Pounding element properties

[samearthquake]

Hi everyone

I'm working on pounding problem. I used a zerolength element with ElasticPPGap material to represent the point of impact in two buildings that pound together, but I don know what values should I use for $E and $Fy in ElasticPPGap material?

I would be so grateful if someone could guide me.

Thanks

[samearthquake]

Is there anyone who can help me?

Thanks