Campbell Scientific CR9000X Measurement and Control System User Manual

Page 214

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Section 6. Data Table Declarations and Output Processing Instructions

The next stress cycle to get counted would be the -300 to 100 cycle depicted
below. It would have an amplitude value of 400 and a mean value of -200, thus
a count would be added to bin 3. A new vector from 950 to 0 would be drawn.

CYCLIC STRESS

100

-500

450

-300

100

-500

-600

-400

-200

0

200

400

600

0

1

2

3

4

5

6

7

8

9

Peak Values

St

ress/

St

rai

n

Val

u

es

CYCLIC STRESS

100

-500

450

-500

-600

-400

-200

0

200

400

600

0

1

2

3

4

5

6

7

8

9

Peak Values

St

ress/

St

rai

n

Val

u

es

At this point, we are out of new data points, and we will assume that the Data
Table's output has been triggered. We would bring across the 100 and -500
points to finish off the output for the rainflow histogram. We would count a
stress cycle from -500 to 100 that has an amplitude value of 600 and a mean
value of -200, resulting in a count being added to Bin 3. We would then add
one last stress cycle from -500 to 450, with an amplitude value of 950 and a
mean value of -25. This count would go into bin 5.

CYCLIC STRESS

-500

450

-500

100

-500

-600

-400

-200

0

200

400

600

0

2

4

6

8

10

12

1

Peak Values

Stress/Strain Values

Starting

Point

4

The result of these counts is shown in the table below:

Amplitude Column Bin Ranges

Mean Range 0 to 200

200 to 400 400 to 600 600 to 800 800 to 1000

-500 to 0

BIN 1 :

0

BIN 2 :

0

BIN 3 :

2

BIN 4 :

0

BIN 5 :

1

0 to 500

BIN 6 :

1

BIN 7 :

0

BIN 8 :

0

BIN 9 :

0

BIN 10 :

0

The record stored to the Data Table would look something like:

Time Stamp, Record Number, 0,0,2,0,1,1,0,0,0,0

6-30

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