With conventions that I adopted shown below
I drew roughly the shear force and bending moment diagram of a simply supported beam with concentrated load at the middle. Now while drawing I drew both shear force and bending moment diagram starting from the same end.
2)Then from the right end
But here how i found out the bending moment was by algebraically adding the areas under the shear force diagram starting from the one end and plotting them along the length of the beam towards the other end. Thus when finding the area under shear force diagram I took area under negative shear force as negative (i.e. negative bending moment).
Is this wrong? Because I am getting positive sign for bending moment when i start drawing from left end and negative sign for bending moment when I start from the right end. Although the shear force diagram is same from both ends.
I have noticed that I didn't use the sign convention I mentioned in the first place while drawing the bending moment. But I have seen in one of the lecture video that you can add up the shear force diagram areas algebraically and get the bending moment diagram easily .[link of the lecture]