Finding the center of the specimen

[[kl...]]

Hello there,

I am working on measuring some cracks with the help of the extensometers. In my calculation, I wanted to arrange the cracks' data from the middle of the specimen. Since the middle was not properly marked during the experiment, I am just drawing a line near the middle (approximately) and also manually measuring each crack distance with it. I was wondering if there is any option or way in the software that can help me find the middle of the specimen and show the crack distances from the center. 

As you can see from the picture above the middle should be around point 1. And the graph below is how i want to represent my analysis.

I would really appreciate some tips and help. Thank you in advance!

[[Th...]]

Hi kleo,

some ideas:

• use a fitting point over whole surface component to get the center of gravity (maybe not as good as you have missing data on the right)
• or (maybe the easiest way):
  • select all points of component 
  • create plane - fitting plane
  • create a point on the plane (center is automatically chosen)
• create a scripted point and use the bounding box of the surface component as base

Hope this helps,

Best regards,

Thorsten

[[kl...]]

Hi Thorsten,

Thank you very much for your help. I managed to find the center of the specimen. The other issue is measuring the crack distance from it. Is there another way except from the 2 point distance, which has to be done for each extensometer one by one?

 

Thanks again,

Kleo

[[Th...]]

Hi kleo, 

if you want all distance values you have to create and inspect all the distances to the extensometers.
But maybe this little script helps. 😉

# -*- coding: utf-8 -*-

import gom

def createAndInspectDist (p1, p2, dist_restr = ['xyz']):
	"""
	creates and inspects a distance between two given points p1 and p2
	dist_restr might be ["xyz","x","y","z"] 
	"""

	dist = gom.script.inspection.create_distance_by_2_points (
		point1 = p1, 
		point2 = p2)
	for distr in dist_restr:
		insp = gom.script.inspection.inspect_dimension (
			distance_restriction = distr, 
			elements=[dist], 
			nominal_value=0.0, 
			nominal_value_source='fixed_value', 
			type='distance')


KEYSTR = "Extens" #string which has to be included in the extensometername
EXTENSOMETERS = [ext for ext in gom.app.project.actual_elements.filter ('type', 'distance') if KEYSTR in ext.name]

CENTER = gom.app.project.actual_elements['Center']

DIST_RESTR = ["xyz","x","y","z"] # choose which ones are needed, here all directions are inspected

for ext in EXTENSOMETERS:
	p1 = CENTER
	p2 = {'point':ext.center_coordinate, 'target':ext}
	createAndInspectDist (p1, p2, dist_restr = DIST_RESTR)