Re: what's wrong with the UMAT subroutine

"Martin Bäker [email protected] [Abaqus]" <[email protected]> Fri, 7 Dec 2018 13:05:34 +0100
Newsgroups gmane.comp.mathematics.abaqus.user
Message-ID <20181207130534.05a3b13b@hopper>
don't know what's wrong with your routine, but it would be much simpler
to make Young's modulus dependent on a field variable and use
UFIELD/USDFLD to determine its value.

On Fri, 7 Dec 2018 10:00:57 +0800
"'[email protected]' [email protected] [Abaqus]"
<[email protected]> wrote:

> hi, 
> 
>     Thanks for your time and patience reading this email.
> 
>      Recently I've been trying to define a coordinate-dependent Young's modulus in a 2D plane stress model. I've write a user subroutine as below, but there's a error message ('Problem during compilation') when running the subroutine with ABAQUS/CAE. 
> 
>     Could anyone tell me what's going wrong with the subroutine?  Thanks again!  Frankey
> 
>       SUBROUTINE UMAT(STRESS,STATEV,DDSDDE,SSE,SPD,SCD,
>      1 RPL,DDSDDT,DRPLDE,DRPLDT,
>      2 STRAN,DSTRAN,TIME,DTIME,TEMP,DTEMP,PREDEF,DPRED,CMNAME,
>      3 NDI,NSHR,NTENS,NSTATV,PROPS,NPROPS,COORDS,DROT,PNEWDT,
>      4 CELENT,DFGRD0,DFGRD1,NOEL,NPT,LAYER,KSPT,KSTEP,KINC)
> C     
>       INCLUDE 'ABA_PARAM.INC'
> C      
>       CHARACTER*80 CMNAME
>       DIMENSION STRESS(NTENS),STATEV(NSTATV),
>      1 DDSDDE(NTENS,NTENS),DDSDDT(NTENS),DRPLDE(NTENS),
>      2 STRAN(NTENS),DSTRAN(NTENS),TIME(2),PREDEF(1),DPRED(1),
>      3 PROPS(NPROPS),COORDS(3),DROT(3,3),DFGRD0(3,3),DFGRD1(3,3)
>      4 JSTEP(4)
> C     VARIED YOUNG'S MODULUS WITH COORDINATE
>       PARAMETER (poiss = .3D0, ONE = 1.D0, TWO= 2.D0, YY=20000.D0)
>       X=COORDS(2)
>       young = YY*X
>       Lamda = young/(ONE - poiss*poiss)
>       DO I=1,NTENS
>        DO J=1,NTENS
>         DDSDDE(I,J) = 0.
>        ENDDO
>       ENDDO
>       DDSDDE(1,1) = Lamda
>       DDSDDE(2,2) = Lamda
>       DDSDDE(1,2) = Lamda*poiss
>       DDSDDE(2,1) = Lamda*poiss
>       DDSDDE(3,3) = (1.-poiss)*Lamda/TWO
>       
>       DO K=1,NTENS
>        DO L=1,NTENS
>           STRESS(K)=STRESS(K)+DDSDDE(K,L)* DSTRAIN(L)
>        ENDDO
>       ENDDO
>       
>       RETURN
>       END
> 
> 
> 
> 
> [email protected]


-- 
                   Priv.-Doz. Dr. Martin Bäker
                   Institut für Werkstoffe
                   Technische Universität Braunschweig
                   Langer Kamp 8
                   38106 Braunschweig
                   Germany
                   Tel.: 00-49-531-391-3065  
                   Fax   00-49-531-391-3058
                   e-mail <[email protected]> 
		   http://www.tu-braunschweig.de/ifw/institut/mitarbeiter/baeker
              	   http://www.scienceblogs.de/hier-wohnen-drachen