Pages: 3 (629 words) /
Published: Nov 28th, 2011
• To determine the buckling load for a pinned ended strut.
Theory: • The critical buckling load, Pcr, for a pinned ended strut is given by; Pcr = п² EI / (L²) [pic]
1. Vernier Caliper 2. Specimen 3. Steel Ruler 4. Allen Keys 5. Digital indicator
1. Switch on the digital indictor and warm it up for at least 10 minutes.
2. Choose a specimen and measure its length. The width and thickness of the beam is 3 mm and 25 mm respectively.
3. Calculate the theoretical buckling load for a strut with pinned end condition. This is to ensure that the load applied to the strut does not exceed the buckling load.
4. Placed the grooved support into the slot of the attachment for the end conditions and tightened the side screws. Refer appendix for proper installation of the support.
5. Move the top platen upwards or downwards to bring the distance between the two supports closer to the length of the strut.
6. Press the tare button on the digital indicator to set the reading to zero.
7. Place the specimen in the groove of the top support.
8. While holding the specimen, adjust the jack so that the lower end of the specimen just rest in the groove of the bottom support. (If the distance between the two supports is slightly less than the length of the strut, turn the screw jack handle counter clockwise. If the distance between the two supports is slightly greater than the length of the strut, turn the screw jack handle clockwise.
9. Note the reading on the digital indicator. If the load is greater than 10 N turn the jack handle counter clockwise to bring it to less than 10 N.
10. Check the position of the dial gauge to ensure that it is at the mid length of the specimen. Set the dial gauge reading to zero.
11. Press the tare button to set the load indicator to zero.
12. Load the specimen in small increments by turning the screw jack handle slowly in the