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Error # 2148

Altair Forum User

Hello,

I am new to Optistruct and having a repeating error for my 2D linear static topology optimization. When I try to run it w/Optistruct, the error that I get is:

*** ERROR # 2148 ***

Invalid design problem.

All the sensitivities of response 2 (objective) are zero.

My response(2) is compliance, and I have a simple maximum constraint on volume fraction as my other response. Any ideas about a possible reason for this error?

Thanks,

rbay

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Altair Forum User

Hi rbay,

Please check whether a proper load step is defined or not in your model.

Altair Forum User

Yes, I have defined a proper loadstep as linear elastic, and recreated it, but still receive the same error.

Altair Forum User

Hi Rbay,

can you share the model please?

Altair Forum User

I actually was able to resolve the problem yesterday. I did not specify thickness T in the property card for my PSHELL property to 1. After I did that it worked.

Thanks anyway!

Altair Forum User

Okay, thanks for the update /emoticons/default_smile.png' alt=':)' srcset='/emoticons/smile@2x.png 2x' width='20' height='20'>

Altair Forum User

I want to implement Topography optimization in Optistruct. I am having similar challenge; I have not been able to resolve it. The error message:

Messages for the job:

*** ERROR # 2148 ***
Invalid design problem.
All the sensitivities of response 2 (objective) are zero.

My file is attached.

Objective: Minimize compliance

Please, help me figure out what I am doing wrong. Thank you.

Unable to find an attachment - read this blog

Altair Forum User

Hi Samuel,

The applied load is on a temp node. Please delete all temp nodes and create load again.

Altair Forum User

Okay. Please, how can I delete the temp nodes? Thank you.

Altair Forum User

Geom>Temp nodes>clear all, this will remove all the temp nodes in your model.

Altair Forum User

Thank you, ank.

Please, how can I achieve the following?

I want to set up an optimization in hypermesh.

I want to reduce the size of my model (shape optimization). This will increase the compliance of the model. So I want to use topography optimization to apply beads to the optimized shape such that the original compliance of the model before the shape optimization is preserved (or even become better).

How can I combine topography and shape optimization in hypermesh?

Thank you.

Altair Forum User

For more information, you can download a free copy of optimization book for HyperWorks: http://www.altairuniversity.com/free-ebooks-2/

<?xml version="1.0" encoding="UTF-8"?>

Altair Forum User

Hi @samuel88

Please refer to the Ebook which @ank referred.

Can you tell us in detail about the requirement?

What do you mean by reducing the size? Do you mean that you want to reduce the size of the part?

Altair Forum User

Hi @Prakash Pagadala

Please, find my attached model below.

This is what I want to achieve:

Reduce the area of the cantilever to 60% of the initial area by using shape optimization

Reduce the compliance of the cantilever to 55% of the initial compliance by using topography optimization

I want to use the combination of shape optimization and topography optimization. I want to optimize the shape of the cantilever with shape optimization. By reducing the surface area of the cantilever to 60% of the initial area, that might cause an increase in compliance. But I want my final compliance to be 55% of the initial compliance. In order to achieve that, I want to add beads by implementing a topography optimization. I want both shape optimization and topography optimization to run simultaneously. Please, help me. Thank you.

Unable to find an attachment - read this blog

Altair Forum User

Well,

I feel you can run a shape optimization and try topography later.

Altair Forum User

That is what I am doing now. But I am getting this error message:

*** ERROR # 1744 ***
Missing BMESH ID 1 referenced by DSHAPE card.

How can I resolve it?

Altair Forum User

Hi,

Please check the following:

1) Does Free shape Dvs have nodes defined in it?

2) Do you have contacts in your model? If yes convert contact elements to BMFACE elements instead of CQUAD using 2D element type update.

Faisal

Hi,

Please check the following:

1) Does Free shape Dvs have nodes defined in it?

2) Do you have contacts in your model? If yes convert contact elements to BMFACE elements instead of CQUAD using 2D element type update.

Hi,

As i am getting this error could you please have a look on my .out file

*** ERROR # 2148 ***
Invalid design problem.
All the sensitivities of response 4 (objective) are zero.

Unable to find an attachment - read this blog

Adriano_Koga

please check if your free-size area (design space) is affecting your responses, and if your loadcases are correct.

Usually this is related to the design space not affecting at all the responses/objective.

Sometimes it is just a loadcase that is not properly assigned or configured.

Faisal

please check if your free-size area (design space) is affecting your responses, and if your loadcases are correct.

Usually this is related to the design space not affecting at all the responses/objective.

Sometimes it is just a loadcase that is not properly assigned or configured.

Hello Sir,

As i have cross checked my model the load case are alright. Because with the same model i am able to run the anlysis by keeping other objective like minmax stress. But at the same time when i kept Minmax composite failure and i am getting this error.

Antonio Gallo

Hi, I am new to Altair SWs. I am trying to make a lattice optimization of a model, but when I try to run the file "*_lattice.fem" which comes out of the Phase I of the lattice optimization, I always get this error message.

*** ERROR # 2148 ***
Invalid design problem.
All the sensitivities of response 1 (objective) are zero.

The model is made of three parts, two of which are made of aluminum and are connected to the third one, which is made of composite. For each subcase I have a force applied to a node and a maximum displacement constraint on the node itself. The analysis is inertia relief (INREL,-2) type.

The response is the mass of the aluminum parts but it seems that the size optimization of Phase II of the lattice optimization process doesn't affect the total mass of the aluminum part. Any ideas about a possible reason for this error?

The .hm file is attached below, since the .fem file itself is too big to be uploaded.

Thanks,

Antonio.

run1_lattice.hm