Deflection

Definition

Deflection is a variation in position or shape of a structure or structural element due to the effects of loads or volume change, usually measured as a linear deviation from an established plane rather than an angular variation.

Purpose

The purpose of understanding and measuring deflection is to ensure that structures and their components can withstand applied loads without undergoing excessive deformation, which could compromise their safety and functionality. Engineers analyze deflection to design structures that maintain their integrity under load conditions.

Examples of Use

1. Building Floors: Calculating the deflection of floor beams to ensure they can support the weight of occupants and furniture without excessive sagging.
2. Bridges: Analyzing the deflection of bridge decks under the load of vehicles to ensure safe and reliable performance.
3. Cantilevered Structures: Assessing the deflection of cantilevered elements, such as balconies or overhanging roofs, to ensure they remain stable and secure.

Related Terms

• Load: The forces or other actions that result from the weight of building materials, occupants, and environmental effects.
• Structural Member: A component of a structure, such as a beam, column, or slab, that contributes to the structure's stability and strength.
• Elastic Deformation: Temporary deformation that disappears upon removal of the load causing it.

Notes

• Deflection limits are specified in building codes and standards to ensure structural safety and serviceability.
• Excessive deflection can lead to cracking, structural damage, and serviceability issues such as vibrations or misalignments.
• Structural engineers use various methods and tools, including finite element analysis, to predict and control deflection in design.