The current interest in collapse characteristics brought about by
crashworthiness requirements ýas shown the need for a better
understanding and predictive capability for the thin walled open
section structures. In general three possible modes exist in which a
loaded thin walled open section column can buckle:
1) they can bend in the plane of one of the principal axes;
2) they can twist about the shear. centre;
3) or they can bend and twist simultaneously.
The following study was undertaken to investigate the general failure
of thin walled open section structures. A literature survey was
conducted and it prevailed that a basic fundamental theoretical study
was vital in describing the behaviour of thin walled structural
The following stages of theoretical study have been completed:
1) Formulation of the stiffness matrix to predict the generalised
force-displacement relationships assuming the small displacement
theory in the linear elastic range.
2) Formulation of the geometric stiffness matrix to predict the
buckling criteria under generalised loading and end constraints in
the linear elastic range.
3) Formulation of the compound coordinate transformation matrix to
relate local and global displacements or forces.
4) Preparation of the associated finite element computer program to
solve general thin walled open sections structural problems.
A Doctoral Thesis. Submitted in partial fulfillment of the requirements for the award of Doctor of Philosophy of Loughborough University.