Bøjemomentet

Bøjemomentet, also known as bending moment, is a fundamental concept in structural engineering and mechanics of materials. It represents the internal force that a structural element experiences when subjected to external forces that cause it to bend. Specifically, it is the sum of all moments acting on a cross-section of the element due to these external forces.

When a beam or other structural member is loaded, internal stresses develop within the material. These stresses can be categorized as tensile (pulling apart) and compressive (pushing together). Bending moment is directly related to these stresses. On the concave side of a bent member, the material is typically under compression, while on the convex side, it is under tension. The magnitude of the bending moment at any point along the member is a measure of the tendency for that point to rotate or bend.

The calculation of bending moment is crucial for designing safe and stable structures. Engineers use bending moment diagrams to visualize how the bending moment varies along the length of a structural element. These diagrams help identify the points of maximum bending moment, which are critical for determining the required strength of the material and the cross-sectional dimensions of the member to prevent failure. The unit of bending moment is typically a force multiplied by a distance, such as Newton-meters (Nm) or pound-feet (lb-ft).