Imperial College London
Emeritus Professor David Nethercot

Emeritus ProfessorDavidNethercot

Faculty of Engineering, Department of Civil and Environmental Engineering

Senior Research Investigator
 
 
 
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Contact

 

+44 (0)20 7594 6097d.nethercot

 
 
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Location

 

306Skempton BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Walport:2020:10.1016/j.istruc.2020.03.065,
author = {Walport, F and Gardner, L and Nethercot, D},
doi = {10.1016/j.istruc.2020.03.065},
journal = {Structures},
pages = {670--685},
title = {Equivalent bow imperfections for use in design by second order inelastic analysis},
url = {http://dx.doi.org/10.1016/j.istruc.2020.03.065},
volume = {26},
year = {2020}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - The stability of compression members is typically assessed through buckling curves, which include  the influence of initial geometric imperfections and  residual stresses. Alternatively, the capacity may be obtained more directly by carrying out either an elastic or an in elastic second order analysis using equivalent bow imperfections that account for both geometric  imperfections  and  residual  stresses.  For design  by second  order elastic analysis, following  the  recommendations  of  EN  1993-1-1,  the  magnitudes  of  the equivalent  bow imperfections can either be back-calculated for a given member to provide the same result as would be obtained from the member buckling curves or can be taken more simply as a fixed proportion of the member length. In both cases, a subsequent M–N (bending + axial) cross-section check is also required, which can be either linear elastic or linear plastic. For design by second order inelastic analysis, also referred to as design by geometrically and materially nonlinear analysis with imperfections (GMNIA)there are    currently no suitable recommendations for the  magnitudes of equivalent  bow  imperfections and, as demonstrated herein, it is not generally appropriate to use equivalent bow imperfections developed on the basis  of  elastic  analysis.  Equivalent  bow  imperfections  suitable  for  use  in  design  by second order inelastic  analysis  are  therefore establishedin  the  present  paper.The  equivalent  bow imperfections are calibrated against benchmark FE results, generated using geometrically and materially  nonlinear  analysis  with  geometric  imperfections  of  L/1000(L  being  the  member length)and residual stresses. Based on the resultsobtained, an equivalent bow imperfection amplitude e0= L/150 ( being the traditional imperfection factor set out in EC3), isproposedfor both steel and stainless steel elements and shown to yield accurate results.The reliability of  the  proposed  approach is assessed
AU  - Walport,F
AU  - Gardner,L
AU  - Nethercot,D
DO  - 10.1016/j.istruc.2020.03.065
EP  - 685
PY  - 2020///
SN  - 2352-0124
SP  - 670
TI  - Equivalent bow imperfections for use in design by second order inelastic analysis
T2  - Structures
UR  - http://dx.doi.org/10.1016/j.istruc.2020.03.065
UR  - http://hdl.handle.net/10044/1/79008
VL  - 26
ER  -
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