Screw Modeling

Mahsa Khamanehasl

Hello all,

I am trying to simulate a crash test with Radioss2022-1 using Ls Dyna .k input decks as start input!

 Could anyone please help me  how to model a bolt with preload in LS Dyna so Radioss can convert it?

I define a bolt in ls Dyna with :

(a) beam element type 9 (ELTYP=9) connected to a rigid body from both sides, and add a preload by specifying *INITLA_AXIAL_FORCE_BEAM

Or

b) solid elements for shaft, head, nut and add preload with *INITIAL_STRESS_SECTION

Unfortunately the keywords:

*SECTION_BEAM/ ELTYPE9

*INITLA_AXIAL_FORCE_BEAM

*INITLA_AXIAL_FORCE_BEAM/ *INITIAL_STRESS_SECTION

cannot be converted to Radioss format.

Is there an alternative for modeling screws?

With kind regards

Guilherme_

Hello Mahsa,

 

On this page, you can see all keywords that can be translated from Dyna to Radioss on 2022.3 version: https://help.altair.com/hwsolvers/rad/topics/solvers/rad/ls_dyna_keywords_r.htm

 

Also, there are some excellent posts here in the community about pretension on Radioss. It may be helpful for you:

3D Bolt pretensioning using HyperWorks 2022.1 for Radioss 2022

Radioss solid mesh Bolt preloading with 1D spring element

Pretension with /PRELOAD on solid bolt

Regards,

Guilherme Brandão.