What Is Static Engineering When it Comes to Beams & Motion?

Live Loads

• Engineers organize loads into live loads, which are dynamic forces that move, such as people occupying a structure, and static loads, which are loads that remain the same, such as the weight of structural elements. Beams are engineered to withstand all loads, which include the weight of the beam itself and other static, structural weights. They are also engineered to withstand an estimated range of potential live loads, such as the combined force of a dozen people walking across the floor and an 85-mph wind transferring load to the beam through exterior walls and rafters.

Static Loads

• Static loads are forces that do not fluctuate. One way to think of static forces is to think of the forces exerted on a structure if there were no live loads, such as occupants, wind or snow accumulated on the roof. When a beam is engineered, conceptually, it can be designed to withstand static loads and live loads plus a margin of safety.

Moment of Force

• A moment of force is an important concept in static engineering of beams and other structural members, such as trusses. It is the tendency of a force to exert torsion, twisting an element around an axis. It describes the dynamics of a lever. In addition, a moment of force can be thought of as latent energy; the lever doesn't have to actually move, it only has to have the mechanical potential and tendency to actuate the lever.

Negating Moments of Force

• Structural members such as beams are configured so they negate all moments of force with an opposing force plus enough additional strength to withstand any conceivable live load. This is especially apparent in a web truss where there is one angled truss member, then another, inverse member counteracting the moment of force of the first member, and so on. In a beam, tension or other engineered forces counteract moments of force with enough additional strength to meet all structural requirements.