Problems with large models and accuracy in Algor

[ttoole]

I am having some problems running a large linear static model in Algor. The model is 500,000 dof and has been running for 2 days now. Any ideas?

Also, has anyone done there own benchmarking of the 4 node plate element? I am experiencing some accuracy issues with another model when the solution is compared to ANSYS and ABAQUS both which give the same results yet Algor is off by 55%.

 

[boatengx]

Hi Sam,

I am an old Algor customer and am concerned with your comments Sam. I have some follow-up questions for you:

1. Why does the version number matter for an accuracy error of 30%? IMHO 30% is unacceptable. Does this mean that some released versions of Algor are this inaccurate? What about all the analysis done with these versions? Were the customers that bought these previous versions made aware of these issues when they were discovered and corrected? I know I was not.

2. I checked with my account manager and for us to upgrade would cost over $7000. Is it fair for us to have to pay this outrageous amount to get a version that is accurate?

Thank You
Mark S.

 

[GBor]

boatengx,

I worked in the marine industry for about 15 years and have used Algor for 10 of it. I support myself, my wife, 6 children and a business manager with it. If I do my job as an analyst, it does its job as an FEA package..."Garbage in, Garbage out".

I think if you re-read the post, you will find that Sam is trying to get the information so that he can identify the user. And I think all of his comments suggested that Algor has traditionally been better than what the OP suggests (a polite way of questioning the OPs ability as an analyst).

As for the upgrade cost...that's a business decision, but you will pay about the same amount for a variety of packages.

Garland E. Borowski, PE
Borowski Engineering & Analytical Services, Inc.

http://www.borowskiengineering.com

 

[boatengx]

Mr. Borowski,

1) I was addressing Sam, an Algor employee, and not you though I appreciate your input here as well. Nice plug for your company and its services, however. I am new to this forum and thought this was prohibited. Also, I would respectfully like to point out that the information you are providing in the first sentence is irrelevant to this thread and the point here.

2) The issue as I perceive it is that ttoole has identified a serious issue with accuracy in an older version of Algor. He has stated clearly what the conditions were that these errors occurred (warped plates). Sam has not refuted this except to say that the newer versions of Algor do not have this issue. I did not see where he said there never was such an issue.

3) Why does Sam need to identify who ttoole is? What difference does that make? If there is an issue, there is an issue. If not then say so.

4) When you say the $7000 is a business decision you are correct. It is also about what a new package costs. Decisions, decisions…

 

[GBor]

boatengx,

Forgive my intrusion, but to your comments:

1) Websites are allowed in signature blocks, I'm not soliciting anyone to go look at the site. I identified that I have been using Algor for about 10 years...much longer than most people and I trust and have trusted the accuracy enough to support my family. This wasn't a plug for my company, rather a display of my confidence in the software.

2) Unless there is another statement, Sam's comment was

Our latest benchmark tests are materially better that what you have been suggesting so please contact your ALGOR account manager to get the latest ALGOR software.

I interpreted this as, get in touch with us and we can talk you through the proper way to run our software so that you get the right answers.

3) OK.

4) What package are you buying for $7k?

Feel free not to respond. If you find my responses inappropriate, you may also "Red Flag" them and request forum management to remove them.

 

[boatengx]

Mr. Borowski,

You wrote above and I quote you...

"I would agree with you on warping and high aspect ratio elements [in Algor]. I don't like hex elements in Algor. I try to avoid using them and try to clean up my models to avoid high-aspect ratios. If it is not possible to do that with your models, but you are only doing very large linear static, you may what to try a p-element convergence code like Mechanica. If Abaqus is working well, you may also want to try Ansys. I haven't used these codes, but have seen them work."

So it would appear as if you are acknowledging these same deficiencies. I am not trying to put words in your mouth. Just restating what you said. Warping is a consequence of any model with curvature that uses 4-node plate elements. So if we just use tetra elements we are OK in Algor from what you are saying but we also have a lot of shell type models, hence our concerns.


So it would appear as if you are acknowledging these same deficientcies. I am not trying to put words in your mouth. Just restating what you said. Warping is a consequence of any model with curvature that uses 4-node plate elements. So if we just use tets we are OK in Algor from what you are saying but we also have a lot of shell type models, hence our concerns.

