Moment (bending)

What is Moment (bending) ?

Definition of Moment (bending) in Construction
The moment, is the amount of stress on a joint that is caused by a length of any construction element and the weight along or at the end of this component.

Similar to the elbow in the arm, the more the arm is holding at the end ( hand ) the more the moment is ( force ) within the elbow. Important in cantilevered and structures that are projecting. Again, as with the moment arm, the bending moment is extremely important to the design of any structure. Incorrect, or an unanticipated change in the moment arm, within a structure, or piece of equipment could result in the unanticipated increase in the moment on a connection which could cause failures.

The failures within the World Trade Center towers were caused in many cases by an increase in the moment on connections due to the intense heat of the flames. Once moments are changed within a structure, the transfer of forces to other elements, connection, components of the entire system become uncontrolled and can result in failure. Using the crane example, if a load is projected out from the pivot point of the crane beyond the design parameters of the crane, the moment force on the pivot point could cause this pivot to yield and fail. Many construction and industrial accidents are attributed to a moment that exceeded design and failed.