by Xanthoman » Fri Nov 02, 2018 10:05 pm
I am not sure what you mean by simple bending moment...simple bending moment is just force,F, by distance,d, of moment arm. M=Fd. The way an object behaves has nothing to do with the moment as it deals with its own geometry, thus converting the effects of the moment, torsion, shear forces into stress. The greater the moment of inertia, I, the greater resistance to deformation geometrically. Material properties then come into play such as Young’s Modulus, E, (modulus of elasticity) which will dictate the deflection based on loading, P. Often the goal in design is to find a maximum acceptable deflection and then work to find the minimum deflection based on material and geometries involved and adjust to be within desired parameters. All these work down from total yield strength and making sure the combined stresses don’t deform the object or deflect it beyond the bounds. And I forgot the 1/12 value in my last equation for I of a rectangular cross section, I will edit that. I’m not sure exactly what you are referring, but I don’t recall anything being a simple square as you suggest...And without diagrams none of this mumbo-jumbo will mean anything to anyone who hasn’t taken a statics or strengths course at some point...haha