Experimental Procedures

Be sure to write down all of the dimension measurements for the beam you are using.

Set up the strain indicators with a quarter-bridge circuit and one axial strain gage and one transverse strain gage.

If using the lathe bed or lab tables

1. place the weight hanger on the beam (making sure it does not touch the lathe bed), and zero the strain indicators.

2. take strain measurements for 10 loads in 5 lb increments up to 50 lb.

3. With the gages on the top surface of the beam, the axial strain will decrease and the transverse strain will increase with increasing load because the top of the beam is in pure compression.  With the gages on the bottom surface, the signs will be reversed.

If using the TO beam tester

1. zero the strain indicators and the load readout.

2. turn the wheel to lower the load head and apply the load.

3. take strain measurements for 10 loads in approximately 500 lb increments up to 5000 lb.

If using the TO universal testing machine

1. place a piece of bar stock between the beam and the load head.

2. zero the strain indicators and the load readout while the load head is not in contact with the bar stock.

3. set the load range to 6000 lb.

4. always keep the load-head speed on slow.

5. press the "Lower" button to lower the load head and apply the load. You can raise the load head to decrease the load if needed.

6. the load knob has a dead spot, so it is hard to stop the load on even increments.

7. take strain measurements for 10 loads in approximately 500 lb increments up to 5000 lb.