DFLUX subroutine with flux depending on the angle of incidence

[GianlucaDZ]

Hi all,

it's my first post in this forum and I hope it's the right section. I've been reading a lot of threads for my research project and I believe it's time to ask some questions.
I'm a newbie with Abaqus and Fortran and I've been trying to use the subroutine DFLUX to apply a heat flux to my structure. The structure is basically a thin-walled open-section boom and the flux is the solar radiation that I'm considering always perpendicular for now. The absorbed flux depends on the angle of incidence, so that its intensity varies with a cosine law and some areas of the cross-section is obviously not exposed to the radiation. During the simulation the boom deforms and the area exposed change consequently and I'm struggling to implement this change on the angle of incidence condition.
I also have some doubts about the arguments of the subroutine: COORDS is just and array of dimension three and not a matrix containing all the coordinates, right? So, with the RETURN command the subroutine consider each point separately, am I interpreting right? Is it possibile to store the coordinates of every point of integration and only after that apply the angle of incidence conditon for the flux?
I hope I've been clear, it's not easy to explain without figures and I know that my English is quite poor.
Thanks in advance,

Gianluca

 

[GianlucaDZ]

So, basically the situation is explained in the picture. The flux direction is constant and its intensity on the structure varies according to cos(theta) and theta is defined by atan2(X,Y). For example in the first figure if theta is between 0 and pi/2 or between -pi/2 and pi, then the flux varies with the cosine law. As the structure deforms, the conditions on the angle changes accordingly, so that the zone interested by the flux is the one marked in red. However, with the subroutine I only manage to deal with one value of theta at a time and I cannot write a condition to change the flux. That's why I wonder if it's possible to obtain an array of theta somehow in order to define which area is subjected to the flux.
Any suggestions?

Thanks in advance.