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hello

We are studying on physical and mechanical properties of walnut. In this research the H5KS Hounsfield test equipment were used for the compression tests. It is important for us to compress walnuts until 30%maximum compression force reached after rupture. Based on preliminary studies,30% of maximum force after rupture, was chosen as an optimum point to stop tests.

The installed software is QMat version  3.69 . We used the Test Generator menu to generate test. after selecting wood as the material test , we choose the test wizard menu. In this menu , there are four tabs: Equipment setup, test steps, calculations and captions and save. After pass the Equipment setup and test steps and calculations  ,we see the captions and save tab. In this menu we want to change “down until break” set point  but we can’t do it. that is inactive. it seems that the break point as determined automatically.

We want to machine ignore the  breakage in the walnut shell and continue test  until fore reach 30% of maximum force after break. Please help us how to do it?

ANSWER

Thank you for your question

The method you are using is fine. The wizard in test generator allows you to tell the machine to move up (tensile) or down (compression) to a load/force, extension/strain, for a time or to break. Presumably you are choosing a user input of force which will correspong to 30% of the expected breaking load. The "dot" at the end of the row just means that when you have finished/saved and come to run the test in test zone, that if the sample breaks befor the target load has been reached the test will end. if you did not have this, the machine would keep on going until the limit has ben reached or the compression platens meet, which is undesirable.

Alternatively you could extrct a compression to load test from the database of over 1300 pre written tests and use this.

I hope this helps,

Regards,

David