Strain Gauge Application

These questions are what your research will answer. If YOU do it.

What have you investigated so far?

Where have you looked?

Saying you have Googled and failed ddoes not qualify you for free answers.

Do more research!

If at first trial you fail, try and try again (not using the same tactic). That could lead to (or sustain) insanity.

This ABS is to be forced out of the mold by something molten? really?

We used to do these tests with strain gauges and HP multi-pen paper recorders.

Nowadays you can work with data loggers and real time recording on computers.

Depending on the sort of tests and the nature, you can apply several gauges in the areas to measure. I would suggest to find a suitable glue with as little as possible impact on your project. I did not use ceramic types. I guess, the tests may work out as destructive for the strain gauges when the materials' distortion exceeds the gauge capacity.

Shazwan,

One question.

1. Why are you using ABS for an investment casting. Aren't you supposed to use wax? If you cover the ABS in the ceramic shell and put it in the oven, you are going to start a fire and make a sloppy mess in your oven!

One statement!

1. Your question is worded quite a bit like a homework assignment!

OK, I will bite. What really happens to the ABS during this process? Does it vaporize? Does it just melt, and run out of the mold under pressure from the injection of molten metal/hot stuff? Did you mean Fused Deposition Molding?

The answers to your questions would be the products of actual research in the field, not a one paragraph inquiry to an engineering blog.

Do you not have melt data on ABS? Why do you need a strain gauge at all?

The electrical resistance of a length of wire varies in direct proportion to the change in any strain applied to it. That's the principle upon which the strain gauge works.
The most accurate way to measure this change in resistance is by using the Wheatstone bridge. This is a balanced electrical circuit which displays any change on an indicator or feeds it into a process.

I hope you are also aware that any strain gage resistor exposed to such temperatures will also undergo a large change in resistivity (change in resistance) by temperature, and this would have to be compensated for (if that is even possible)?

The two separate effects could add to each other, resulting in a much larger measurement of "strain", than expected due to the heat problem.