You must use UMAT subroutine. It is a fortran subroutine where you must change
only the corps but not the subroutine name nor the variables names.
Uou have as input the values of differents variables at the last iteration and
the strain and temperature increments (called DSTRAN and DTEMP) and you must
calculate as output the tangent stiffness matrix, and the new value of strain
and stress vectors at current iteration.
Here is an exemple:
user coding to define DDSDDE, STRESS, STATEV, SSE, SPD, SCD
and, if necessary, RPL, DDSDDT, DRPLDE, DRPLDT, PNEWDT
From: Frank Richter <abaqus-master@...>
To: Abaqus@...; abaqus@... Sent: Tue, August 3, 2010 5:30:57 PM
Subject: Re: [Abaqus] Modelling a Shape Memory Alloy
seems you should have looked for a material model long before.
There is a built-in model for SMA in ABAQUS, but quite hidden.
> I am a Masters Student in the University of Manchester. Please I will need
> model a Nitinol spring in ABAQUS and I am stuck.I have been searching on
> the web
> and I have been seeing some stuff like UMAT or VMAT.I honestly dont know
> what to
> do as the deadline for the submission of my dissertation is fast
> approaching. I
> will need assistance in what to do in ABAQUS as I have already created in
> and imported it to ABAQUS.
> Awaiting your favourable responses.
> Akin Owoyele.
> [Non-text portions of this message have been removed]
Institute of Materials Science