What is Shear Force in Structural Engineering?

Shear force is a type of internal force that acts perpendicular to the longitudinal axis of a structural member, such as a beam. It occurs when external loads cause the internal fibers of the material to slide against each other. Understanding shear force is critical for civil and mechanical engineers to ensure that components do not fail due to shearing stress.

How to Use This Shear Force Calculator

To use this tool, input the total length of the beam (Span), the magnitude of the concentrated point load, and the specific distance of that load from the left-hand support. The calculator will provide the reaction forces at both ends and the specific shear force values across the beam length with a detailed step-by-step breakdown.

Understanding the Calculations

The calculation follows standard static equilibrium principles. First, the reaction forces at the supports (RA and RB) are determined by taking moments about one end. Once the reactions are known, the shear force (V) is calculated by summing vertical forces from left to right. For a simply supported beam with a point load, the shear force remains constant from the left support until it reaches the point load, where it drops by the magnitude of the load, and then remains constant until the right support.

Frequently Asked Questions

What is the unit of Shear Force?
In the SI system, shear force is typically measured in Kilonewtons (kN) or Newtons (N). In imperial units, it is measured in pounds-force (lb) or kips.

Where is shear force maximum?
In a simply supported beam with a central point load, the shear force is maximum (and constant in magnitude) throughout the segments between the load and the supports.