topic Re: Dynamic Simulation w/ Torsion Spring in Inventor Forum

Dynamic Simulation w/ Torsion Spring

bender.terry — Tue, 27 Mar 2018 18:31:48 GMT

New to Inventor Pro, Dynamic Simulation.

Can't find a torsion spring element. Appears software only has coil springs (compression/extension). If a torsion spring can be set up, please advise where to look. If cannot be set up, then I request that Autodesk include that in later revisions. SolidWorks Motion has it. So does SimWise 4D.

Terry

Re: Dynamic Simulation w/ Torsion Spring

Xun.Zhang — Wed, 28 Mar 2018 01:30:07 GMT

Hello,

It seems a mystery to me as well, so there is no direct way to handle, however, you can constrain the legs with some workplanes to do so. Regard the design creation, please refer to -

https://knowledge.autodesk.com/support/inventor-products/learn-explore/caas/CloudHelp/cloudhelp/2016/ENU/Inventor-Help/files/GUID-5F4CC289-B17E-481D-A0E2-DFE6DD4C6C0E-htm.html

Regard to the simulation, refer to several existed posts which may inspire some new idea for you.

https://forums.autodesk.com/t5/inventor-forum/torsion-spring-fea/td-p/2424324

https://forums.autodesk.com/t5/inventor-forum/dynamic-simulation-of-cooker-lid-amp-torsion-spring-design-help/td-p/5691295

Hope it helps!

Re: Dynamic Simulation w/ Torsion Spring

jan_priban — Wed, 28 Mar 2018 09:40:47 GMT

Hello,

not sure what problem you want to solve (hinge + spring like mentioned in the related link posted here?), but torque spring can be defined as property of rotation DOF (property of rotation constrain). See please the video I recorder trying to explain. (attached as JointTorgue.mp4)

1. I placed 2 beams , constrains are axis-axis + point + point

2. Dynamic Simulation converts these constrains to Revolution joint

3. Edit properties of Revolution joint

4. Set up starting position

5. Set up (simulate) TORQUE SPRING by ELASTIC STIFFNESS

I defined also small damping to "finalize" motion. Given torque is 600 Nmm while ELASTIC STIFFNESS = 10 Nmm/deg - which means final results/angle is 60 deg (illustrated by the output graph)

Hope it explains

Regrads

Jan Priban, Autodesk Inventor team

Re: Dynamic Simulation w/ Torsion Spring

bender.terry — Wed, 28 Mar 2018 12:41:23 GMT

Jan, thanks. That helps.

It's a workaround for a real torsion spring element that has a coef of lb/deg, etc. That's what I was looking for. The mechanism I am working on has 2 torsion springs, one w/ a single coil side, the other has two coils/sides. These elements are required to properly time/size other components for a cycle time analysis. If the timing is off, the inertial reactions of free elements is off, impact forces (impulse), etc. that I need as outputs. This simulation can be done in nonlinear FEA, but convergence times are very much longer. I'm under a time crunch. Thanks again, I'll give it a try and see if I can get it to work.

Terry

Re: Dynamic Simulation w/ Torsion Spring

jan_priban — Wed, 28 Mar 2018 14:01:18 GMT

Glad it helps you. FYI:

Joint torque effort = - K . (p-p0) where K is Elastic Stifness, p is current/actual position, p0 is the Free Position