Roller support

Definition

A roller support is a type of structural support that allows a beam or structure to rotate and move horizontally while resisting vertical loads. This flexibility enables structures to accommodate thermal expansion and other movements, making roller supports essential in various engineering applications.

5 Must Know Facts For Your Next Test

1. Roller supports only provide vertical reaction forces, meaning they do not resist horizontal forces or moments.
2. In static equilibrium analysis, roller supports simplify calculations by allowing free rotation of connected beams.
3. Roller supports are commonly used in bridges and frames to account for movement caused by temperature changes or other factors.
4. The reaction force at a roller support is always perpendicular to the surface on which it rests, typically acting upward.
5. Roller supports can be located at one or both ends of a beam, affecting the overall load distribution and behavior of the structure.

Review Questions

• How does the presence of roller supports influence the conditions for equilibrium of a structure?
  • Roller supports influence equilibrium by allowing rotation and horizontal movement while resisting vertical loads. This characteristic simplifies the calculations for static equilibrium since they only introduce vertical reaction forces into the analysis. By acknowledging this flexibility, engineers can determine how external loads impact the structure without complicating the calculations with additional constraints.
• Discuss the advantages of using roller supports in the design of frames and machines compared to fixed supports.
  • Roller supports offer significant advantages over fixed supports, especially in designs requiring movement or thermal expansion accommodation. Unlike fixed supports, roller supports allow rotation and horizontal displacement, which reduces stress concentrations and potential failure points in structures. This flexibility is particularly beneficial in frames and machines where dynamic loading conditions are prevalent, thus enhancing overall performance and durability.
• Evaluate the impact of using roller supports in statically indeterminate systems and how it affects deflection calculations.
  • In statically indeterminate systems, roller supports play a crucial role in simplifying deflection calculations. By allowing some degree of movement, these supports reduce internal stress distributions caused by external loads. When assessing deflection, engineers must consider the additional reactions introduced by roller supports but can leverage their rotational capabilities to create more accurate models. This approach leads to enhanced understanding and prediction of structural behavior under various loading scenarios.

Related terms

Pinned support: A pinned support allows rotation and horizontal movement but resists vertical and horizontal forces, providing stability to structures.

Fixed support: A fixed support prevents both rotation and translation, providing maximum stability and support for structures subjected to various loads.

Reaction forces: Forces that develop at supports due to the external loads acting on a structure, crucial for analyzing the equilibrium of structures.