Commit e600ed55 authored by Alfonso Parra Rubio's avatar Alfonso Parra Rubio


parent 9c2e2e11
......@@ -28,13 +28,15 @@ The tests to determine the viability of any design will be:
# **Allowable values**. Testing official NP Swabs at CBA Instron
<img src="images/OffNPS.jpeg" alt="plot1" width="900"/>
In this section, results of all experiments will be posted and can be used to compare with any value obtained by any proposed design. With difficulty, we have been able to receive 4 samples. That's why it was not possible to make multiple times some tests to establish a mean value and a deviation.
## **Bending Test**
Tooling was designed to this purpose.
<img src="images/mount.jpeg" alt="plot1" width="1000"/>
......@@ -46,8 +48,8 @@ The official NP Swab mounted in the tooling looks like the following:
Results obtained for this test are:
<img src="images/npbend.png" alt="plot1" width="500"/>
![NP Bending](images/npbend.png)
Two clear region can be seen. The maximum load that this first linear slope reaches is 0.18N. Up to that it start growing linear but with a much higher slope until 1.2N value is reached.
......@@ -57,12 +59,14 @@ Two clear region can be seen. The maximum load that this first linear slope reac
This test consist on compressing the hairy tip of the swab. As we don't want to compress the main stick that holds the tip, the value of the thickness will be our criteria to stop the test.
The lay-up shows as follows here:
<img src="images/compressedNP.jpeg" alt="plot1" width="900"/>
The results are the following:
<img src="images/npcomptest.png" alt="plot1" width="500"/>
Exponential grow can be seen reaching a maximum value of 2.5N when reached the nominal thickness of the stick. Similar behavior has been seen with cotton swabs in this same test.
......@@ -74,12 +78,13 @@ An NP Swab has been submitted to an ultimate tensile stiffness until failure. Th
The lay-out of this is the following:
<img src="images/NPTenion.jpeg" alt="plot1" width="900"/>
And results are the following
<img src="images/nptensiontest.png" alt="plot1" width="500"/>
The swab has been able to deform 16mm. The marks of the clamping system were statics so the test is valid. Also, the deformation compared with another partner (after the natural shrink after breaking) is huge!
......@@ -90,7 +95,8 @@ The swab has been able to deform 16mm. The marks of the clamping system were sta
This test has been tricky due to our machine is only available to make linear displacements. I have designed and manufactured tooling to be used in tension but able to have a degree of freedom, the rotation along this same axis.
<img src="images/NPTension1.jpeg" alt="plot1" width="900"/>
The test is described as following: I have pre-tensioned the swabs into a 8N force. I have started a tension test in the instron with a feed of 0.1mm/min (almost nothing). I have been rotating and counting the tooling until the tension force dropped suddenly in the test. when this happens, we have broke internally the swab by this fatigue torsion caused.
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