This paper presents a non-linear finite element procedure for shape finding of form structures and studies an approach wherein the engineer recognises formable curved surfaces focusing on the engineer's own imagination and creativity before turning to numerical analysis to assist in the design. With the investigation of a simple numerical method of locating geodesic lines, a convenient shape finding approach is presented. Another purpose of this paper is to present a method by which compression shell shapes can be obtained by inverting the loads on the tension shape obtained by loading a cable net system. This work parallels the physical models used by H. Isler for his work on thin concrete shells. The paper gives examples of the mesh shapes generated and the computer visualisation of several examples. It demonstrates that the computer modelling is a suitable alternative to the physical modelling process. The numerical results given show that the computer software is reliable, and provides the designer with a useful tool for membrane design.
Get full access to this article
View all access options for this article.
References
1.
OttoF.RaschB., Finding Form, Deutscher Werkbund Bayern, Edition A. Menges, 1955.
2.
Heinz Isler, New Shapes for Shells: Twenty Years After, IASS Bulletin Nr. 71/72, Madrid, 1979, 9–26.
3.
Heinz Isler, The Quality of Shell Design and Construction, Bulletin of the international association for shell and spatial structures., vol.32 (1991) n.2, 67–71.
4.
Heinz Isler, Concrete shells today, Proceedings of the IASS ASCE International Symposium. 1994, on Spatial, Lattice and Tension Structures Proc IASS ASCE Int Symp 1994, Publ by ASCE, New York, NY, USA, 820–836.
Heinz Isler, dipl. Ing., Burgdorf, Switzerland, Twelve Years Application of Bubble Shells, IASS CongressMexico1967.
7.
Heinz Isler, Recent Applications of Representative Shells, Congreso Internacional Sobre LA Aplicacion DE Estructuras LA Minares EN Arquitectura (1967: Mexico City, Mexico), 437–499.
Heinz Isler, Concrete Shells and Architecture, IASS Symposium on Membrane Structures and Space Frames, Osaka, September, 1986, 39–42.
10.
HeinzIsler. The Way to Shape, International symposium on innovative world of concrete (1993: Bangalore, India), Held Aug 30-Aep 3, 1993. Rotterdam: A.A. Balkema1993 (2V.), 147–162.
11.
HaugE.PowellG.H., Analytical shape finding of cable nets, Proceedings IASS symposium pacific Part II on tension structures and space frames, Tokyo and Kyoto, 1971, 83–92.
12.
HaugE.PowellG.H., Finite element analysis of nonlinear membrane structures, Proceedings IASS symposium Pacific Part II on tension structures and space frames, Tokyo and Kyoto, 1971, 165–175.
13.
SchekH. J., The force density method for formfinding and computation of general networks, Computer Methods in Applied Mechanics and Engineering, Vol. 3, 1974, 115–134.
14.
ArgyrisJ.AngelopoulosJ.BichatB.A general method for the shape finding of lightweight tension structures, Computer Methods in Applied Mechanics and Engineering, 3 (1974), 135–149.
15.
LewisW. J.LewisT. S., Application of Formian and Dynamic Relaxation to the Form-Finding of Minimal Surfaces, Journal of the International association for Shell and Spatial Structures, Vol. 37 (1996) n. 122.
16.
DayA. S.BunceJ. W., Analysis of cable network, Civil Engineering and Public Works Review, April 1970.
17.
BarnesM. R.Dynamic Relaxation Analysis of Tension Networks, Proceedings of International Conference on Tension Structures, London, April 1974.
18.
BarnesM. R., Application of Dynamic Relaxation to the Design and Analysis of Cable, Membrane and Pneumatic Structures, Proceedings of 2nd International Conference on Space Structures, Guildford, September 1975.
19.
BarnesM. R.Interactive Graphical Design of Tension Surface Structures, International Symposium on wide Span Surface Structures, Stuttgart, April 1976.
20.
BarnesM. R.ToppingB.H.V.WakefieldD.S., Aspects of Formfinding Using Dynamic Relaxation, International Conference on Slender Structures, London, September 1977.
21.
BarnesM. R., Computer-aided design of cable and membrane structures, with Applications to Expo 88 and DQDC, Riyadh, The First International Conference on Lightweight Structures in Architecture, Sydney, Australia, August 1986, 254–270.
22.
BarnesM. R.WakefieldW.S., Formfinding, Analysis and Patterning of Surface-Stressed Structures, First Oleg Korensky Memorial Conference, Queen Elizabeth II Conference Center, London, June 1988.
23.
BarnesM. R., Form-finding and Analysis of Prestressed Nets and Membranes, Computers & structuresVol. 80. No. 3, 1988, 685–695.
24.
BarnesM. R., Form and Stress Engineering of Tension Structures, Structure Engineering Review, Vol. 6, No. 3–4, 1994, 175–201.
25.
LewisW. J., The Efficiency of Numerical Methods for the Analysis of Prestressed Nets and Pin-jointed Frame Structures, Computers & Structures33, No. 3, 1989, 791–800.
26.
LewisW. J.LewisT. S., Application of Formian and Dynamic Relaxation to the Form-Finding of Minimal Surfaces, Journal of the International association for Shell and Spatial Structures, Vol. 37 (1996) n. 122.
27.
KiaYick Tan. The Computer Design of Tensile Membrane Structures. Ph.D. thesis, The University of Queensland, 1989.
28.
ArgyrisJ.H.ScharfD.W., Large Deflection Analysis of Prestressed Networks, Journal of the Structural Division, A.S.C.E., ST98, 1972, 633–654.
29.
MeekJohn L., Computer Methods in Structural Analysis, E & FN SPON1991.
30.
SalemM. H.TangJ. W.HarrisJ. C., Computer analysis of the world's largest membrane roof’, Proceedings of the ADINA Conference, August 1979, Report 82448–9, MIT, 487–509.
