Carrara 8.5 Physics question

bmeg

I created a chain consisting of 15 links holding the first link still and the others free in physics. I start with the chain stretched horizontally above a plane. When I animate using physics everything works correctly, loose end falls, links bounce and twist and loose end hits the floor.However at the end of the animation several of the links break and fall to the floor.

Question: How can I prevent the chain links from breaking? Is there an option to increase the material strength of the vertex objects used to create the links?

Update....Problem solved