contact and spring elements

Hi all,
I am trying to model pounding between two 2D frames. For this reason I used contact elements but it seems like they are not 'active'. When the earthquake is represented at the structures the contact elements don't 'flash' during contact. can somebody sent me an example? my contanct or spring elements (what ever I use) should be rigid. Thanks in advance.

ps How I can upload files at forum?

Hi Tsofia,

sorry but I never used elements like that in my analysis.. Does it give you any error message in the output file?

If you want to upload stuff, you should do it on an external server: there are a lot of websites that let you upload files and then give you a link you can use to let other people dowload that file. Try mediafire or dropbox.

Cheers,

Domenico

We have students using the contact elements in both the 2D and 3D versions that appear to be having no difficulties. If you are having problems please email me your data set, together with excitation and a description of the problem (structure) and where you are having problems in the analysis. Athol Carr at a.carr@civil.canterbury.ac.nz
So far nearly 1600 aftershocks since the September 4 earthquake.

Dear All
I am having the same problem as Tsofia mentioned. The contact element does not seems to be working. It gives no results for axial force, damping force or friction force. Kindly suggest me something to fix this problem. (Btw i m trying to model impact of two buildings).
Regards
Irshad Qureshi

As indicated earlier I have students using the contact elements with no difficulties at all. As to whether they show in the pictures depends on the member length. If they are of zero length, or less than one pixel on the figure they will not be visible. How much gap have you set? maybe the contact never takes place. It might also be interesting to know the compilation date of the program that you are using. Thius is near the top of the output file.

Dear Carr

To model contact I also used a SPRING type member with IHyst = 5 or 19 and this spring can model the behavior of impact or contact. It means that the gap i provided was enough to create the impact phenomenon. Problem with the SPRING type member is that it represents only non-linear behavior with no energy dissipation. I could not find the compilation date of the program. Can i send you the file so that u can have a look? Its very simple structure that i am trying to model.

Regards
M. Irshad Qureshi

Email me the data set and excitation. Also look under the heading of the output file there should be the compilation date output. Send a copy of the first page of the output file.