University of Surrey

Test tubes in the lab Research in the ATI Dance Research

A study of the efficiency of double layer grid structures.

West, F. E. S. (1967) A study of the efficiency of double layer grid structures. Doctoral thesis, University of Surrey (United Kingdom)..

Available under License Creative Commons Attribution Non-commercial Share Alike.

Download (5MB) | Preview


The research reported herein compares five types of grid structure of similar span and subject to the same external loading, each under up to four conditions of boundary restraint, designed by elastic theory to near their maximum span/weight efficiency. The structural medium used is tubular steel, the design standard BS 449. To facilitate design two devices (hitherto unreported by anyone else,, to the author's knowledge) have been developed, namely (a) accurate consideration of lattice beams as single merabers in structures; (b) automatic design by digital computer allowing for simple changes in geometry. The skeletal structures are analysed by stiffness method and other possible methods discussed, The possibility of applyig linear programming to the search for the most efficient structure is also dealt with. From the analyses the most efficient span/berth ratio for each boundary condition is suggested and the mode of load distribution, the effect of pattern, pattern intensification and the inclusion of edge beams are discussed. A model diagrid composed of lattice beams one direction and prismatic beams in the other, the chords of the former having the same second moment of area when considered as a Single section as that of the prismatic bean, has been tested and used to illustrate the fallacy of the common assumption made for such beams. The model was designed as a control to the derivation of lattice beam stiffness matrices mathematically, graphs and tables of which have been included in the report. Further work on load factor analysis, pattern effect and topology are suggested.

Item Type: Thesis (Doctoral)
Divisions : Theses
Authors : West, F. E. S.
Date : 1967
Depositing User : EPrints Services
Date Deposited : 09 Nov 2017 12:15
Last Modified : 15 May 2020 05:14

Actions (login required)

View Item View Item


Downloads per month over past year

Information about this web site

© The University of Surrey, Guildford, Surrey, GU2 7XH, United Kingdom.
+44 (0)1483 300800