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Hi

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?

 khosrow mohammadi

MS student of Agricultural Machinery Dept. Iran, tabriz university

ANSWER

Thank you for your question

i have looked at the settings you describe. The software allows you to set the first step ie move to: a user input of Force, an Extension or Strain or for a user input of time.

if you have chosen the first step to be User Input of Force and there is a "dot" underneath "Break Point" at the end of the row, this just means that when you come to run the program, the software will ask you to enter the force the machine is to compress to. However, if the test sample breaks before the machine gets to the target load, the test will end. if it didn't the machine would just carry on until it hit the bottom limit of the platens came together, which is undesitable. Incidentally, I assume you have set the first red arow to point downwards (compression)

As an alternatibve there are lots of pre-written tests in the database, some 1300 of them You could try searching under test type, compression for a suitable "compression to displacement" test.