"uuid","repository link","title","author","contributor","publication year","abstract","subject topic","language","publication type","publisher","isbn","issn","patent","patent status","bibliographic note","access restriction","embargo date","faculty","department","research group","programme","project","coordinates"
"uuid:dcc86ada-842a-4a9a-8444-e9b1ca1ea8c3","http://resolver.tudelft.nl/uuid:dcc86ada-842a-4a9a-8444-e9b1ca1ea8c3","Size and Topology Optimization for Trusses with Discrete Design Variables by Improved Firefly Algorithm","Wu, Yue (Harbin Institute of Technology); Li, Q. (TU Delft Structural Design & Mechanics; Harbin Institute of Technology); Hu, Qingjie (Hangzhou Xiaoshan Urban Planning Institute); Borgart, A. (TU Delft Structural Design & Mechanics)","","2017","Firefly Algorithm (FA, for short) is inspired by the social behavior of fireflies and their phenomenon of bioluminescent communication. Based on the fundamentals of FA, two improved strategies are proposed to conduct size and topology optimization for trusses with discrete design variables. Firstly, development of structural topology optimization method and the basic principle of standard FA are introduced in detail. Then, in order to apply the algorithm to optimization problems with discrete variables, the initial positions of fireflies and the position updating formula are discretized. By embedding the random-weight and enhancing the attractiveness, the performance of this algorithm is improved, and thus an Improved Firefly Algorithm (IFA, for short) is proposed. Furthermore, using size variables which are capable of including topology variables and size and topology optimization for trusses with discrete variables is formulated based on the Ground Structure Approach. The essential techniques of variable elastic modulus technology and geometric construction analysis are applied in the structural analysis process. Subsequently, an optimization method for the size and topological design of trusses based on the IFA is introduced. Finally, two numerical examples are shown to verify the feasibility and efficiency of the proposed method by comparing with different deterministic methods.","","en","journal article","","","","","","","","","","","Structural Design & Mechanics","","",""
"uuid:f3cd1f7b-aeda-4c36-8d35-dfe8fb5fad60","http://resolver.tudelft.nl/uuid:f3cd1f7b-aeda-4c36-8d35-dfe8fb5fad60","Form-finding of shell structures generated from physical models","Li, Q. (TU Delft Structural Design & Mechanics; Harbin Institute of Technology); Su, Y. (Harbin Institute of Technology); Wu, Y. (Harbin Institute of Technology); Borgart, A. (TU Delft Structural Design & Mechanics); Rots, J.G. (TU Delft Structural Design & Mechanics)","","2017","Vector form intrinsic finite element is a recently developed and promising numerical method for the analysis of complicated structural behavior. Taking the cable-link element as example, the framework of the vector form intrinsic finite element is explained first. Based on this, a constant strain triangle element is introduced, and relevant required equations are deduced. Subsequently, the vector form intrinsic finite element is successfully applied to carry out form-finding of shells generated from physical models, such as hanging models, tension models, and pneumatic models. In addition, the resulting geometries are analyzed with finite element method, thus demonstrating that a dominant membrane stress distribution arises when the shell is subjected to gravitational loading.","form-finding; physical models; shell structures; structural analysis; vector form intrinsic finite element","en","journal article","","","","","","","","","","","Structural Design & Mechanics","","",""
"uuid:fc58f67c-e2d1-4b5e-ac4d-3ffa8c8fe205","http://resolver.tudelft.nl/uuid:fc58f67c-e2d1-4b5e-ac4d-3ffa8c8fe205","How to understand ' Structural Morphology'?","Li, Q. (TU Delft Structural Design & Mechanics; Harbin Institute of Technology); Borgart, A. (TU Delft Structural Design & Mechanics); Wu, Y (Harbin Institute of Technology)","","2016","Due to its wide range of related research contents and diversified research approaches, the term ‘Structural Morphology’ has not been clearly defined by the Structural Morphology Group (SMG) of the International Association for Shells and Spatial Structures (IASS), founded in 1991, although some scholars have given their own viewpoints. This paper presents a different way to understand the meaning of “Structural Morphology” and its connotations. Nowadays, numerical techniques have become the most important means to do research in the field of structural engineering, and they can assist in the design, analysis and optimization of structures by handling a large number of parameters. In this paper, we present a common conceptual scheme for these numerical analysis methods. The scheme classifies the parameters of the initial structural system into five categories and, with the aid of numerical analysis methods, leads to the structural performance of the final structure. Two simple numerical examples are shown to verify the rationality of the scheme. On this basis, a conceptual formula to describe 'Structural Morphology' is proposed, which contains the whole numerical analysis process, shows the goal of structural morphology and also suggests a suitable methodology. Moreover, since numerical form-finding and computational morphogenesis have become two main research foci of structural morphology, a basic introduction, methodology and some achievements related to each research focus are presented in this paper.","structural morphology; parameters; structural performance; structural form; mechanical behavior; numerical form-finding; computational morphogenesis","en","journal article","","","","","","","","","","","Structural Design & Mechanics","","",""
