Problem with stress and deformation orthosis project

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  • Last Post 2 weeks ago
Francisco Guerra posted this 2 weeks ago

Hello to everyone,

I kindly request your help. I'm working in a project related to the fabrication of a hand orthosis for rehabilitation to be printed in 3D. I did the entire model in Solidworks which is composed by 1 central component that cover the metacarpals - wrist and 5 components (fingers) that are composed by 3 phalanges and 2 pins (except the thumb that have less parts) plus and extra pin to connect these fingers to the central component. Phalangeal material is ABS and pins are SS304.

I'm using workbench 18.2, static structural, to get the equivalent (v-m) stresses and the total deformation of the 3 phalangeal and pins of the index finger due to a force of 22N (this force represent a flexor tendon along the entire figer). When I'm using all bonded contacts and the boundary conditions of gravity, force and fixed support, the program gave me the v-m stresses and the deformation without problem... but then with some contacts changed to frictional (0,2 and adjust to touch ) the program gave me 2 alerts: that the solve was unable to converge on a solution for the nonlinear problem and also: the unconverged solution is output for analysis debug purpose.

I want to know if you can help me about what I'm doing wrong in ANSYS? maybe the problem it's because the contacts that I set to frictional aren't? maybe the model can't be tested under those conditions? maybe I need to add some joints into model?

I'm sorry for the extensive text but this is my first time in the forum and I tried to include all the information. You will find the project files (.wpbz) in the following wetransfer link: https://we.tl/t-li5cUaxPDZ

Thank you¡¡¡

SandeepMedikonda posted this 2 weeks ago

Hi Francisco, 

  There are several reasons why this could happen, it is hard to pinpoint exactly from your description (images usually help). Note that this is a very common problem and there are several discussions on the community that should help you debug. Please see here:

Discussion 1

Discussion 2

Discussion 3

Discussion 4

Regards,
Sandeep
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