A little innovation can be useful for challenges that our diverse clientele bring to us at TestResources.

A recent test of ingenuity arose when material researchers at a major university found they needed to test a unique sample. The researchers wanted to determine the stress-strain properties of small steel samples using a TestResources electromechanical test machine. They asked us to provide compression platens with a displacement gage.

Compression Fixture with ExtensometerThe challenge

The steel sample was only available in a small cylindrical form (500 micron thick with a diameter as large as 2 mm). The small sample size made for high point loading conditions that could easily deform standard platens.

The modulus of stiffness of the steel sample also proved to be problematic. The solid steel made high sample deflection or deformation measurement quality difficult to achieve. Ten percent sample strain on a 500 micron sample thickness requires a deflection measurement range of 50 microns. Modulus measurements are performed in the elastic range which then calls for accurate deflection measurements of 1 micron.

The test load was approximately 1500 pounds, so the third challenge involved the design of the compression fixturing to minimize sample misalignment.

Without a simple off the shelf solution, creativity became the key to our engineer’s design.

A creative solution

We engineered a special compression platen with a mini subframe fixture and with an integrated deflectometer. The fixture featured small compression platens so that the operator could visually see and adjust test samples.

A robust mini subframe helped maintain high and consistent alignment. The subframe included a side port that enabled the high resolution deflection gauge nose to be placed on axis directly over the test sample to consistently measure sample strain.

Our custom design provided a solution for innovators at a major university. With creative problem solving skills, we can solve even the most unique testing needs.

G813 Compression Test Fixture