MPC - indestructible link - Video 1

[polak7]

I have to create link between two bodies. When one of the bodies moves, then the link must pull the second body. I have created such model. It is presented on the video below:

https://www.youtube.com/watch?v=Aasnl-tQuSA&feature=youtu.be

Next, I fixed one body in all axis directions:

https://www.youtube.com/watch?v=4DK_Sh5mWeY&feature=youtu.be

My aim is to cause break of this link under some load. Now it is indestructible. Maybe is there such way to define the stiffness of the link? Or maybe I can solve my problem in other ways?

 

[akabarten]

Hi,

Instead using multipoint constrains (*MPC) you can use connector element.
Specific connector type should work as specific *MPC type (AXIAL with high stiffness works like *MPC, LINK).
With connector you can:
- use characteristic (like elastic-plastic with small stiffness under specific load)
- use *CONNECTOR FAILUR to define condition to remove connector
- use filed variable (*FIELD) to change connector characteristic with time

Please read Abaqus: Abaqus Analysis User's Manual, 31. Connector Elements

Regards,
Bartosz



VIM filetype plugin for Abaqus

https://github.com/gradzikb/vim-abaqus

 

[polak7]

Thanks Bartosz,
Your guidelines are very helpful. I am experimenting with very low connector stiffness now - results are nice. I tried also with *CONNECTOR FAILURE, but I do not understand clearly how limits for the forces/moments of the available components work.

Also I have one question related to application of wires. When I apply them to the vertex of the parts, then all works fine. But, when I apply them to Reference Points, then the connector does not work. Why?

In this simple model, which I presented on the video the connectors work fine, but in my main project (

http://www.eng-tips.com/viewthread.cfm?qid=390645)

incrementation errors occur when I try to connect bodies A with bodies B:

I applied different stiffnesses, but in every cases the errors have appeared.
Here is the figure, which presents the way of connector application:

and second way:

Maybe you have some hints for me?