Question

the cantilever bracket is bolted to a column with three m12 3 1.75 iso 5.8 bolts. the bracket is made from aisi 1020 hot-rolled steel. assume the bolt threads do not extend into the joint. find the factors of safety for the following failure modes: shear of bolts, bearing of bolts, bearing of bracket, and bending of bracket.

Answer 1

The factors of safety for the given failure modes of the cantilever bracket are shear of bolts, bearing of bolts, bearing of bracket, and bending of bracket.

Step-by-step explanation:

The factors of safety for the given failure modes are as follows:

• Shear of bolts: The shear force on each bolt can be calculated using the formula F = A * S, where F is the force, A is the cross-sectional area of the bolt, and S is the allowable shear stress for the material. The factor of safety is then calculated by dividing the ultimate shear strength of the bolt material by the calculated shear force.
• Bearing of bolts: The bearing force on each bolt can be calculated using the formula F = P * A, where F is the force, P is the pressure, and A is the bearing area. The factor of safety is then calculated by dividing the ultimate bearing strength of the material by the calculated bearing force.
• Bearing of bracket: The bearing force on the bracket can be calculated using the same formula as for the bearing of bolts. The factor of safety is then calculated by dividing the ultimate bearing strength of the material by the calculated bearing force.
• Bending of bracket: The maximum bending moment on the bracket can be calculated using the formula M = F * d, where M is the bending moment, F is the force, and d is the distance from the bolt to the center of the bracket. The factor of safety is then calculated by dividing the ultimate bending strength of the material by the calculated bending moment.