Droptest assembly with wood material

[Hao.NguyenCongVu]

Hi everyone,

I have a cabinet (attached file) and I want to drop from a height of 400mm.
I came across the Nonlinear Transient Analysis with ball exercise but it doesn't seem to be of use in my case or I don't know how to do it.
Can anyone help me in this case.

Thank you very much

[John_Holtz · Accepted solution]

Hi @Hao.NguyenCongVu 

We would be glad to help you. What aspect of the Ball Impact Exercise are you having problems with? It is essentially identical in concept to your model.

Also, I think that some of your 278 contacts (Separation/No Sliding) are not what you want to use. Some of the components are glued together, correct? Those should use bonded contact. The other parts are probably stapled, glued, or screwed together. I would use bonded contact for those, too. In fact, I would make everything bonded contact. Replace all 278 contact with one "Solver Contact" set to Bonded type with an activation distance of 1 mm.

You may also be interested in this article for performing the "Impact Analysis" type of analysis: How an Impact Analysis works in Nastran.

Let us know what your questions are.

[Hao.NguyenCongVu]

Thank you very much for your prompt reply John,

My client also needs an additional type of analysis like this:
There is a table as the attachment files, They put 50kg force near the edge of the table. They want to know if the table has fallen?
So what kind of analysis do I need? If so can you have specific instructions for this type of analysis?

Thank you,

Hao

[Hao.NguyenCongVu]

Thank you very much for your prompt reply @John_Holtz 

My client also needs an additional type of analysis like this: There is a table as the attachment files, They put 50kg force near the edge of the table. They want to know if the table has fallen? So what kind of analysis do I need? If so can you have specific instructions for this type of analysis?

Thank you,

Hao

[John_Holtz · Accepted solution]

Hi Hao,

Why would the table fall?

• If it falls because the weight is too large and the table tips over, then do a simple hand calculation. It is a waste of time (in my opinion) to do a Nastran analysis to determine if a design tips over. (Okay, one reason to do an analysis would be if the design is weak and the load causes the model to deflect so much that it then tips over. I would not expect your table to experience large displacements that would cause it to tip.)
• If it falls because the column breaks (or something else breaks, such as the connection between the table top and the column), then do a static stress analysis. The floor is not needed; just fully fix the base to represent the contact with the floor. (You already know that it will not tip over.) If the calculated stress exceed the allowable, then you know the table will break due to the load.