topic Re: Spaghetti Bridge Analysis in Inventor Forum

Spaghetti Bridge Analysis

Anonymous — Mon, 11 Jul 2016 07:57:27 GMT

Hi this is my first post here so hopefully I'm not doing anything weird.

I am current a first year engineering student and next semester will be completing a unit that has one of the assignments as building a bridge from spaghetti (held together by glue). I got curious because Inventor has a stress analysis feature and was wondering if before actually building this bridge i could design it in Inventor (or if you have another program that could do it better please refer) and compute the stress analysis saving a lot of material and time. All the data generated could all be put in the report.

So my question is, currently there is no material that is spaghetti, however is there a current material that would behave very similar to it? If not, is there a way to manually upload one somehow?

Any help is appreciated.

-Nick

Re: Spaghetti Bridge Analysis

smokes2998 — Mon, 11 Jul 2016 08:26:05 GMT

you could or you could have fun making a bridge. I found when i did it that if bind the spaghetti into a bunch and wrap it in in tape and glue at each end makes for the strongest structure as spaghetti is so weak as a material.

If you copy a traditional steel structure it look nice but fails really quickly as the joints and spaghetti are so weak.

Re: Spaghetti Bridge Analysis

Anonymous — Mon, 11 Jul 2016 08:57:54 GMT

Thanks for the quick reply.

Yes you're right i could, however i'm a bit pedantic so building it first and going through trail and error is a lot more headache prone for me. I do 3D print regularly and tend to test my prints before i print them for structural integrity (especially quadcopter frames) as it saves me a lot of time so i'm just going about this the same way I guess.

-Nick

Re: Spaghetti Bridge Analysis

JDMather — Mon, 11 Jul 2016 10:54:20 GMT

@Anonymous wrote:

...So my question is, currently there is no material that is spaghetti, ....

You can always add your own materials. The problem is finding the properties - and when you add the glue you have a composite.

This is what I would do -

1. Add a profile diameter for the spaghetti to the Frame Generator.

2. Add the material properties (really, any material should give you indications of weak points - even if it isn't exactly correct properties.

Model the design with the Frame Generator.

3. Use Frame Analysis.

You might start out with Autodesk ForceEffect and then move over to Inventor.

I haven't used it, but Robot Structural might be another option.

Students can get Autodesk products for free from the Autodesk Student Community.

Re: Spaghetti Bridge Analysis

smokes2998 — Mon, 11 Jul 2016 14:28:52 GMT

have a look at this pdf

http://engineering.jhu.edu/ei/wp-content/uploads/sites/29/2014/01/Spaghetti-Bridge-Construction-Hints.pdf

Re: Spaghetti Bridge Analysis

Anonymous — Tue, 12 Jul 2016 05:31:51 GMT

Wow thanks! The PDF will definitely be handy

Re: Spaghetti Bridge Analysis

Anonymous — Tue, 12 Jul 2016 05:32:18 GMT

That's probably the best way to go, will check it out thanks for the help!

Re: Spaghetti Bridge Analysis

smokes2998 — Tue, 12 Jul 2016 07:15:40 GMT

I would try and ask the lecturers what the learning outcomes of the exercise are supposed to be before going too deep into FEA.

I think if remember correctly it was to build the structure to the material being used.