SAMPE Journal - May/June 2020 - 28
FEATURE / FIBER OPTIC SENSING
Figure 8. Algorithm used to develop software for plotting principal strains.
Figure 9. Measurement comparison between each leg of fiber Rosette 1 with the matching FSG rosette leg on Coupon A.
The dotted black line indicates a linear trendline.
strains and their orientation across a 3D model of
the part. This methodology removed the tedious
and time-consuming task of analyzing each segment individually. The main steps in the software's
algorithm are shown below in Figure 8.
RESULTS
Individual Fiber Optic Strain Rosettes
In order to verify the accuracy of distributed fiber
strain measurements when laid out in rosette configuration, comparisons were carried out between
fiber and FSG rosettes. As the legs of each rosette
were laid out in the same direction, a representative plot of fiber strain versus FSG measurement
output is shown in Figure 9. This is of fiber Rosette
1 (R1) on coupon A and demonstrates a linear relationship for all 3 leg pairs throughout the loading
range. The slope, the zero offset, and the R2 values
are given in Table 1.
Fiber Rosette 2 on Coupon A was bonded incorrectly (the fiber sensor was lifted off the coupon
surface) and measurements from this rosette are
not included in the analysis below. Additionally, the
28
|
SAMPE JOURNAL
|
Table 1. Trendline slope, intercept, and R2 value, for measurement comparison between each leg of fiber Rosette 1 with the matching FSG rosette leg
on Coupon A.
Slope (x 1e5)
Intercept (µε)
R2
Coupon A; Fiber Rosette ε1
6.0021
-3.25
0.9999
Coupon A; Fiber Rosette ε2
5.4797
-2.00
0.9903
Coupon B; Fiber Rosette ε1
5.7243
-5.68
0.9949
FSG on coupon B demonstrated erratic measurements during Test 1, possibly due to an intermittent electrical short in either the gage or the wiring
which resulted in faulty readings and are also not
included in the analysis below. For all other rosettes, the principal strains, e1 and e2, and the orientation angle, j, were calculated for each rosette
on the two coupons. The maximum strain, e1, for
all tests is positive which is expected since the rosettes were located on the tension face of the bent
test article. The minimum strain, e2, is negative due
to Poisson effects.
The calculated principal strains from the fiber
M AY/J U N E 2 0 2 0
w w w. s a m p e . o r g
http://www.sampe.org
SAMPE Journal - May/June 2020
Table of Contents for the Digital Edition of SAMPE Journal - May/June 2020
Table of Contents
SAMPE Journal - May/June 2020 - Cover1
SAMPE Journal - May/June 2020 - Cover2
SAMPE Journal - May/June 2020 - Table of Contents
SAMPE Journal - May/June 2020 - 2
SAMPE Journal - May/June 2020 - 3
SAMPE Journal - May/June 2020 - 4
SAMPE Journal - May/June 2020 - 5
SAMPE Journal - May/June 2020 - 6
SAMPE Journal - May/June 2020 - 7
SAMPE Journal - May/June 2020 - 8
SAMPE Journal - May/June 2020 - 9
SAMPE Journal - May/June 2020 - 10
SAMPE Journal - May/June 2020 - 11
SAMPE Journal - May/June 2020 - 12
SAMPE Journal - May/June 2020 - 13
SAMPE Journal - May/June 2020 - 14
SAMPE Journal - May/June 2020 - 15
SAMPE Journal - May/June 2020 - 16
SAMPE Journal - May/June 2020 - 17
SAMPE Journal - May/June 2020 - 18
SAMPE Journal - May/June 2020 - 19
