jbn@wdl1.UUCP (09/18/85)
Some years ago, at Case Institute of Technology, in Cleveland, mechanical engineering students were required to take a course in structural engineering in which the grade was based entirely on one project. The project required designing a flat metal link. The link was to be made of a specified grade of aluminum, and had to carry a specified load. The link couldn't be straight; there were obstacles between the pins that the link had to go around; the obstacles changed from year to year. Each student turned in a drawing of their link. A machinist actually machined the link out of sheet aluminum; the student checked the link against the drawing, and when satisfied, presented the link for grading. The link was placed in a hydraulic testing machine and the specified load applied; if the link broke, the student failed the course. Passing grades were then computed based on weight, with lighter weight links receiving higher grades. This may seem harsh. But this is what engineering is all about. John Nagle
cdshaw@watmum.UUCP (Chris Shaw) (09/23/85)
In article <702@wdl1.UUCP> jbn@wdl1.UUCP writes: >The project required designing a flat metal link. The link was to be made >of a specified grade of aluminum, and had to carry a specified load. > >Each student turned in a drawing of their link. A machinist actually >machined the link out of sheet aluminum; the student checked the link >against the drawing, and when satisfied, presented the link for grading. >The link was placed in a hydraulic testing machine and the specified load >applied; if the link broke, the student failed the course. Passing grades >were then computed based on weight, with lighter weight links receiving higher >grades. > >This may seem harsh. But this is what engineering is all about. > > John Nagle Sure. I'd hire a engineer who designed by theory alone... Hell, what is test equipment for but to see if eng. students can design things that hold up to specified stresses. What if the stress specifications are wrong ? What if the aluminum has bubbles in it ? What if any number of things? THIS is what engineering is all about !!! Not just whether you know theory or not, but whether you know enough about your field to design something to work in all (or all plausible) situations. Not that I'm trying to tell John his business, but this example course of his sounds kinda silly. Chris Shaw watmath!watmum!cdshaw or cdshaw@watmath University of Waterloo In doubt? Eat hot high-speed death -- the experts' choice in gastric vileness !
jbn@wdl1.UUCP (09/25/85)
When you design large structures, such as bridges and buildings, the design is normally validated by structural analysis, with generous safety margins to allow for flaws in the materials and other problems. But you don't normally build a scale model of the entire building and subject it to static testing; the theory is well-enough developed that static behavior is predictable. So structural engineers must learn how to design, on paper, buildings that will definitely stand up. John Nagle
rcd@opus.UUCP (Dick Dunn) (09/25/85)
[on an ME course at Case] > ...project required designing a flat metal link. The link was to be made > of a specified grade of aluminum, and had to carry a specified load. > ... > Each student turned in a drawing of their link. A machinist actually > machined the link out of sheet aluminum; the student checked the link > against the drawing, and when satisfied, presented the link for grading. > The link was placed in a hydraulic testing machine and the specified load > applied; if the link broke, the student failed the course... > ... > This may seem harsh. But this is what engineering is all about. But it's not what teaching is all about. -- Dick Dunn {hao,ucbvax,allegra}!nbires!rcd (303)444-5710 x3086 ...If you plant ice, you're gonna harvest wind.
eugene@ames.UUCP (Eugene Miya) (09/26/85)
> > When you design large structures, such as bridges and buildings, the > design is normally validated by structural analysis, with generous safety > margins to allow for flaws in the materials and other problems. But you > don't normally build a scale model of the entire building and subject it > to static testing; the theory is well-enough developed that static behavior > is predictable. So structural engineers must learn how to design, on paper, > buildings that will definitely stand up. > > John Nagle Actually, I worry alot about this [note this is not directly CS]. Two DOD cases in point: the Sargent York and M2 Bradley fighting vehicle. Neither of which has undergone "full-testing." York is well documented. Bradley -- FMC refuses to hit one with a shell fully loaded. Have we lost confidence in our design and engineering methods? My subtle worry is about using computers to economize (CAD) on a product which otherwise might be over-engineered into "safe" design. Such designs might be alright under normal conditions, but in the twilight zone of the boundary condition: perhaps, the building falls, the plane drops out of the sky, the bridge ..... This has happened in many cases, and I am glad the fa.risks board has started. I don't think software is any different except perhaps we might be a bit more removed from the consequences [See discussion on the ARPA soft-eng board for more]. From the Rock of Ages Home for Retired Hackers: --eugene miya NASA Ames Research Center {hplabs,ihnp4,dual,hao,decwrl,allegra}!ames!aurora!eugene emiya@ames-vmsb