Hello all, Probably a very simple question when you know how to do it. I am just struggling to find information that is correct.
So far:
Bolt @ 47°
Ultimate tensile strength = 509MPa
Shear Strength = 357MPa
Bolt Diameter = 17mm
F = 20KN
Divide the force of the bolt between the axis of the bolt and the perpendicular to the axis
i) along the axis = 20Cos47 =14.640KN
ii) along perpendicular to the axis = 20Sin47 = 14.627 KN
Area of cross section of the bolt = PiD2/4 = Pi172/4 = 226.980mm2
Direct tensile stress = DF/A = 13.640/226.980
= 0.06009KN/mm2
= 60.09N/mm2
= 60.09MPa (as 1Nmm2 = 1MPa)
Shear/tangential stress = SF/A = 14.627/226.980
= 0.06444KN/mm2
= 64.44N/mm2
= 64.44MPa
I know it is correct up to this point, the next bit I think I've done wrong and information on the equations seems to vary depending on the source.
Shear FoS = Ultimate tensile strength / shear stress = 509/64.44 = 7.90
Tensile FoS = Shear Strength / Direct tensile stress = 357/60.09 = 5.94
So is the factor of safety in operation = the lowest number? so 5.94??
Could anyone help me with this please, Thank you for looking.
So far:
Bolt @ 47°
Ultimate tensile strength = 509MPa
Shear Strength = 357MPa
Bolt Diameter = 17mm
F = 20KN
Divide the force of the bolt between the axis of the bolt and the perpendicular to the axis
i) along the axis = 20Cos47 =14.640KN
ii) along perpendicular to the axis = 20Sin47 = 14.627 KN
Area of cross section of the bolt = PiD2/4 = Pi172/4 = 226.980mm2
Direct tensile stress = DF/A = 13.640/226.980
= 0.06009KN/mm2
= 60.09N/mm2
= 60.09MPa (as 1Nmm2 = 1MPa)
Shear/tangential stress = SF/A = 14.627/226.980
= 0.06444KN/mm2
= 64.44N/mm2
= 64.44MPa
I know it is correct up to this point, the next bit I think I've done wrong and information on the equations seems to vary depending on the source.
Shear FoS = Ultimate tensile strength / shear stress = 509/64.44 = 7.90
Tensile FoS = Shear Strength / Direct tensile stress = 357/60.09 = 5.94
So is the factor of safety in operation = the lowest number? so 5.94??
Could anyone help me with this please, Thank you for looking.