SAMPE Journal - May/June 2020 - 20
SAMPE Journal - May/June 2020 - 21
SAMPE Journal - May/June 2020 - 22
SAMPE Journal - May/June 2020 - 23
SAMPE Journal - May/June 2020 - 24
SAMPE Journal - May/June 2020 - 25
SAMPE Journal - May/June 2020 - 26
SAMPE Journal - May/June 2020 - 27
SAMPE Journal - May/June 2020 - 28
SAMPE Journal - May/June 2020 - 29
SAMPE Journal - May/June 2020 - 30
SAMPE Journal - May/June 2020 - 31
SAMPE Journal - May/June 2020 - 32
SAMPE Journal - May/June 2020 - 33
SAMPE Journal - May/June 2020 - 34
SAMPE Journal - May/June 2020 - 35
SAMPE Journal - May/June 2020 - 36
SAMPE Journal - May/June 2020 - 37
SAMPE Journal - May/June 2020 - 38
SAMPE Journal - May/June 2020 - 39
SAMPE Journal - May/June 2020 - 40
SAMPE Journal - May/June 2020 - 41
SAMPE Journal - May/June 2020 - 42
SAMPE Journal - May/June 2020 - 43
SAMPE Journal - May/June 2020 - 44
SAMPE Journal - May/June 2020 - 45
SAMPE Journal - May/June 2020 - 46
SAMPE Journal - May/June 2020 - 47
SAMPE Journal - May/June 2020 - 48
SAMPE Journal - May/June 2020 - 49
SAMPE Journal - May/June 2020 - 50
SAMPE Journal - May/June 2020 - 51
SAMPE Journal - May/June 2020 - 52
SAMPE Journal - May/June 2020 - 53
SAMPE Journal - May/June 2020 - 54
SAMPE Journal - May/June 2020 - 55
SAMPE Journal - May/June 2020 - 56
SAMPE Journal - May/June 2020 - 57
SAMPE Journal - May/June 2020 - 58
SAMPE Journal - May/June 2020 - 59
SAMPE Journal - May/June 2020 - 60
SAMPE Journal - May/June 2020 - 61
SAMPE Journal - May/June 2020 - 62
SAMPE Journal - May/June 2020 - 63
SAMPE Journal - May/June 2020 - 64
SAMPE Journal - May/June 2020 - 65
SAMPE Journal - May/June 2020 - 66
SAMPE Journal - May/June 2020 - 67
SAMPE Journal - May/June 2020 - 68
SAMPE Journal - May/June 2020 - Cover3
SAMPE Journal - May/June 2020 - Cover4
https://www.nxtbook.com/nxtbooks/sampe/journal_20241112
https://www.nxtbook.com/nxtbooks/sampe/journal_20240910
https://www.nxtbook.com/nxtbooks/sampe/journal_20240708
https://www.nxtbook.com/nxtbooks/sampe/journal_20240506
https://www.nxtbook.com/nxtbooks/sampe/journal_20240304
https://www.nxtbook.com/nxtbooks/sampe/journal_20240102
https://www.nxtbook.com/nxtbooks/sampe/journal_20231112
https://www.nxtbook.com/nxtbooks/sampe/journal_20230910
https://www.nxtbook.com/nxtbooks/sampe/journal_20230708
https://www.nxtbook.com/nxtbooks/sampe/journal_20230506
https://www.nxtbook.com/nxtbooks/sampe/journal_20230304
https://www.nxtbook.com/nxtbooks/sampe/journal_20230102
https://www.nxtbook.com/nxtbooks/sampe/journal_20221112
https://www.nxtbook.com/nxtbooks/sampe/journal_20220910
https://www.nxtbook.com/nxtbooks/sampe/journal_20220708
https://www.nxtbook.com/nxtbooks/sampe/journal_20220506
https://www.nxtbook.com/nxtbooks/sampe/journal_20220304
https://www.nxtbook.com/nxtbooks/sampe/journal_20220102
https://www.nxtbook.com/nxtbooks/sampe/journal_20211112
https://www.nxtbook.com/nxtbooks/sampe/journal_20210910
https://www.nxtbook.com/nxtbooks/sampe/journal_20210708
https://www.nxtbook.com/nxtbooks/sampe/journal_20210506
https://www.nxtbook.com/nxtbooks/sampe/journal_20210304
https://www.nxtbook.com/nxtbooks/sampe/journal_20210102
https://www.nxtbook.com/nxtbooks/sampe/journal_20201112
https://www.nxtbook.com/nxtbooks/sampe/journal_20200910
