3 ms·
The problem with aluminium is its resilience, not its strength. You are right that overall structural performance is governed more by geometry than by material
by 3pt14159 12y ago
The problem with aluminium is its resilience, not its strength. You are right that overall structural performance is governed more by geometry than by material strength (resisting moment is m^4 (area times quadratic distance of center of mass), although there are gotchas like lateral torsional buckling, which require bracing) the main problem with aluminium is that cyclical tensile loading leads to material fatigue with a effective material strength of 0%, while other metals can be counted on for at least 50% strength.
- IshKebab 12y agoThis is what he is referring to: https://en.wikipedia.org/wiki/Fatigue_limit https://en.wikipedia.org/wiki/Fatigue_limit
- vonmoltke 12y agoI'm not sure if you are familiar with it, but I believe that was the core problem with the aluminum-hulled Type 21 frigates of the Royal Navy. The cyclic stress imparted on the hull by wave action resulted in severe hull cracking and a relatively expensive refit to brace the hull. It also contributed to one of the frigates being sunk in the Falklands.