Mohammad Sherbaf Behtash - Department of Mechanical Engineering, Azarbaijan Shahid Madani University, Tabriz, Iran
Ali Ziaei Asl - Department of Mechanical Engineering, Azarbaijan Shahid Madani University, Tabriz, Iran

In this paper, effects of two co-axial defense holes on stress concentration factor (SCF) of a circular hole in a rectangular plate under uniaxial tension have been investigated by finite element method. For different geometrical parameters of defense holes such as, diameter (d) and distance of defense holes from the central hole (CC), SCF has been investigated. It has been concluded that defense holes can affect SCF of the circular hole in different manners, and it depends on CC and also diameter of defense holes. When defense holes are far from the central hole, SCF of the central hole and defense holes are affected very little. However, when defense holes get closer to the central hole, their effect on SCF of the central hole increases. Moreover, bigger defense holes have more effect on SCF of the central hole than smaller ones. Over all, defense holes, which are smaller than the central hole, conversely increase SCF of the central hole instead of decreasing it at a specific CC/D.

Stress concentration factor, circular hole, defense holes, finite element method