Rotating ESYS in a section in APDL around element center points

Milan94Milan94 Member Posts: 1

Hello all,

I am a new user of Ansys APDL and I have a problem which I can't find the solution for. I am using 2D solid PLANE182 elements to which I want to apply orthotropic material properties (composite material, for now just the global properties to keep things basic). For this the 1-coordinate of the element coordinate system (ESYS) should be in the direction of the primary material axis (x), and the 2-coordinate perpendicular to this.

The section I have a problem with is shown below. The horizontal and vertical section are fine (simply using LOCAL,0,x,y,z,-90 for the vertical section), but I can't get the ESYS correct for the curved section. I used LOCAL,1,x,y,z, to create a cylindrical coordinate system where x,y is the center point of the arc, but as shown this creates the 1-direction in the radial direction and the 2-direction in the tangential direction with respect to the center point. As you can see below all the ESYS in the curved section should be rotated by 90 degrees.

What could be a solution to this? When having the relevant elements selected, is there a command to rotate them individually? I assume not, because then the cylindrical coordinate system is not valid anymore. Else, is there maybe a way to create a *DO loop over all the elements and extract the current orientation (as shown below), create a new Cartesian LOCAL in the center of all elements, rotate the extracted ESYS orientation by 90 degrees and then using EMODIF,,ESYS,[new LOCAL #]? Or is there a simpler way? I am not yet very familiar with loops in APDL.

Any help is greatly appreciated!

Kind regards,

Element coordinate systems


  • Milan94Milan94 Posts: 3Member
    edited January 2019

    I found a solution that works quite well. Although nobody responded, I will leave this post up and will add my script below. Maybe someone will find it useful in the future.

    arcdiv = 16 ! number of arc divisions
    arccx = 10 ! global coordinate system arc x-centerpoint
    arccy = 12 ! global coordinate system arc y-centerpoint
    esysrot = -90         ! rotation of element coordinate system

    ESEL,s,CENT,y,0,arcdiv                         ! select elements only between chosen y-region
    LOCAL,100+i,0,arccx,arccy,,i*90/arcdiv-45/arcdiv ! create coordinate system for element selection
    ESEL,r,CENT,y,-0.05,0.05 ! select elements
    LOCAL,200+i,0,arccx,arccy,,esysrot+i*90/arcdiv-45/arcdiv    ! create coordinate system applied to ESYS
    EMODIF,all,ESYS,200+i         ! apply coordinate system to ESYS

  • altupakaaltupaka Posts: 2Member

    Thank you very much! It helped me a lot.

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