×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Optimize spring damper stiffness and damping coefficient

Optimize spring damper stiffness and damping coefficient

Optimize spring damper stiffness and damping coefficient

(OP)
Hello, I am trying to simulate an impact between a spring damper attached to a body and the ground. I have attached an image to better understand

.

As you can see, a spring damper is attached with 2 bodies, one with a bigger mass and one with null mass (used only for contact purpose). As you can see I have plotted the deformation of the spring on impact. What I want to do is to run an optimization for the stiffness and damping coefficients to find the best values so that the max deformation doesn't exceed 10 mm. My problem is I don't know exactly how to build the objective function because the deformation is variable and I only want to consider the maximum deformation. Does anyone know any solution for this problem ?

RE: Optimize spring damper stiffness and damping coefficient

Have you done the tutorial on running a DOE from View, Using Adams/Insight with Adams/View? Basically you need to create a response that latches at the maximum (abs(displacement)) seen so far, but I don't use View and I haven't done it myself. I'll be interested to see the correct solution.



Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?

RE: Optimize spring damper stiffness and damping coefficient

Why not try to Create a "Function Measure", where through "Function Builder" enter an expression of the type "abs (SPRING_1_MEA) -10", and then in the optimization window Design Evaluation Tools specify the goal to "minimize". The variables will be the values "DV_stif" and "DV_damp", for which min and max will be from 0 to 10000, for example. Write them in the coefficients of the spring. In theory, at the end you will be given a value at which the spring is compressed exactly 10mm. Do not exceed it.

Sorry for my English)

RE: Optimize spring damper stiffness and damping coefficient

Because the function builder expression will result ina time history. It is not max(abs (SPRING_1_MEA) -10), it is a curve of abs (SPRING_1_MEA) -10 vs time.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?

RE: Optimize spring damper stiffness and damping coefficient

(OP)
I have tried what you have mentioned @newbie_user. My only problem is that the optimization [abs (SPRING_1_MEA) -10] is not reaching 0 when minimizing the results, sometimes it reaches negative values. Overall the values are close to 0, something like 2.35 or -1.5, but I want to find the values for stiffness and damping that will give me a precise 10mm compression. I have noticed that the values are also influenced by the precision that you set on the optimizer. I think I am going to play a bit with those values to see if I can get a better result.

Thanks,
Cosmin

RE: Optimize spring damper stiffness and damping coefficient

newbie_user, ah, I'm not a habitual View user, I'd assumed that optimisation was being done inside Insight, I hadn't realised that it was integrated into View. neat.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Resources

Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close