Model cannot proceed at all after switching to force load 1

[yw5aj]

Hi all,



I have a very small model that runs perfectly under displacement loads. However, when I switched to force loads, the model cannot even move one step at all. Would you please help me with this?



Thanks!

Attachment: the inp file

https://copy.com/8mpoUT8BtjfS

Figure 1. The model runs smoothly under displacement load

Figure 2. The force exceeds 1 newton under displacement load, therefore my load is not too high

 

[corus]

It's because of the contact condition you have. First impose a dummy displacement to push the parts together, then deactivate that displacement and apply your load.

 

[yw5aj]

Hi corus,

Oh man thank you sooo much! It is so obvious but I didn't think of it. I realized that the numerical singularity is coming from the contact (from the .msg file, the solver does not realize the contact at all). I tried to add a small force to push it into contact but it didn't work (still singular). This is so obvious but I did not think of it until you mentioned... Thanks a lot man!

It now worked perfectly.

-Shawn