• SaveTheTuaHawk@lemmy.ca
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    3 days ago

    Your engineering knowledge needs some work. Most vehicles today have aluminum sub frames and suspension links. Aluminum only fatigues if stresses are beyond the design threshold. Whick is exactly why planes fly millions of miles, and are really only retired because of fuel efficiency.

    • TranscendentalEmpire@lemmy.today
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      3 days ago

      Most vehicles today have aluminum sub frames

      A unibody frame is a bit different than a subframe. You can’t reinforce stress points with steel in a unibody frame like you can with a subframe . And no, most (63%) vehicles still use steel for subframes.

      Aluminum only fatigues if stresses are beyond the design threshold.

      What are you talking about? Cast aluminum lacks any distinct fatigue limit, so any cycle load causes microscopic damage at stress points.

      planes fly millions of miles, and are really only retired because of fuel efficiency.

      Again… Where are you pulling this from? Even aircraft grade Aluminum is about 50% more susceptible to metal fatigue than steel. All aircraft have to have routine inspections specifically for metal fatigue and part of regular maintenance is to replace what they can.

      engineering knowledge needs some work

      Right back at ya… I’m guessing you don’t work with metals in your job? Anyone working in practical engineering or metal fabrication knows aluminum has a big problem with cyclical loads.