Hello All,
I am new working with FEAP modeling simple viscoelasticity on a 2D mesh of 4x4 square elements with a constant stress applied on one side and restrained on the opposite side.
I have written the Input script below but the values of displacement and stress I obtain on the output are the same for all the time steps.
I have checked the values of “qi” (Viscoelastic Strain) as they enter the subroutine “viscoe.f” (../feap83dist/ver83/elements/material/small/viscoe.f) and they are always zero for all the time steps. I have also tried with different time steps and loop sizes.
Any suggestions to obtain actual viscoelastic behavior?
Thank you so much,
Juan G.
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FEAP * * Example_Viscoelasticity
25 16 1 2 2 4
MATErial,1
SOLId
PLANe STRAin
ELAStic ISOTropic 200.0e9 0.4
VISCoelastic term1 0.7 10
! Blank termination record
COORdinates ALL
1 0 0 0
2 0 0.25 0
3 0 0.5 0
4 0 0.75 0
5 0 1 0
6 0 0 0.25
7 0 0.25 0.25
8 0 0.5 0.25
9 0 0.75 0.25
10 0 1 0.25
11 0 0 0.5
12 0 0.25 0.5
13 0 0.5 0.5
14 0 0.75 0.5
15 0 1 0.5
16 0 0 0.75
17 0 0.25 0.75
18 0 0.5 0.75
19 0 0.75 0.75
20 0 1 0.75
21 0 0 1
22 0 0.25 1
23 0 0.5 1
24 0 0.75 1
25 0 1 1
! Blank termination record
ELEMents
1 1 1 1 2 7 6
2 1 1 2 2 3 8 7
3 1 1 3 4 9 8
4 1 1 4 5 10 9
5 1 1 6 7 12 11
6 1 1 7 8 13 12
7 1 1 8 9 14 13
8 1 1 9 10 15 14
9 1 1 11 12 17 16
10 1 1 12 13 18 17
11 1 1 13 14 19 18
12 1 1 14 15 20 19
13 1 1 16 17 22 21
14 1 1 17 18 23 22
15 1 1 18 19 24 23
16 1 1 19 20 25 24
! Blank termination record
BOUNdary restraints
1 0 1 1
6 0 1 0
11 0 1 0
16 0 1 0
21 0 1 0
! Blank termination record
FORCes
5 0 2.5e6 0.0
10 0 5.0e6 0.0
15 0 5.0e6 0.0
20 0 5.0e6 0.0
25 0 2.5e6 0.0
! Blank termination record
END
BATCh
DT,,1
TRANsient BACK
LOOP,,2
TIME
LOOP,,10
TANG,,-1
OUTP TANG
TANG,,1
NEXT
DISP ALL
STREss ALL
NEXT
END
STOP
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