For the creep calculation, I have had a problem with Calculix results comparing with Abaqus results.
In this example, the Abaqus results for the PE seems seasonable. But the Calculix results for PE (CEEQ) are not right. I appreciate it very much if someone can have an answer. Is this a bug from Calculix?
The .INP file is following:
*HEADING
BASIC VERIFICATION OF CREEP (CREEP TEST)
*NODE
1,1.,0.
2,2.,0.
101,1.,10.
102,2.,10.
*NSET,NSET=BOT
1,2
*NSET,NSET=TOP
101,102
*NSET,NSET=LEFT
1,101
*ELEMENT,TYPE=CPS4
1,1,2,102,101
*ELSET,ELSET=DATTIM
1
*ELSET,ELSET=CREEPERS
1
*SOLID SECTION,ELSET=DATTIM,MATERIAL=A1
*MATERIAL,NAME= A1
*ELASTIC
20E6,.3
*PLASTIC
0.,0.
0.,10.
*CREEP,LAW=NORTON
2.5E-27,5.,-0.2
*BOUNDARY
BOT,2
LEFT,1
*STEP
** STEP 1 ----- ELASTIC LOADING
*STATIC
1.0E-7,1.0E-7
*DLOAD
1,P3,-20000.
*EL FILE,FREQUENCY=20
SDV,
S,
CEEQ
*NODE FILE, FREQUENCY=20
U
*END STEP
*STEP,INC=25000
** STEP 2 ----- CREEP TEST
*VISCO,CETOL=5.E-5
1.e-7,10000.,1.E-10
**PRINT,FREQUENCY=5,RESIDUAL=NO
*EL PRINT,ELSET=CREEPERS,FREQUENCY=20
SDV,S
CEEQ,
*EL FILE,ELSET=CREEPERS,FREQUENCY=20
SDV,S,CEEQ,
*NODE FILE,FREQUENCY=20
RF,U
*END STEP
By the way, The Calculix is not easy to get convergence solutions. It may need to change the CETOL or the initial step value for *VISCO.
Thanks.