yes, our buddy teddy is infamous at doing that, especially on joints and members where the steel is always has stress relief, you see, anyplace and anytime there is a steel joint, whether it is on an aplliace door, pedails mounted to a bicycle sprocket or the joints and mounting points of a 110 story office building, the worst case scenario is tested...repeatedkly tested and 10 times the maximum expected force, in this case I believe that the joints would be tested for 1 million hits of striking in duty cycles by a 727jet, all this done both in minus 50 degree chambers and 3800 degree ovens.
This is fantastic!
where the steel is always has stress relief
What does this sentence mean? Are you saying the steel is stress relieved? If you are saying this then why is the steel stress relieved? (This is a rhetorical question, but I need a laugh)
Spelling: Appliance, pedals, repeatedly - you must take more care - it makes you look silly when you can't spell.
pedails mounted to a bicycle sprocket
/Pedant mode - pedals are connected to cranks which form (with the sprockets/chainrings) a chainset. They are only joined because the pedal axles have a thread (left handed on the left one) and screw into corresponding holes on the cranks. I don't know why this interface would have to be stress relief, I mean stress relieved. As for the testing of this interface, it's not required because you can calculate the required strength using mathematics and mechanics and by using material property data to choose a material that is going to be above your chosen safety factor.
the worst case scenario is tested...repeatedkly tested and 10 times the maximum expected force,
A safety factor of 10 eh. PMSL. Even in pressure vessels, which have probably the highest safety factor in modern engineering, the safety factor is between 3 and 4. If we had Bob designing stuff it would be enormously heavy. Hell we'd never have aircraft because they would be too heavy to hold off the ground with an undercarriage let alone get off the ground.
in this case I believe that the joints would be tested for 1 million hits of striking in duty cycles by a 727jet, all this done both in minus 50 degree chambers and 3800 degree ovens.
OK - I think what he is alluding to is fatigue testing (but I can't be sure). It's very hard to run a million cycles when the fatigue load you are using is 10 times the yield stress of the material you are using.
For non-engineers.
For 200°C intervals, between -50 and 3800 (I assume that's Fahrenheit, although why you need an
oven furnace capable of this for steel I have no idea) - 11 heats would be needed which equates to
I plan and manage material property testing and analyse the results in order to produce material property data for engineers to use as the main part of my job. I'd love to see the look on the face of a project manager as I told him his testing data cost would be in the hundreds of millions of pounds!
Why on earth would you want to do fatigue testing at -50°C for a product that is never going to see that operating temperature? You need a minimum of 6 test specimens for a general fatigue curve (which can then be used with a fatigue factor and safety limit) and only one of these specimens would need to run past 100,000 or a million cycles to attain a fatigue limit. I'm getting the feeling that Bob may have once spoken to people working in the aerospace industry, because in that industry it's quite routine to do tensile testing between -50 to +120°C. Infact I've done cryogenic tensile testing when I worked for a company that builds satellites; it's a PITA and costly because it takes specialised equipment and longer time.
The whole point of producing material property data is so that the engineer can perform (stress/life etc) calculations so that we don't have to go into extraordinary expense and test full scale structures. Imagine if building codes said you had to destructively test two buildings before you could build the one to be used!
humidity testing, salt spray, vibration--not sure if you have ever seen shaker tables for example
dozens--hundreds of tests
/facepalm - why on earth would you want to do these tests when they have absolutely no bearing on the structure in question and which the building codes do not in anyway specify? Madness!
Humidity testing is usually used to assess (mostly electrical) components and systems that will be exposed to such conditions. This is usually done for military aircraft because they need to operate in these climates.
Salt Spray! LOL - why on earth would you want to do salt spray testing on steel for a building that is never going to see that environment? Crazy. Salt spray tests are usually done to ensure that aircraft engines and gearboxes etc do not corrode when exposed to salt for long periods eg: coast guard helicopters/aircraft carrier jets. It's not applicable to WTC.
Vibration? Again it's not applicable. I'm actually quite well versed. because this is a subset of material property data and I once wrote an entire "environmental test plan" for the Future Lynx helicopter gearbox whist working for Westland Transmissions (now part of Westland Augusta) back in 2000. These sorts of tests are military aerospace standards and not applicable to building codes.
Bob is trying to bamboozle people with lots of names for tests and using his minute knowledge and appalling technical wording to make himself appear better informed. Unfortunately he didn't calculate that there would be someone in the room who not only steals suns, but analyst's thunder too.
Apologies for a long post but exposing the fraudulent is quite fun.
