Final answer:
In a continuous beam, the maximum positive moment usually occurs at midspan, while negative moments typically occur over the supports.
Step-by-step explanation:
The maximum moment in a continuous beam occurs where shear forces change from positive to negative, which typically happens near the supports or under the loads depending on the beam's loading and support conditions. A negative moment, also referred to as a hogging moment, usually occurs over the supports in a continuous beam, where the underside of the beam is in tension. On the other hand, a positive moment, or sagging moment, typically happens at the midspan between supports, where the beam exhibits a convex curvature downwards, resulting in the top fibers of the beam being in tension.
It's important to note that moment distribution and other analytical methods are used to determine the exact location and magnitude of maximum moments in beams.