Hello,

First, define a reference point for one end of the beam and define the moment for it, and fix the other end. Select the Total forces and moments (TF) variables from the Field Output Requests in the step module. Run the job. To plot the moment-curvature diagram, plot the TF of the reference point and UR3 (the UR number depends on your moment direction). Then, use "Operate XY data" and combine the two plots.

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If it is indeed a beam (length much bigger than the cross-section), then you can use a cross-sectional analysis such as VABS to obtain Moment-Curvature diagram directly.