Buckling of Struts Lab Procedure

Step 1 of 5

Programming the Machine

The Shimadzu Machine gets its instructions (how fast to move/how much force to apply) from the Trapezium X software. You must make the "Method File" for the Trapezium X software.

Do the following:

Click the "Create new method" button Choose a single compression test, with polarity set to "Compression" and force direction "Down" Set the maximum load to 5000N, and max displacement to 150mm Make the test speed 1mm/min, and adjust the sampling rate to 100msec (every 10msec would create too many data points) Select 1 batch, 5 samples per batch Set the chart limits to be 0N-500N, and 0mm-5mm. This is the size of how large the software draws its initial graph Click "Test with this method" - you don't need to save the method file if asked by a pop-up

🎯 Visual Check Point

The Trapezium X software should now have loaded an empty graph, signifying it is ready to go.

Fixtures

A pinned end condition and a fixed end condition can be used. To start with we will do pin-pin conditions.

Do the following:

Check that the V shaped steel fixtures are fitted to the top and bottom arms of the machine Check you have the two "knife edge" pieces. These will rest inside the V shaped fixtures, which allow them to freely rotate Pick a strut to test

Getting the sample ready

Now we need to configure the sample in the machine before we start the testing

Do the following:

Using the Shimadzu panel buttons (On. Up. Down) raise the top arm to a distance a bit larger than the strut Put one of the knife-edge pieces onto each side of a strut Place the strut so that the knife-edges now rest within the V shaped fixtures. There may be a bit of an air gap Lower the top arm until it is nearly (but not touching) the top knife-edge Use the panel spin-wheel to carefully lower the loading arm removing any remaining air gap/slack. Keep an eye on the digital force reading....once that suddenly increases, stop! This means you are now touching Slowly back off using the spin-wheel until the Force is approximately zero again Zero the stroke and the force

🎯 Visual Check Point

What catches some people out is not activating the panel buttons. Make sure the green light is on next to the up/down buttons. If it's not, press the 'On' button a couple times.

Running the Test

Now you are ready to set the machine off to run the test

Do the following:

Press the green panel button It asks if you are ready.... press the green button again

🎯 Visual Check Point

Observe the graph being plotted on the laptop screen showing force applied and the displacement (stroke) of the machine

Recording and Processing the Data

You can now repeat all those previous steps, for each strut until you have tested them all for pin-pin end conditions.

Check your spreadsheet/labsheet. If it asks you to do more test with different materials, or with fixed end conditions then do those now after swapping the V shaped (pinned) fixtures for the...'fixed' fixtures.

Then return to the labsheet & spreadsheet which will guide you in what to do with your data.

🎉 Congratulations!

You have successfully completed the Buckling of Struts laboratory procedure!

Next Steps:

✅ Process your strut test data
✅ Compare experimental data to theoretical predictios for buckling capacity
✅ Learn about the limitations of the Euler buckling equation

🏗️ Buckling of Struts

🎯 Visual Check Point

🎯 Visual Check Point

🎯 Visual Check Point

🎉 Congratulations!