The following article published online at 10 July 2017, DOI:10.1007/s12209-017-0075-9, has been retracted by agreement between the authors and the journal’s editors. The retraction is due to duplicate publication, fig. 1, 2, 3, 4, 6, 7, 12, 14, 15, table 1, 2, 3, 4, 5, 6 in the paper had already been published in Steel and Composite Structures, Vol 21, no 1. The online version of this article contains the full text of the retracted article as electronic supplementary material.