physics simulation for structural design

July 6, 2020 7:53 AM

What is some good software for physics simulations? I would like to sketch out a structure or system and simulate how it reacts to various forces. For example, a simple trampoline of a rigid surface attached to springs at the four corners, with a 100kg weight dropped from 1 meter. I have software that does something like this for rope and pulley systems, but not for systems containing levers and springs. Windows, MacOS, iPad, whatever.
posted by Nothing to Computers & Internet (9 answers total)

Response by poster: I have an iPad app called "Newtonium" which is almost what I want, but it is 2d only, and crashes whenever I make things too complicated.
posted by Nothing at 7:55 AM on July 6, 2020

You didn't use the word 'affordable' in your question, so Solidworks Simulation is a program that will do 3D structural simulations based on a model. The next step up would be a dedicated FEA program like COMSOL Multiphysics.
posted by Dmenet at 8:34 AM on July 6, 2020

For anything more serious and engineering focused, I run out of expertise. But...

Houdini? Just kidding. Well, not really, but it's worth it if you have a decade or so to learn it. I'm assuming this is for personal project and you're not like building a suspension bridge. Blender or Unity might get you where you need to go, but there's a steep learning curve there too.
posted by misterdaniel at 8:35 AM on July 6, 2020

In the US the NIST has been developing, documenting and supporting absolutely superb software to do this, but (a) it’s a really complicated problem in generality and (b) may be suffering from the current administration and (c) is usually FORTRAN.

E.g., OOF:

The OOF software provides a finite-element modeling capability to users in the field of materials science. It encapsulates advanced numerical techniques, making sophisticated computational capabilities available to materials science users who are not themselves computational experts.

[...]

SYSTEM/PLATFORM REQUIREMENTS
Intelligence, persistence.

posted by clew at 9:07 AM on July 6, 2020 [1 favorite]

The term of art is dynamic structural mechanics simulation and it's a huge field. A lot of the predictive capability comes from material models of stress/strain, how you discretize (mesh/grid) the problem, and other stuff that doesn't fit nicely into "physics". Hooke's law is fine for springs in a certain narrow regime but doesn't map to the real world well outside that regime.
posted by wnissen at 9:45 AM on July 6, 2020

Response by poster: Thanks for the answers so far. I do get that the problem space is huge, and that you quickly get into material modeling and all sorts of complexity that is far beyond what I need. I guess I hoped that there was something that would let you quickly sketch out a simple structure just to get a first approximation of how forces move through it.
posted by Nothing at 10:21 AM on July 6, 2020

I haven't used it but MS Physics (the MS is nothing to do with that MS) for SketchUp is worth looking at does multiple part moving things, magnets, chains.... SketchUp has a silly subscription model now (I think), but I've done a lot of serious work with it.
posted by unearthed at 12:30 PM on July 6, 2020

Fusion360 has FEA. Free for hobbyist/educational use.
posted by scruss at 12:33 PM on July 6, 2020 [1 favorite]

On the cheap end of the paid space, Rhino3d + Grasshopper +

Kangaroo Physics:
https://www.food4rhino.com/app/kangaroo-physics

or Flexhopper:
https://www.food4rhino.com/app/flexhopper
posted by signal at 12:40 PM on July 6, 2020 [1 favorite]