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Shape optimization of radiating plate
Posted 16.04.2013, 18:07 GMT-4 Geometry, Mesh, Optimization Version 4.3a 1 Reply
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Dear all,
I'm currently optimizing the shape of a vibrating plate in an closed hollow cylinder filled with air to get an as straight as possible wavefront. I model it 2D axisymmetric and make use of solid mechanics and pressure acoustics in the frequency domain.
My plate is drawn as an rectangle and I only want the top line of the rectangle to be optimized, however now my whole shape (top and bottom line) of the rectangle are changed equally. Which is logic because I set a prescribed mesh displacement in z direction, but I don't know how to do it another way. I tried an parametric curve, but then the geometry and mesh aren't updated.
What I did:
- Build my geometry, add material and configure the pressure acoustics and solid mechanics module correctly
** The geometry of the plate, which I try to optimize, is a rectangle created with 4 linear Bézier polygons.
- Next I defined an displacement of the plate in z direction as a variable.
** Name: dz, expression: q1*sc1*sin(2*pi*s). Here q1(defined later) is the optimization variable and sc1 (defined as global parameter) is a scaling factor (in this case sc1=2)
- I also defined an objective function, which I tested by changing some variables and shape by hand.
- Next I added the optimization module to my model. I added my objective function as global objective. For global control variables I defined q1 with an lower (-1) and upper bound(1) and an initial value of 0.
- After that I added Deformed Geometry to my model. I selected all the solid mechanics. I added "Free deformation" to the part I want to optimize. To the boundaries of the part that I want to optimize I added "Prescribed mesh displacement" with dz as prescribed mesh displacement in z direction.
- At last I added a frequency domain study where I disabled the stationary solver and added an optimization solver.
Can someone explain me how to optimize only the top line of the rectangle and keep the bottom and sides fixed?
Thanks in advance.
Greetings Nick
PS the attachment is an overview of the geometry and the materials.
I'm currently optimizing the shape of a vibrating plate in an closed hollow cylinder filled with air to get an as straight as possible wavefront. I model it 2D axisymmetric and make use of solid mechanics and pressure acoustics in the frequency domain.
My plate is drawn as an rectangle and I only want the top line of the rectangle to be optimized, however now my whole shape (top and bottom line) of the rectangle are changed equally. Which is logic because I set a prescribed mesh displacement in z direction, but I don't know how to do it another way. I tried an parametric curve, but then the geometry and mesh aren't updated.
What I did:
- Build my geometry, add material and configure the pressure acoustics and solid mechanics module correctly
** The geometry of the plate, which I try to optimize, is a rectangle created with 4 linear Bézier polygons.
- Next I defined an displacement of the plate in z direction as a variable.
** Name: dz, expression: q1*sc1*sin(2*pi*s). Here q1(defined later) is the optimization variable and sc1 (defined as global parameter) is a scaling factor (in this case sc1=2)
- I also defined an objective function, which I tested by changing some variables and shape by hand.
- Next I added the optimization module to my model. I added my objective function as global objective. For global control variables I defined q1 with an lower (-1) and upper bound(1) and an initial value of 0.
- After that I added Deformed Geometry to my model. I selected all the solid mechanics. I added "Free deformation" to the part I want to optimize. To the boundaries of the part that I want to optimize I added "Prescribed mesh displacement" with dz as prescribed mesh displacement in z direction.
- At last I added a frequency domain study where I disabled the stationary solver and added an optimization solver.
Can someone explain me how to optimize only the top line of the rectangle and keep the bottom and sides fixed?
Thanks in advance.
Greetings Nick
PS the attachment is an overview of the geometry and the materials.
Attachments:
1 Reply Last Post 20.04.2013, 06:15 GMT-4
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Posted:
1 decade ago
I solved it. It turns out that I needed to use segregated steps, else it wouldn't solve.
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