año:
2015
Vol.:
98
Págs.:
241 - 250
Beam to column connections subjected to loads in the beam minor axis direction are usually considered either as pinned or rigid for both resistance and stiffness checks. This simplification is also assumed at the time of considering the stability of the column and the lateral buckling of the beams. However, as proven in the companion paper by means of laboratory tests and numerical simulations, these types of connections are actually semi-rigid and partial strength. The consideration of their real semi-rigid behavior can lead to a more accurate global analysis and, consequently, more optimized structures. Their behavior relies mainly on the characterization of the components acting on the T-stub under out-of-plane bending. In this paper a parametric analysis is performed to define the components involved. Analytical expressions are specified to describe each one of the components and the assembly process following a proposed mechanical model. The stiffness and strength that are obtained compare very satisfactorily with the experimental results of the T-stubs described in the companion paper.
Revista:
INFORMES DE LA CONSTRUCCION
ISSN:
0020-0883
Año:
2014
Vol.:
66
N°:
Extra-1
Págs.:
m001
El «Cloud computing» describe un modelo innovador de prestación de servicios de forma centralizada usando Internet como medio de distribución. A día de hoy, el análisis de estructuras, que requiere grandes prestaciones de cálculo, no ha sido «migrado» al entorno de Internet, y suele ser desarrollado como software de escritorio en contra de la tendencia actual del mercado informático.
En este artículo se expone la arquitectura de una aplicación web para el análisis y diseño de estructuras, que consistirá en un paquete de servicios web como SaaS (Software as a Service) y estará compuesta por 4 módulos: un modelador 3D, un software de análisis, un software de diseño y un módulo CAD. También se exponen las herramientas actuales para su desarrollo como una aplicación integrada en el cloud.
Por último, se desarrolla una versión preliminar del módulo CAD que genera la documentación gráfica final en formato DXF.
Revista:
JOURNAL OF COMPUTING IN CIVIL ENGINEERING
ISSN:
0887-3801
Año:
2013
Vol.:
27
N°:
2
Págs.:
159 - 166
nternet has increased its capacities and possibilities exponentially since its inception. This evolution has been possible because of new standards and technologies, like Web services. Structural analysis software has benefited from the Web supplying a new set of applications that provide highly intensive computational tasks in Web servers. However, recent and future improvements in the Internet will enable the development of a new type of structural analysis application fully integrated in Web browsers and not only deployed as Web services. This type of Internet application is formally known as a Web application. This paper presents the development of a 3D Web application for structural analysis, known as Structural Analysis Software as a Service, which is applied to 3D lattice girder structures. The latest cutting-edge Internet technologies are used to address fundamental issues inherent to structural analysis software such as visualization, interaction, and structural analysis. Specifically, WebGL API, part of the new HTML5 standard, is used to solve the visualization and interaction issues of the proposed application. This prototype only requires an Internet connection and an updated browser that supports these new standards. No additional plug-in or virtual machine interpreter is needed; thus, platform independence is guaranteed. DOI: 10.1061/(ASCE)CP.1943-5487.0000217. (C) 2013 American Society of Civil Engineers.
Revista:
ENGINEERING STRUCTURES
ISSN:
0141-0296
Año:
2013
Vol.:
48
Págs.:
55 - 69
Semi-rigid composite joints not only have the advantage of optimizing the use of the material, but also of providing lateral stiffness for sway frames. By means of semi-rigid joints, the lateral stability of the structure may rely on the stiffness and ductility of the joints, thus avoiding bracing systems. These advantages may even increase when the joints are designed as semi-rigid in both axes. In this case, the joint behaves in a three-dimensional way that includes an interaction between the major and the minor axis of the column.
In this paper, a new design for three-dimensional semi-rigid composite joint is proposed and tested in order to improve the behaviour and obtain the benefits of semi-rigidity when both the major and minor axis are included. Thus, the proposed design involves beams that are attached in a semi-rigid manner to both, the major and minor axes of the column.
The experimental program consists in one 3D semi-rigid composite internal joint under proportional loads, another internal joint subjected to non-proportional loads and one facade joint. These tests provide information as to whether the joints satisfy the requirements of the Eurocodes 3 and 4 (EC3 and EC4) in terms of ductility, stiffness and resistance. Also the possible interactions between the major and minor axes of the proposed joint that are caused by the loads and/or the geometry are studied.
