Learning Forum

[Md_Salem]

Hello everyone,

I am trying to optimize the thickness of a piezo patch attached to a plate structure.

The geometry is done using DesignModeler. The optimization is done through design exploration in ANSYS 22R1.

I used the APDL code to assign a harmonic analysis of the Piezo patch under a voltage load. and here is a part of it:

ESEL,S,ENAME,,226

NSEL,R,LOC,Z,1e-3             !1e-3 is the initial thickness of the Piezo patch

D,ALL,VOLT,100                   ! 100 is the initial voltage load

and so on until the end of the code.

The problem that I faced is that I need to parametrize both thickness (initially 1e-3) and voltage (initially 100) such that [VOLTAGE/THICKNESS < known fixed value].

Would anyone help me with that problem?

Regards

 

[wrbulat]

I'll assume three things: (1) you parameterized the thickness of the piezo transducer in Design Modeler, (2) the APDL you provided is in a command object under the Analysis branch, and (3) you are applying the nonzero voltage on a planar surface (the maximum z coordinate of the piezoelectric body).

In this scenario you could use the following code:

esel,s,ename,,226 ! SELECT SOLID226 ELEMENTS

nsle                        ! SELECT NODES USED BY SELECTED ELEMENTS

*get,zmin,node,,mnloc,z  ! ZMIN = MIN Z COORD OF SELECTED NODES

*get,zmax,node,,mxloc,z ! ZMAX = MAX Z COORD OF SELECTED NODES

nsel,r,loc,z,zmax            ! RESELECT NODES AT Z=ZMAX

t_piezo=zmax-zmin       ! T_PIEZO = THICKNESS OF PIEZO (Z DIRECTION)

d,all,volt,arg1*t_piezo  ! SET VOLTAGE EQUAL TO ENTRY IN ARG1 FIELD (in Details) TIMES T_PIEZO

allsel    ! ENSURE ENTIRE MODEL IS SELECTED BEFORE SOLVING

I think you can paramaterize ARG1 by checking a box adjacent to the field in Details. I don't know DX, but I would think it's possible to define allowable limits on the values of parameters in the application. If so, you could set a limit on ARG1 (which equals VOLT/T_PIEZO) so that it cannot exceed this "known fixed value" you mentioned. I hope this helps!

Best,

Bill

 

[Md_Salem]

appreciated