ST154 · Deformation of Frames

Experimental apparatus for the deflection analysis of statically determinate and indeterminate plane frames

A rigid-cornered steel portal of either U-shape or S-shape is clamped at one end; the opposite end can be left free (statically determinate cantilever frame) or seated on a roller (statically indeterminate single-redundant frame). Point loads at arbitrary positions deform the frame; two dial gauges record the horizontal sway and vertical deflection. The apparatus gives the student a platform on which to apply first-order elastic theory, the principle of superposition and — above all — the principle of virtual work to compute both deformations and the redundant support reaction, then compare directly to the measured values.

Experiments

Elastic deformation of U-shaped and S-shaped frames under point loads
Statically determinate and statically indeterminate configurations
First-order elasticity theory — bending-moment diagram and elastic line
Application of the principle of superposition
Application of the principle of virtual work:
- virtual-force method — for deformations
- virtual-displacement method — for support reactions
Verification of the Maxwell–Betti reciprocal theorem
Horizontal thrust and side-sway in a portal frame
Comparison of calculated and measured deformations

Frames

Material steel, rectangular solid cross-section

Cross-section 20 × 10 mm

U-shaped portal edge length 600 × 600 mm

S-shaped frame edge length 600 × 600 mm

Supports

Clamping pillars 1 long + 1 short — for both determinate and indeterminate setups

Roller bearing 1 — introduces the redundant constraint

Load hook movable, positions along the frame

Measurement

Dial gauges 2 × 0…20 mm, graduation 0.01 mm

Load set

Weights 2 × 1 N hangers · 8 × 1 N · 6 × 5 N

Delivery

U-shaped and S-shaped frames
2 clamping pillars, 1 roller bearing
Movable-hook weight set; deflection roller with fixture; cable
2 dial gauges with brackets
Storage case with foam inlay, instruction manual

34 kg