Editing Tensile structure (section)

=== Pretension ===

'''Pretension''' is tension artificially induced in the structural elements in addition to any self-weight or imposed loads they may carry. It is used to ensure that the normally very flexible structural elements remain stiff under all possible loads.<ref>{{Cite journal|last1=Quagliaroli|first1=M.|last2=Malerba|first2=P. G.|last3=Albertin|first3=A.|last4=Pollini|first4=N.|date=2015-12-01|title=The role of prestress and its optimization in cable domes design|url=http://www.sciencedirect.com/science/article/pii/S0045794915002503|journal=Computers & Structures|language=en|volume=161|pages=17–30|doi=10.1016/j.compstruc.2015.08.017|issn=0045-7949|url-access=subscription}}</ref><ref>{{Citation|last1=Albertin|first1=A|title=Prestress optimization of hybrid tensile structures|date=2012-06-21|url=https://doi.org/10.1201/b12352-256|work=Bridge Maintenance, Safety, Management, Resilience and Sustainability|pages=1750–1757|publisher=CRC Press|doi=10.1201/b12352-256|isbn=978-0-415-62124-3|access-date=2020-06-30|last2=Malerba|first2=P|last3=Pollini|first3=N|last4=Quagliaroli|first4=M|doi-broken-date=2024-11-12|url-access=subscription}}</ref>

A day to day example of pretension is a shelving unit supported by wires running from floor to ceiling. The wires hold the shelves in place because they are tensioned – if the wires were slack the system would not work.

Pretension can be applied to a membrane by stretching it from its edges or by pretensioning cables which support it and hence changing its shape. The level of pretension applied determines the shape of a membrane structure.