By the end of this section, you should be able to . . . Draw shear force and bending moment diagrams correctly and efficiently . Use the sign of the bending moment to determine which portion of the beam is in tension and which is in compression . Positive bending moment . . . Upper fibers are in compression.
Lower fibers are in tension.
Negative bending moment . Upper fibers are in tension. Lower fibers are in compression. If diagram is linear at the crossing . . . Be able to use slope of diagram.