I understand the sign convention for bending moments: positive moments cause com

Question

I understand the sign convention for bending moments: positive moments cause compression in the top of the plate, tension in the bottom (like a cup), negative is opposite (upside down cup). Do I maintain that convention in equilibrium equations, or go back to the old CCW +, CW -? Bottom line, I am just missing something, and I need someone to walk me through this. I picked an example out of my book, a column buckling problem the author explains thoroughly, and yet I cannot see how he ended up with the signs for this moment equation at a distance x from the base:

M = M0 + P*(-v) = P*e - P*v (11-45)

No matter how I look at it, it seems like those moments should be additive, not opposite. Please see attached and HELP!

I understand the sign convention for bending moments: positive moments cause compression in the top of the plate, tension in the bottom (like a cup), negative is opposite (upside down cup). Do I maintain that convention in equilibrium equations, or go back to the old CCW +, CW -? Bottom line, I am just missing something, and I need someone to walk me through this. I picked an example out of my book, a column buckling problem the author explains thoroughly, and yet I cannot see how he ended up with the signs for this moment equation at a distance x from the base: M = M0 + P*(-v) = P*e - P*v (11-45) No matter how I look at it, it seems like those moments should be additive, not opposite. Please see attached and HELP! In sections 11.3 and 11.4 we analyzed ideal column in which the axial loads acted through the centroids of the cross section. Under these conditions. The columns remains straight until the critical loads are reached. After which bending may occur.

Explanation / Answer

yeah the moments should be additive.i verified for the other part of the beam too .the answer should be M= -pe -p*v .may be its a
printing mistake.

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