Finite element models tend to overestimate the actual elastic response of structural timber connections. The paper shows how such overprediction relates to the modelling of the contact between fasteners and timber. The use of a control parameter called stiffness contact is proposed. After an experimental campaign, a method to determine it, based only on the geometry of a rectangular contact area, is proposed. The modeling adequacy is demonstrated by applying it to dowel embedment and moment resistant wood joint tests. The obtained results show good agreement with the experimental test series.

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.

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.

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.

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.

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.