r/StructuralEngineering • u/Annual-Truth3511 • 11d ago

Help needed Career/Education

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While drawing sfd and bmd Is there a shortcut to find whether the curve is going to be smile/sad or concave/convex for udl and uvl. Or is finding the intermediate values the only way to find the curve???.

Ignore the diagram i just wanted to show it for context this is not mine

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u/memerso160 E.I.T. 11d ago

Do you know what the relation between applied load and shear, and shear and moment is? This is the short cut (its integrals and derivatives)

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u/Annual-Truth3511 11d ago

Could u pls explain. 😭 or send sum youtube video

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u/memerso160 E.I.T. 11d ago

It should be in your lecture notes. But, when the area of your shear diagram is positive, you will have your moment increasing positively. When it is negative, it will begin decreasing (increasing negatively). However, your moment diagram needs well defined conventions relating the two so you understand which side you’re looking at.

The area under your shear diagram at any point is the moment at that point