What is a flitch plate girder?

What is a flitch plate girder?

• A. A wooden beam reinforced with steel plates on the sides
• B. A steel beam with a wooden top and bottom
• C. A laminated steel-wood composite beam
• D. Is made by sandwiching a piece of steel between two wooden beams

Answer: (D)

A flitch plate girder is a timber beam that has a steel plate placed between two wooden beams and bolted together to act as one unit. The steel plate takes the tensile forces in bending while the wood handles compression, producing a stronger, stiffer beam at a lower cost than solid steel or solid timber alone. This sandwich arrangement creates composite action between the steel and wood, which is the defining feature of a flitch plate girder. This differs from reinforcing a wooden beam with steel plates on the sides, or from a steel beam with wood on the top and bottom, or from a laminated steel-wood beam. The key idea is the steel plate being sandwiched between two wooden members to form a single, stronger girder.

A flitch plate girder is a timber beam that has a steel plate placed between two wooden beams and bolted together to act as one unit. The steel plate takes the tensile forces in bending while the wood handles compression, producing a stronger, stiffer beam at a lower cost than solid steel or solid timber alone. This sandwich arrangement creates composite action between the steel and wood, which is the defining feature of a flitch plate girder.

This differs from reinforcing a wooden beam with steel plates on the sides, or from a steel beam with wood on the top and bottom, or from a laminated steel-wood beam. The key idea is the steel plate being sandwiched between two wooden members to form a single, stronger girder.