Premium
07.02: Distortional‐global interaction in lipped channel beams: Part I: Mechanics and elastic behaviour
Author(s) -
Martins André Dias,
Camotim Dinar,
Gonçalves Rodrigo,
Dinis Pedro Borges
Publication year - 2017
Publication title -
ce/papers
Language(s) - English
Resource type - Journals
ISSN - 2509-7075
DOI - 10.1002/cepa.192
Subject(s) - timoshenko beam theory , buckling , beam (structure) , bifurcation , structural engineering , displacement (psychology) , modal , mode (computer interface) , modal analysis , engineering , physics , mathematics , classical mechanics , finite element method , computer science , nonlinear system , materials science , quantum mechanics , psychology , polymer chemistry , psychotherapist , operating system
This work aims at presenting and discussing Generalised Beam Theory (GBT) numerical results concerning the elastic geometrically non‐linear behaviour of simply supported lipped channel (LC) beams under uniform major‐axis bending and experiencing distortional‐global (D‐G) interaction, making it possible to shed fresh light on the mechanics underlying this coupling phenomenon. Two LC beams geometries are considered, each exhibiting a different type of D‐G interaction, namely (i) “true D‐G interaction” (close global, M crG , and distortional, M crD , critical buckling moments), containing three critical‐mode initial geometrical imperfection shapes (two global, due to the lack of symmetry, and one distortional) and (ii) “secondary global‐bifurcation interaction – SGI” ( M crD « M crG ), containing a critical‐mode distortional initial imperfection. In order to clarify the surprising behaviour of the beam undergoing a SGI, an additional beam is analyzed, deemed to exhibit a “pure” distortional post‐buckling behaviour. The GBT results provide the evolution, along given equilibrium paths, of the beam deformed configuration (expressed in modal terms), relevant displacement profiles and modal participation diagrams. The knowledge acquired has visible impact on the development of rational design rules for CFS beams affected by D‐G interaction, a topic addressed in a companion paper.