How to Get DAQ Assistant LabVIEW for Free with a Crack File
As mentioned earlier, the line density is the measure of the number of the lines on the output image. The line density of the cracks is more than that of the medium image because of the high concentration of eddy currents present in the cracks, making it difficult to remove the noise from the cracks. However, the higher value of line density was achieved with a low line tolerance. This was because of the poor-fitting cracks in the image. The line tolerance can be adjusted to improve the analysis of the cracks.
daq assistant labview download crack
The actual length for each of the features was computed by joining each pair of pixels on the crack axis by line segment. It is important to note that a valid crack axis should be perpendicular to the crack length. Otherwise, features on the crack axis would be considered as irrelevant. For this purpose, a perpendicularity filter was applied. Unfortuately, when features were rather flat on the crack axis, it led to potentially erroneous readings. This occurred with a portion of the cracks tested in this study, where the crack resulted in increased crack lengths even though the crack angle was not directed along the cracking vector. In these cases, the length of the crack axis was rescaled to be perpendicular to the crack direction.
Once the crack length was ascertained, a laser optical distance meter was placed on the surface where the crack was expected to have propagated. The actual crack lengths were marked on the surface of the test piece with a permanent marker at the distance of each crack location.
The crack parameters such as crack length, crack angle and crack propagation direction were subsequently quantified for each crack. For the crack angle, both the actual direction of the crack line and the direction perpendicular to it were measured and used to compute the actual crack angle.