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15.09: High‐resolution modelling and design of steel structures
Author(s) -
Surampudi Bala A.V.,
Butler Martin A,
Swanson James A,
Rassati Gian Andrea
Publication year - 2017
Publication title -
ce/papers
Language(s) - English
Resource type - Journals
ISSN - 2509-7075
DOI - 10.1002/cepa.451
Subject(s) - finite element method , stiffness , nonlinear system , degrees of freedom (physics and chemistry) , residual , structural engineering , computer science , engineering , algorithm , physics , quantum mechanics
The art and science of structural engineering has always required a balance between predicting the demands on a structure and making sure that those demands can be met with the structure's strength and stiffness. Historically, analytical models have been used to predict demands and codified design equations have been used to predict strength. Over the past approximately 50 to 60 years, finite element analytical models have evolved from crude first‐order linear representations made up of dozens of degrees of freedom to sophisticated second‐order nonlinear models made up of hundreds of thousands of elements. With the ever increasing capability of personal computing and the ability to construct more and more sophisticated finite element models, new approaches to the design of steel structures that were once thought impossible are becoming realistic. State of the art a decade ago was to employ models constructed from discrete one‐dimensional elements based on nominal geometry and linear material behaviour. Influences and behaviours such as residual stresses, initial imperfections, buckling, fracture, and second‐order effects were addressed by codified design specifications, often in the form of tedious hand calculations. Exponential increases in computing power now permit entire structures to be represented using shell or solid elements and explicit modelling of influences such as residual stresses and initial imperfections. As a result, the balance between analysis and design can change. With modern sophisticated computer analyses, the balance can be shifted towards the analysis side of the equation leaving less work in the strength determination. With a model like the one described above, strength could be defined simply as yielding or as the development of a numerical singularity resulting from a loss of stiffness representing buckling or fracture. This paper outlines ongoing work towards developing guidelines for high‐resolution computer modelling of steel structures and rebalancing the treatment of phenomena between the analysis side and the design side of the equation.