Learning Forum

[bo.zhou]

Hello gentlemen，

I want to do a shock vibration with lsdyna explicit, shock condition: 18G, 6ms, half sine wave,Y direction

Question 1: I use the keyword *BOUNDARY_PRESCRIBED_MOTION_RIGID to apply the acceleration, but I found I have to release the freedom of Y on the base fix points so that the acceleration can be normal (18G). Unlike the random vibration and response spectrum analysis, I can fully fixed the base and apply the acceleration at the same time. Can you help me to explain it?

Question 2: When I was apply the acceleration, Do I need to apply a initial velocity on the oppsite direction of the acceleration? This question really confused me. I did not find a similar example from the dynaexample.

If any one have a K file model with similar condition, It will be really thanksful to share with me. Thank you!

 

 

[ErKo]

 

 

 

 

 

 

Hi

 

Ansys empl. can not share files, but perhaps other forum members can chime in and help here.

Also feel free to contact your CP (Shanghai Jiayan Technologies Co., Ltd. | Ansys Elite Channel Partner) so they can provide and send an example.

Just some brief info - Often one can perhaps just fully fix the base completely and apply acc. load (shock)
See this in the Knowledge Base  section in ACSS which you have access to (How can we apply multiple shock loads, ensuring that the vibrations are reset to zero after each shock before applying the next one in Workench LS-DYNA? ) Also ozeninc + shock + pdf doc. if you search for that.

All the best

Erko

 

 

 

 

 

 

 

[bo.zhou]

Hi Erko，

Thanks for your support.

Unfortunately I havn't find the artical your provided, could you give me a link? I couldn't even find the ACSS.

For the first question, if I fully fix the base, the result shows the acceleration on the base nodes is strange

 

Thanks

[ErKo]

 

 

Hi

Please feel free to contact your CP (Shanghai Jiayan Technologies Co., Ltd. | Ansys Elite Channel Partner) so they can provide and send an example, or look at your existing model (we can not look at any models here in the forum).

They can also help you with ACSS to log in and get started with that.

Erko