BrianJones

Inspired – Including Gravity

Recommended Posts

BrianJones    2

I’ve only been using Inspired for a few hours so please correct me if I’ve missed something.

I’ve noticed that when gravity is included, there are several redundant members left in the final model. I assume the analysis has left them in as they are required support there own weight. To avoid this anomaly would it be possible to include a feature whose iterations had two stages for when gravity is included? For example:

Iteration ‘1a’ wouldn’t include gravity and would only be used to remove elements whose strain is close to zero, while Iteration ‘1b’ would run normally including gravity. (I’ve attached a pdf showing my observations)

I realise this would increase the analysis run time, but assuming what I’ve said is correct, I think it would be worth the wait.

Inspired_Gravity.pdf

  • Like 2

Share this post


Link to post
Share on other sites

Hi Brian,

Do you have more background on the model? What is it? :) Gravity is best used with very large structures that have load cases with well defined (in magnitude) forces. If you have a tower, and apply a 1 N load to the top of it and run the solution, the load path will appear the same as if you added a 10,000 N load. If you add gravity to the first example, the results will be more or less incorrect because the difference in magnitudes are enormous (1N vs 1000's of N for the tower). A better approach would be to apply a load on the bottom of the structure acting downward. It isn't going to be perfect, but the overall load paths should be similar. If you approach the problem this way, you can create multiple load cases, one with just the downward acting load, and one with the downward acting load and the side load. You can then run them independently to see the contribution from each load case. I believe you will see a much more discrete answer approaching the problem in this manner.

-Andy

Share this post


Link to post
Share on other sites
views    0

Failure is the mother of success, only to make more experiments, before we know the gravity! Sorry, can not help you! God bless you!

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now