https://www.nxtbook.com/nxtbooks/sampe/journal_20200708
https://www.nxtbook.com/nxtbooks/sampe/journal_20200506
https://www.nxtbook.com/nxtbooks/sampe/journal_20200304
https://www.nxtbook.com/nxtbooks/sampe/journal_20200102
https://www.nxtbook.com/nxtbooks/sampe/journal_20191112
https://www.nxtbook.com/nxtbooks/sampe/journal_20190910
https://www.nxtbook.com/nxtbooks/sampe/journal_20190708
https://www.nxtbook.com/nxtbooks/sampe/journal_20190506
https://www.nxtbook.com/nxtbooks/sampe/journal_20190304
https://www.nxtbook.com/nxtbooks/sampe/journal_20190102
https://www.nxtbook.com/nxtbooks/sampe/journal_20181112
https://www.nxtbook.com/nxtbooks/sampe/journal_20180910
https://www.nxtbook.com/nxtbooks/sampe/journal_20180708
https://www.nxtbook.com/nxtbooks/sampe/journal_20180506
https://www.nxtbook.com/nxtbooks/sampe/journal_20180304
https://www.nxtbook.com/nxtbooks/sampe/journal_20180102
https://www.nxtbook.com/nxtbooks/sampe/journal_20171112
https://www.nxtbook.com/nxtbooks/sampe/journal_20170910
https://www.nxtbook.com/nxtbooks/sampe/journal_20170708
https://www.nxtbook.com/nxtbooks/sampe/journal_20170506
https://www.nxtbook.com/nxtbooks/sampe/journal_20170304
https://www.nxtbook.com/nxtbooks/sampe/journal_20170102
https://www.nxtbook.com/nxtbooks/sampe/journal_20161112
https://www.nxtbook.com/nxtbooks/sampe/journal_20160910
https://www.nxtbook.com/nxtbooks/sampe/journal_20160708
https://www.nxtbook.com/nxtbooks/sampe/journal_20160506
https://www.nxtbook.com/nxtbooks/sampe/journal_20160304
https://www.nxtbook.com/nxtbooks/sampe/journal_20160102
https://www.nxtbook.com/nxtbooks/sampe/journal_20151112
https://www.nxtbook.com/nxtbooks/sampe/journal_20150910
https://www.nxtbook.com/nxtbooks/sampe/journal_20150708
https://www.nxtbook.com/nxtbooks/sampe/journal_20150506
https://www.nxtbook.com/nxtbooks/sampe/journal_20150304
https://www.nxtbook.com/nxtbooks/sampe/journal_20150102
https://www.nxtbook.com/nxtbooks/sampe/journal_20141112
https://www.nxtbook.com/nxtbooks/sampe/journal_20140910
https://www.nxtbook.com/nxtbooks/sampe/journal_20140708
https://www.nxtbook.com/nxtbooks/sampe/journal_20140506
https://www.nxtbook.com/nxtbooks/sampe/journal_20140304
https://www.nxtbook.com/nxtbooks/sampe/journal_20140102
https://www.nxtbook.com/nxtbooks/sampe/journal_20131112
https://www.nxtbook.com/nxtbooks/sampe/journal_20130910
https://www.nxtbook.com/nxtbooks/sampe/journal_20130708
https://www.nxtbook.com/nxtbooks/sampe/journal_20130506
https://www.nxtbook.com/nxtbooks/sampe/journal_20130304
https://www.nxtbook.com/nxtbooks/sampe/journal_20130102
https://www.nxtbook.com/nxtbooks/sampe/journal_20121112
https://www.nxtbook.com/nxtbooks/sampe/journal_20120910
https://www.nxtbook.com/nxtbooks/sampe/journal_20120708
https://www.nxtbook.com/nxtbooks/sampe/journal_20120506
https://www.nxtbook.com/nxtbooks/sampe/journal_20120304
https://www.nxtbook.com/nxtbooks/sampe/journal_20120102
https://www.nxtbook.com/nxtbooks/sampe/journal_20111112
https://www.nxtbook.com/nxtbooks/sampe/journal_20110910
https://www.nxtbook.com/nxtbooks/sampe/journal_20110708
https://www.nxtbook.com/nxtbooks/sampe/journal_20110506
https://www.nxtbook.com/nxtbooks/sampe/journal_20110304
https://www.nxtbook.com/nxtbooks/sampe/journal_20110102
https://www.nxtbookmedia.com