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  • 1.  Good Engineering Analogies

    Posted 12-22-2023 04:46 PM

    Recently, I was asked to explain a structural failure in layman's terms.  I was not involved with the design or investigation of the failed structure, so I could not offer a professional opinion.  I think an analogy would have been useful in this situation, but again if the analogy was not a perfect fit for this case, it could lead to more confusion.

    Do you have any go-to engineering analogies to describe a design or failure?  How was it applicable to the case you were describing?  DId the audience understand what you were describing?

    Chad Morrison P.E., F.ASCE
    Professional Engineer
    Greenville RI

  • 2.  RE: Good Engineering Analogies

    Posted 12-26-2023 11:04 AM

    In my opinion, there's 2 types of structural failures.  The first, the obvious, is when the structure fails due to an over stress and can no longer function as initially intended.  The second failure occurs when the supported structure is damaged by movements of the supporting structure.

    Samuel Vacek P.E., S.E., M.ASCE
    Vacek LLC
    Porter TX

  • 3.  RE: Good Engineering Analogies

    Posted 12-28-2023 11:26 AM

    I think one of the best analogies for structural engineering to the "layman" is comparing it to the skeletal system of your body. That's my go-to when explaining to kids what I do. Here's how I might explain my job to a kid (or adult with no engineering exposure):

    "As a structural engineer, I design all of the building components and their connections to be strong enough to stand up to all of the forces and activities it will see through the years. Just like the bones in your body need to be strong enough for you to stand, run, jump, and carry things, I design the bones of a building. I have to design the connections to withstand these forces too, just like your tendons and ligaments need to be strong enough in your body. Torn ligaments are just as bad as broken bones. Even as your feet are proportioned to spread out your body weight so that you can walk on sand or snow without punching through. I design the foundation of a building spread out the weight of the building so it doesn't sink into the ground through the years."

    I think it's a pretty good analogy. As for explaining a structural failure, I think that tends to be pretty easy to explain. There is the obvious "building fell down/over" extreme structural failure, but as a broader description: "When the strength of any building component is exceeded, resulting in permanent damage, displacement, and/or collapse of any part of the structure." That description covers failures where the building or component didn't actually fall down, but perhaps it is cracked, sagging, racked out of true, etc. All of that would be considered a structural failure, even if it's still standing.

    Gregory Latreille P.E., S.E.
    BBFM Engineers, Inc.
    Anchorage AK

  • 4.  RE: Good Engineering Analogies

    Posted 12-27-2023 12:15 PM

    Hey Chad,

    Not the same field as your specialty - but I've often heard of pipe flow likened to number of cars on a highway as a way to illustrate capacity issues.

    Christopher Seigel P.E., M.ASCE
    Civil Engineer

  • 5.  RE: Good Engineering Analogies

    Posted 01-01-2024 11:16 AM

    A long, slender object makes a great prop to demonstrate column failure by buckling and the impact of unsupported length.

    Mitch Winkler P.E.(inactive), M.ASCE
    Houston, TX