ME07 · Sem 4 · Structural analysis

Howe truss

Aim: Analyse a Howe truss, the mirror of the Pratt truss.

🧪 Live simulation🧊 Real-time 3D bench⚠ Simulated values, not physical measurements

🔬 Virtual lab

Starting the lab…

📘 Theory

A Howe truss has diagonals sloping outwards, putting them in compression and the verticals in tension: historically suited to timber diagonals with steel rods as verticals.

Method of joints: ΣFx = 0, ΣFy = 0

🧰 Apparatus (virtual)

Model truss
strain gauges

📝 Procedure

Run and compare diagonal forces with ME06
Read the vertical member forces
Change the height
Decide which truss you would choose for steel

Observations and result (kept on this device)

🎤 Viva questions

Why were Howe trusses used for timber bridges

Timber is strong in compression and the iron verticals took tension.

What decides the most economical height

Balancing chord forces against web member lengths.

🛡️ Safety

Virtual by default. Machine shops, CNC, presses and test rigs need instructor supervision, PPE and machine-specific safety training.