Blast Load Effects on Wide Flange Sections
(left) Effective plastic strain at 2 ms (HSLA 350) (center) Effective plastic strain at 6 ms (HSLA 350) (right) Rupture pattern observed on the web of the section in Blast test 1
Past studies of blast load effects on wide flange sections have been focused on major axis bending of the column, which results in global deformation and insignificant material loss in the section. The current project studies near field detonations on a wide flange section loaded about its minor axis of bending. Such a loading could possibly rupture the web, which could lead to an increase in the axial load in the flanges and jeopardize the axial load carrying capacity of the wide flange section.
A series of blast tests were conducted on wide flange sections (W14 X 53). Numerical simulations were performed to replicate the observed behavior. Several analytical models were considered for this purpose. First, Single Degree of Freedom (SDOF) analyses were performed using equivalent mass and stiffness coefficients. Equivalent blast pressures were applied to these SDOF models to assess their response. Second, a finite element model of the steel section was generated. Third, a finite element model coupled with the surrounding air mesh was modeled. Finally, an additional set of blast load scenarios were investigated by changing the system geometry and other configurations in the finite element model. These results were generated with the calibrated FE model. The findings of this project could be used to suggest blast resistant design strategies for wide flange sections.