[peteeng]

Hi Spot - What is the point of burying a steel spaceframe in a concrete casing? One of the structures will be dominate. The steel being 200Gpa will provide a preferred loadpath and the 30GPa concrete just adds mass. Or the concrete having the greater inertia (being outside) will be dominate and the steel will be doing naught. I doubt they will co-operate in a useful way. You have a philosophical issue to resolve here me thinks. Peter

[G-Spot]

Hi Spot - What is the point of burying a steel spaceframe in a concrete casing? One of the structures will be dominate. The steel being 200Gpa will provide a preferred loadpath and the 30GPa concrete just adds mass. Or the concrete having the greater inertia (being outside) will be dominate and the steel will be doing naught. I doubt they will co-operate in a useful way. You have a philosophical issue to resolve here me thinks. Peter

This is like trying to say, If you are pushing a car and a granny comes to help that because you are the dominate force the granny's effort does nothing. If 10 grannys came to help you would it still make no difference?

Anyway it was the vibration analysis that killed the space frame, too hard to dampen all those bells welded together. But I can't believe you are arguing about concrete in steel being a bad idea when most of our modern infrastructure is supported with it. The reason concrete and steel are used together is because of how thermally compatible they are.