"uuid:89dbc441-5095-4b15-abe9-34bbba4165c2","http://resolver.tudelft.nl/uuid:89dbc441-5095-4b15-abe9-34bbba4165c2","An approach on form-diversity of free-form shells generated from numerical hanging models","Li, Q. (TU Delft Structural Design & Mechanics); Borgart, A. (TU Delft Structural Design & Mechanics); Wu, Y (Harbin Institute of Technology)","Kawaguchi, K. (editor); Ohsaki, M. (editor); Takeuchi, T. (editor)","2016","","form-finding; free-form shells; form-diversity; numerical hanging models","en","conference paper","IASS","","","","","","","","","","Structural Design & Mechanics","","",""
"uuid:34dd249e-600c-40cb-9850-0037f8485dfc","http://resolver.tudelft.nl/uuid:34dd249e-600c-40cb-9850-0037f8485dfc","The Vector Form Intrinsic Finite Element method and several other form-finding methods for general networks","Li, Q. (TU Delft Structural Design & Mechanics; Harbin Institute of Technology); Borgart, A. (TU Delft Structural Design & Mechanics); Wu, Yue (Harbin Institute of Technology)","","2015","Discrete networks is a kind of form-active structural system which actively change its shape under varying load conditions. And for this kind of structural system, form-finding is the initial and essential part in their design process. Before the computer age, people complete the form-finding process using physical models, while with the advances in computational techniques, the research has focused on the numerical form-finding methods since the 1960s. A brief discussion on several numerical formfinding methods is presented in this paper. Firstly, two relatively mature numerical method, Dynamic Relaxation method and Force Density method, are introduced conceptually. And then, a newly developed numerical method, the Vector Form Intrinsic Finite Element method, is presented in more detail. At last, with a replacement of the calculation of the internal force of the element which obeys the Hooke's Law by the product of the force density and the length of the element, two derived methods based on the above three methods are proposed in this paper. Moreover, several numerical examples of hanging networks are shown to illustrate the validity and characteristic of the VFIFE method and the two newly proposed derived methods.","form-finding; general networks; Dynamic Relaxation method; Force Density method; Vector Form Intrinsic Finite Element method; derived methods","en","conference paper","","","","","","","","","","","","","",""
"uuid:2cca6b39-e76f-4445-8c62-5cf46786aca6","http://resolver.tudelft.nl/uuid:2cca6b39-e76f-4445-8c62-5cf46786aca6","Form-finding of gridshells generated from hanging-chain models by using the Dynamic Relaxation method and the NURBS technique","Li, Q. (TU Delft Structural Design & Mechanics; Harbin Institute of Technology); Wu, Yue (Harbin Institute of Technology); Borgart, A. (TU Delft Structural Design & Mechanics)","","2015","Hanging models play an important role in shaping a structure since a very early age, and were favored by A. Gaudi, H. Isler, F. Otto and other architects or engineers. Nowadays, with the development of numerical analysis theory and computer technique, it is more accurate and convenient to simulate these physical models via numerical means. Based on the background, this paper presents a numerical form-finding method of gridshell structures generated from hanging-chain models by using Dynamic Relaxation method and the NURBS technique, which aims to obtain more complex structural forms with multiple control points.

This method uses global NURBS surface interpolation to describe the initial cable-net model passing through the given target points, which serve as the fitting points of the NURBS surface. The cable elements of the cable-net are not allowed to elongate after form-finding, and clearly, this kind of cable-nets belongs to geometrically unstable system, whose form-finding process of it has a very strong nonlinearity. To solve this problem, it uses the Dynamic Relaxation method, which can complete the form-finding of geometrically unstable systems but with some special sets, to get the equilibrium form of the hanging cable-net under the gravity. However, this structural form may no longer pass through the given target points, and then it introduces the inverse iteration method to adjust the coordinates of the fitting points of the NURBS, which actually means to find the initial structural form which after form-finding can just right meet the target requirements. At last, some numerical examples are presented to demonstrate the validity of the proposed method in this paper.","form-finding; gridshells; hanging-chain models; Dynamic Relaxation method; NURBS; inverse iteration method","en","conference paper","","","","","","","","","","","","","",""