Simultaneously, finite element modelling and analysis have been carried out and calibrated agains
Revista:
JOURNAL OF CONSTRUCTIONAL STEEL RESEARCH
ISSN:
0143-974X
Año:
2012
Vol.:
72
Págs.:
97 - 104
This paper deals with a component-based approach to model internal and external semirigid composite connections for the global analysis of frames. The method is based on a cruciform finite sized elastic-plastic joint element that takes into consideration its deformation characteristics including those of the panel zone as well as the left and right connections. In addition, all the internal forces that concur at the joint coming from the beams and columns and their respective eccentricities are also considered.
Revista:
ENGINEERING STRUCTURES
ISSN:
0141-0296
Año:
2010
Vol.:
32
N°:
2
Págs.:
385 - 396
Composite structures exhibit higher stiffness than steel structures with similar ductility, and also show better performance to fire action. These benefits have led to an increase in the number of composite structures built in high seismic areas. The main objective of the experimental tests explained in this article is to obtain useful data about the seismic behaviour of a composite semi-rigid joint with a double-sided extended end-plate. A series of monotonic and cyclic quasi-static tests was performed to characterize the behaviour of this joint type against seismic actions. The tests were performed on interior and on exterior joints, and they have provided useful data about the ductility of the joint, the amount of energy dissipated and the degradation effects.
This data was used to elaborate and calibrate a component-based model of the joint that is composed of two rotational springs, one for the shear panel behaviour and the other for the connection behaviour. This model is capable of simulating the joint behaviour and damage under cyclic loads with sufficient accuracy.
Revista:
ENGINEERING STRUCTURES
ISSN:
0141-0296
Año:
2010
Vol.:
32
N°:
2
Págs.:
397 - 408
The numerical model of the double-sided extended end-plate composite joint presented in Part I of this paper is used to evaluate the seismic performance of this joint when used in moment-resisting frames. For this purpose, three frames of different heights and spans were designed and analysed. Two pushover analyses, with uniform and modal lateral load, were performed to evaluate the ultimate capacity of the frame. Incremental dynamic analyses (IDAs) were also performed to evaluate the seismic properties of each frame using accelerograms that match three types of elastic response spectra. The data provided by the simulations has allowed us to obtain the behaviour factors of the composite frames that use this type of joint, and to ensure their improved behaviour under seismic actions.
Nacionales y Regionales
Título:
Nueva metodología para la caracterización directa y automática de uniones 2D viga-pilar, en acero y madera, mediante metamodelos
especializados basados en modos de deformación.
Código de expediente:
BIA2016-80358-C2-1-P
Financiador:
MINISTERIO DE CIENCIA E INNOVACIÓN
Convocatoria:
2016 MINECO EXCELENCIA. PROYECTOS I+D
Fecha de inicio:
30/12/2016
Fecha fin:
29/09/2020
Importe concedido:
77.440,00€
Otros fondos:
Fondos FEDER
Título:
Análisis basado en metamodelos para uniones de acero diseñadas mediante optimización topológica aplicada a la fabricación aditiva.
Código de expediente:
PID2020-113895GB-C32
Investigador principal:
Rufino Goñi Lasheras, Beatriz Araceli Gil Rodríguez
Financiador:
AGENCIA ESTATAL DE INVESTIGACION
Convocatoria:
2020 AEI PROYECTOS I+D+i (incluye Generación del conocimiento y Retos investigación)
Fecha de inicio:
01/09/2021
Fecha fin:
31/08/2024
Importe concedido:
56.628,00€
Otros fondos:
-
Título:
Soluciones Innovadoras para Estructuras de Madera
Contralaminada (Innovative Solutions for Cross Laminated Structures)
Código de expediente:
PCI2019-103591
Financiador:
MINISTERIO DE CIENCIA E INNOVACIÓN
Convocatoria:
2019 MINECO APCIN
Fecha de inicio:
01/03/2019
Fecha fin:
31/10/2022
Importe concedido:
109.000,00€
Otros fondos:
Fondos FEDER
