Recent paper on the flattening deformation of metal columns

This paper presents a theoretical and
experimental study on lateral compression of square and rectangular metal
columns. Some theoretical relations are derived to predict the absorbed energy,
the specific absorbed energy and the instantaneous lateral load during the
lateral compression. Analytical relations are obtained in two stages: elastic
and plastic parts. In the plastic zone, the total absorbed energy by the column
is calculated, based on the energy method. Then, an analytical equation is
derived to predict the instantaneous lateral load. In the elastic part, the
instantaneous load is obtained by linear behavior assumption. To verify the
theoretical formulas, some lateral compression tests were carried out on square
and rectangular columns and the experimental results are compared with the
theoretical predictions which shows a good agreement. Also, based on the
experiments, effects of geometrical dimensions and material properties of the
columns on the energy absorption capability are investigated. The results show
that the absorbed energy by a column increases proportional to the column length.
Also, columns with the thicker wall has the higher specific absorbed energy and
so, rectangular columns with the thicker wall are the better energy absorbers
during the flattening process. Also, the absorbed energy increases when length
of the column edge which the load is applied along it decreases. Also, it is found
that the specific absorbed energy by the aluminum columns is higher than the brazen
ones and therefore, flattened columns with the high ratio of the flow
stress/density are the better energy absorbers.

This paper has been published in the journal of 'archives of civil and mechanical engineering':

http://dx.doi.org/10.1016/j.acme.2013.04.008