Topology optimization methods modify the form of structures on base of stress distribution. The value of cross-sectional area or material density of the selected element is changed near to zero (e.g. SIMP). The take nodes out (TNO) method , wherein the connections among the elements are defined as springs, modifies the selected connection and therefore the contacted node similarly. Thus, by producing a disconnection, the method is able to change the connection's type (eg. brake an originally continuous beam structure with an internal hinge) or separate an element from the others. When all catching elements are disconnected at a point then the common node is out of work as well.

The TNO method was developed for bar structures. As an example a very simple and well known nine bar truss was presented [1,2,3]. The advantage of that simple structure is that the calculations can be easily controlled. The disadvantage is, that all loaded nodes are directly connected to all supported nodes, thus the number of the adequate nodes is almost given. The aim of this presentation is to give some concluding remarks to those early results and to show the application of the TNO method on a more complex connection network.

The new trusses are generated from hundreds of predetermined elements, having unsupported and unloaded internal joints. Thus the result produces a web of internal bars that assure structural stability. To control the results, the outside form, foundation and loadings of the structures are similar to the examples solved by SIMP in [4,5]. Finally the comparison and some concluding remarks are given.

1

Vásárhelyi A., Pomezanski V., "Topology Design of The Joint Types and Boundary Conditions of The Discretized Structures By Mathematical Programming", G.I.N. Rozvany and N. Olhoff (eds.), Topology Optimization of Structures and Composite Continua, Kluwer Academic Publishers, Netherlands, PP. 383-385, 2000.

2

Pomezanski V., "Optimization of Connections Between Structural Elements", 4th International Ph.D. Symposium in Civil Engineering, P. Schießl, N. Gebeken, M. Kenser, K. Zich (eds), Munich, Germany Sept. 19-21. Springer Verlag, Volume 2. pp. 130-135, 2002.

3

Pomezanski V., Vásárhelyi A., "Comparison of Support and Layout Optimization Methods", Proceedings of of The Fifth World Congress of Structural and Multidisciplinary Optimization, (WCSMO5) Lido di Jesolo - Venicia, Italy, 2003. Published by Schönenfeld & Ziegler, 2005.

4

Gaspar Z., Logo J., Rozvany G.I.N., "Addenda and Corrigenda...", Struct. Multidisc. Optim. 24, 338-342, 2002.

5

Pomezanski V., "Numerical Methods to Avoid Topological Singularities", Proceedings of the Eighth International Conference on Computational Structures Technology, B.H.V. Topping, G. Montero and R. Montenegro (eds.), Civil-Comp Press, Stirlingshire, UK, paper 211, 2006. doi:10.4203/ccp.83.211

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