Realistic modelling of tension fabric structures

Abstract

An accurate and reliable analysis capability for Tensioned Fabric Structures (TFS) constructed from plain weave PTFE coated glass-fiber fabric has been developed in this work. This analysis facility has in turn enabled an investigation of the behaviour and design of TFS to be conducted. The investigation has revealed deficiencies in current design procedures, which may ultimately result in compromised design, as these are founded on unrealistic overly simplistic design assumptions. The analysis facility developed is based on finite element analysis, and utilizes newly purpose developed elements and a specially developed material model for the fabric component of structures. The new elements and material model for fabric have been integrated into ADAPTIC (Izzuddin, 1991), an advanced nonlinear structural analysis program, allowing real structures to be analysed. The analysis facility developed enables analytical structural models to converge closer to physical reality than allowed by existing analysis facilities, which is attributed to the robust assumptions upon which the new analysis facility is based. As an example of such a robust assumption, fabric patterns are taken to be flat in their unstressed state, a realistic assumption ignored by typical current analysis capabilities for TFS. The accuracy and reliability of the developed finite elements and material model for the fabric are demonstrated to be high, through an appropriate number of verification examples and comparison of experimental test data, for the material response, against the modelled response. Confidence in the analysis facility is thus guaranteed. The work also contains a theoretical deliberation of the current design procedure, the integrated design procedure and a new design procedure called the combined design procedure. The combined design procedure, so called as it is based on both the current design procedure and the integrated design procedure, offers the prospect of considerable improvements to the overall design process for TFS.