To compare the experimental values of horizontal reaction with the simplified theory.
To provide the influence line for this reaction.
- 1 HSC5m/f Dial Gauge Assembly
- 1 HST501P Arch with Side Bracket*
- 1 HST502 Track Plate Assembly with Dial Gauge
- 1 HWH5 Reaction Load Hanger 2N
- 7 HWH4 Load Hanger 1N
- 1 HST405W Set of Weights
The parabolic arch has a uniform cross section 40 x 8mm and is made from mild steel. The span is 1m and the rise 0.2m. One hinged end is mounted on ball bearing rollers which run on a horizontal ground plate. Seven load hanger stirrups are attached to the arch at intervals of 0.125m (horizontally) across the span. A dial gauge indicates the horizontal displacement of the hinged end when load is applied to the arch. Provision is made for applying a horizontal thrust by adding loads to a hanger attached by a cord to the hinge. (Refer to Construction Appendix)
PART 1: HORIZONTAL REACTION FOR POINT LOAD AT 3/8 SPAN
- With a load hanger on one of the stirrups near the middle of the arch, the dial gauge datum reading is noted at the moving hinge.
- 10N increments of vertical load are applied to the hanger up to a total not exceeding 50N.
- As each increment is added apply loads to the horizontal reaction hanger to restore the dial reading to the datum value, thus complying theoretical condition of zero displacement of the hinges.
- The horizontal reactions are recorded in Table 1.
PART 2: THEORETICAL REACTION FOR A UNIFORM LOAD
- With load hangers on all seven stirrups has been note the dial gauge datum.
- Placing 5N on each hanger has stimulated a uniform distributed load.
- The horizontal reaction is found to give zero displacement of the moving hinge.
- The loading is increased to 10N per hanger and again the hinge is restored to its datum position.
- The results are recorded in Table 2.
PART 3: INFLUENCE LINE FOR H
- With all seven load hangers were still in the stirrups.
- The horizontal reaction is found for zero displacement as a 50N load is placed on each hanger in turn from left to right.
- The results are recorded in Table 3.