Geoland Engineering

Drawing Sizes for permit Applications (BNBC -2020)

🧱 1. What is SFD (Shear Force Diagram)?

The Shear Force Diagram (SFD) shows how the shear force varies along the length of a beam.

Shear force = the internal force that tries to slide one part of the beam past another.

It changes where loads or reactions are applied.

📈 Rules / Features:

Load between points → slope in SFD = load intensity.

Point load → sudden jump in SFD.

UDL (Uniformly Distributed Load) → SFD is sloping line.

📉 2. What is BMD (Bending Moment Diagram)?

The Bending Moment Diagram (BMD) shows how the bending moment varies along the beam.

Bending moment = the internal turning effect due to loads.

It’s responsible for bending or sagging of the beam.

📊 Rules / Features:

Slope of BMD = Shear Force.

Where SFD = 0 → BMD is maximum or minimum.

For simply supported beams:

Positive bending → sagging.

Negative bending → hogging.