- #1

Civilian2

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I have a beam, simply supported and I place 2 point loads on it (equidistant from either end). I measure a range of deflections (of the beam) using gauges as I increase the loads (always having the same load at each point). I measure these deflections at each point load and at the centre of the beam.

By using a BMD (or just by experience) we know that the moment will be constant inbetween the two point loads (i.e over the centre of the beam).

By knowing the difference in deflection between the point at the centre of the beam (max deflection) and the point under one of the loads, I can calculate the curvature of that constant moment section of the beam.

I can then plot the Moment verus the curvature (x-axis). I get a straight line.

Can someone explain to me in layman terms what I get? As in, what the slope of the graph represents?

I get a straight line for this plot. Looking at it, I think I'm looking at a similar thing to the elastic section of a stress strain curve, so I'm thinking that slope of the moment curvature plot is the elastic modulus of the beam. I'm unsure about this though.

Anyone able to explain? The significance of this slope?

Cheers in advance.