Transcript Document

Element Test using D_MOD2
PEER 2G02
By Dr. Neven Matasovic
I completed my analysis for the PEER 2G02 second assignment. As you know, input in D-MOD is an
acceleration time history. D-MOD can not accept shear strain (or stress) as an input and it does not allow
for specification of initial static shear stress (strain). The only way to check what D-MOD does in terms
of stress-strain behavior is to excite one element by a series of acceleration time histories (as you
provided in terms of shear strain time histories). Therefore, I:
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1.
converted the shear strain time histories you provided into the acceleration time histories. I did that
by arbitrarily assigning time step of 0.02 seconds and peak amplitude of approximately 0.9 g to each
shear strain time history you provided; and
2.
arbitrarily assigned a small amount of viscous damping (approximately 0.4%); mass and stiffness to
a single element and applied the above described, converted time histories to a (compliant) base of the
model.
3.
run the analysis using the modified MKZ model and monitored the results in terms of shear stress
and shear strain time histories.
Please note that, in fact, I did a non-linear single-degree-of-freedom system analysis. The results of my
evaluation follow plots of acceleration time histories used in the analyses. Please also note that I was
able to analyze only “spreadsheet” steps 1 and 3 as D-MOD does not allow for specification of initial
static shear stress (strain).
The results of my evaluations show that stress-strain model embedded in D-MOD strictly follows the
Masing rules.
As always, the D-MOD input/output files and related spreadsheets are available. Please let me know if
you require them,or anything else related to this exercise.
Sincerely,
Neven Matasovic
0 .0 0 0 3
0 .0 0 0 2
S tra in
0 .0 0 0 1
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-0 .0 0 0 1
-0 .0 0 0 2
-0 .0 0 0 3
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2 .5
T im e
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S tre ss
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0
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S tre ss
Symmetric Loading
Constant Amplitude
0
-2 0 0
-4 0 0
-6 0 0
-0 .0 0 0 3
-0 .0 0 0 2
-0 .0 0 0 1
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S tra in
0 .0 0 0 1
0 .0 0 0 2
0 .0 0 0 3
0 .0 0 0 3
0 .0 0 0 2
S tra in
0 .0 0 0 1
0
-0 .0 0 0 1
-0 .0 0 0 2
-0 .0 0 0 3
0
0 .5
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2 .5
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T im e
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S tre ss
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0
-2 0 0
-4 0 0
-6 0 0
0
0 .5
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T im e
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S tre ss
Symmetric Loading
Varying Amplitude
0
-2 0 0
-4 0 0
-6 0 0
-0 .0 0 0 3
-0 .0 0 0 2
-0 .0 0 0 1
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S tra in
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0 .0 0 0 2
0 .0 0 0 3
0 .0 0 0 3
Reverse Loading
0 .0 0 0 2
S tra in
0 .0 0 0 1
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-0 .0 0 0 1
-0 .0 0 0 2
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T im e
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-1 0 0
-2 0 0
-3 0 0
-4 0 0
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0
-1 0 0
-2 0 0
-3 0 0
-4 0 0
-0 .0 0 0 3
-0 .0 0 0 2
-0 .0 0 0 1
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S tra in
0 .0 0 0 1
0 .0 0 0 2
0 .0 0 0 3
0 .0 0 0 3
Reverse Loading
0 .0 0 0 2
S tra in
0 .0 0 0 1
0
-0 .0 0 0 1
-0 .0 0 0 2
-0 .0 0 0 3
0
1
2
3
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5
3
4
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T im e
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S tre ss
100
0
-1 0 0
-2 0 0
-3 0 0
-4 0 0
0
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2
T im e
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200
S tre ss
100
0
-1 0 0
-2 0 0
-3 0 0
-4 0 0
-0 .0 0 0 3
-0 .0 0 0 2
-0 .0 0 0 1
0
S tra in
0 .0 0 0 1
0 .0 0 0 2
0 .0 0 0 3
0 .0 0 0 3
Reverse Loading
0 .0 0 0 2
S tra in
0 .0 0 0 1
0
-0 .0 0 0 1
-0 .0 0 0 2
-0 .0 0 0 3
0
1
2
3
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5
3
4
5
T im e
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200
S tre ss
100
0
-1 0 0
-2 0 0
-3 0 0
-4 0 0
0
1
2
T im e
400
300
200
S tre ss
100
0
-1 0 0
-2 0 0
-3 0 0
-4 0 0
-0 .0 0 0 3
-0 .0 0 0 2
-0 .0 0 0 1
0
S tra in
0 .0 0 0 1
0 .0 0 0 2
0 .0 0 0 3
0 .0 0 0 3
Reverse Loading
0 .0 0 0 2
S tra in
0 .0 0 0 1
0
-0 .0 0 0 1
-0 .0 0 0 2
-0 .0 0 0 3
0
1
2
3
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5
3
4
5
T im e
400
300
200
S tre ss
100
0
-1 0 0
-2 0 0
-3 0 0
-4 0 0
0
1
2
T im e
400
300
200
S tre ss
100
0
-1 0 0
-2 0 0
-3 0 0
-4 0 0
-0 .0 0 0 3
-0 .0 0 0 2
-0 .0 0 0 1
0
S tra in
0 .0 0 0 1
0 .0 0 0 2
0 .0 0 0 3