 

[GBor]

I'm not here to restate the entire thread. Algor disagreed with me on this statement. I suggest you contact them if you question your results and I would encourage you to do so through some method other than this forum.

I don't believe Algor to be the only tool, but when properly applied, I believe it to be an accurate one.

 

[smurgie]

boatengx,

As Garland notes, poor input can result in poor results. There is no change in accuracy in newer releases of ALGOR. You need not be concerned. We continue to add development to correct/diagnose poor input. Hence, there are newer ALGOR features to automatically correct poor input.

Also as Garland noted, I was attempting to determine who ttoole is. We do not want unhappy customers and I wanted our support staff to be able to talk directly to ttoole to address their concerns. Issues such as this are more quickly addressed by going through the normal support channels.

BTW, ALGOR ships an Accuracy Verification Manual with the software. This manual may also be downloaded from the ALGOR website (

http://www.algor.com).

This manual contains over 200 verification examples that include the corresponding theoretical solution versus ALGOR’s results. These examples are a small subset of ALGOR’s testing suite but allow our customers who have to perform their own quality assurance testing (for example, those customers in the nuclear industry) an easy method of verification.

Sam
ALGOR, Inc.

 

[boatengx]

Thanks Sam,

Just to further clarify your responses…

So the older input was poor, thus causing a 30% error? Does that mean poor quality elements introduced into the processor and the results which were generated by the packages own automatic meshing? If it was hand meshed then, I would guess it would not be poor, correct? Or do you mean poor modeling techniques (i.e., 1 element thick meshes) and if it is that does the new software not allow this to happen?

 

[smurgie]

Hi boatengx

To clarify, since their ttoole has not shared their model or results or even who they are, we do not even know if what ttoole is reporting is accurate, let alone what might have cause such results...

Also as I am sure that you are aware, poor meshes (bad aspect ratios, warping, etc.) will generate poor results. We continually develop tools to minimize the impact of poor meshes.

One possible explanation of ttoole's results would be a poor mesh. Other modeling errors could also cause the poor results. Without more data and the model, it is impossible for anybody to tell why and impossible for anybody to draw any conclusions from.

Hence, there is little reason for concern.

 

[A6FEA]

Hi Sam Murgie,

You wrote...

"BTW, ALGOR ships an Accuracy Verification Manual with the software. This manual may also be downloaded from the ALGOR website (

http://www.algor.com)"

I have been to the website listed above and couldn’t find this manual. There is a page with the table of contents, but that’s about it. I even downloaded and installed your Design Check software, then searched for accuracy verification manual and couldn’t find one. Please provide the exact link to this manual.

Thanks.

 

[smurgie]

Hi A6FEA,

The AVE Manual is in the My Account section of our web site. If you are a current ALGOR user, you should have access already. If you are not current, please contact your ALGOR Sales Representative and they will be able to grant you access to the manual.

Sam

 

[A6FEA]

Sam,

I am not an Algor customer. I am just looking around and would prefer not to interact with a sales person just yet. Is there a reason this document is protected from the general public? I would like to check it out myself to make my own assessment before proceeding to the next level of contacting a sales person for an evaluation. Why would this not be made available to anyone who visits or even registers on your site?

 

[smurgie]

A6FEA,

If you wish to receive the manual please contact me directly.

Sam

 

[A6FEA]

Just sent you an email. Thanks.

 

[patburg]

All codes should compare to NAFEMS examples no matter what version is being used.

I just come along and read this post you - In the middle you mentioned is there another code to be looked at? If this is not a dead project look at AMPS Technologies Company.

 

[ttoole]

I agree and that is why we dropped Algor. Algor may not want unhappy customers but what company would?

 

[smurgie]

Since ttoole was raising questions, I was merely asking normal technical support questions as to what, when and how the results in question were obtained. But since no data, models, results or anything else was ever delivered to me, it is clear that there is no interest in getting the truth posted on this thread. So far it has been just misrepresentations and unsupported claims.

If someone has an ALGOR model that shows that ALGOR does not pass any NAFEMS example, please send it immediately to me!


Sam
ALGOR