If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#71
|
|||
|
|||
Texas Parasol Plans...
clare at snyder.on.ca wrote ...
It WAS attatched. It was attatched as if it was on the plane but upside down. I'd like to take a look at the deflections for this wing from a theoretical veiwpoint. This discussion seems to have been on-going from another group. Which group? What was the final loading and deflections when the test was called off? Did the wing that was tested have the inserts as shown in the current plans or was this an earlier wing without them? Thanks Rich |
#72
|
|||
|
|||
Texas Parasol Plans...
On Tue, 28 Feb 2006 09:50:32 -0500, Curtis Scholl
wrote: Clare wrote: "No- Gary built a wing according to plans and sandbag tested it under an engineer's supervision. The engineer stopped the loading before failure because of excessive deflection IIRC." ** As you said, Clare, you are not an engineer. And you don't have current validated DATA to back you up. I have stated instances of you being incorrect in your assumptions. And in one of the instances, given you the reference for corrections of your statements. Just an update on the testing procedure and results on the TP wing tested at Kitchener Waterloo International Airport last year. The wing was instrumented with strain guages. The main spar was bending significantly between the Cabane mounting and the strut, and the strain readings were beyond the limits the engineer was comfortable with at 2Gs testing for a 600 lb plane.Failure was IMMINENT. *** Free account sponsored by SecureIX.com *** *** Encrypt your Internet usage with a free VPN account from http://www.SecureIX.com *** |
#73
|
|||
|
|||
Texas Parasol Plans...
Morgans wrote:
clare at snyder.on.ca wrote Just an update on the testing procedure and results on the TP wing tested at Kitchener Waterloo International Airport last year. The wing was instrumented with strain guages. The main spar was bending significantly between the Cabane mounting and the strut, and the strain readings were beyond the limits the engineer was comfortable with at 2Gs testing for a 600 lb plane.Failure was IMMINENT. I don't understand why the testing did not continue. Seems to me that having someone say that failure was imminent, based on strain gauges, leaves a lot of room for opinion to creep in. Somehow, I get the impression that they would not have approved of Voyager's wings either. FWIW. Richard |
#74
|
|||
|
|||
Texas Parasol Plans...
clare at snyder.on.ca wrote Just an update on the testing procedure and results on the TP wing tested at Kitchener Waterloo International Airport last year. The wing was instrumented with strain guages. The main spar was bending significantly between the Cabane mounting and the strut, and the strain readings were beyond the limits the engineer was comfortable with at 2Gs testing for a 600 lb plane.Failure was IMMINENT. I don't understand why the testing did not continue. Seems to me that having someone say that failure was imminent, based on strain gauges, leaves a lot of room for opinion to creep in. -- Jim in NC |
#75
|
|||
|
|||
Texas Parasol Plans...
On Wed, 1 Mar 2006 16:31:13 -0500, "Morgans"
wrote: clare at snyder.on.ca wrote Just an update on the testing procedure and results on the TP wing tested at Kitchener Waterloo International Airport last year. The wing was instrumented with strain guages. The main spar was bending significantly between the Cabane mounting and the strut, and the strain readings were beyond the limits the engineer was comfortable with at 2Gs testing for a 600 lb plane.Failure was IMMINENT. I don't understand why the testing did not continue. Seems to me that having someone say that failure was imminent, based on strain gauges, leaves a lot of room for opinion to creep in. They didn't want to have to shovel up the sand when the sandbags split on the floor. *** Free account sponsored by SecureIX.com *** *** Encrypt your Internet usage with a free VPN account from http://www.SecureIX.com *** |
#76
|
|||
|
|||
Texas Parasol Plans...
clare at snyder.on.ca wrote:
On Wed, 1 Mar 2006 16:31:13 -0500, "Morgans" wrote: clare at snyder.on.ca wrote Just an update on the testing procedure and results on the TP wing tested at Kitchener Waterloo International Airport last year. The wing was instrumented with strain guages. The main spar was bending significantly between the Cabane mounting and the strut, and the strain readings were beyond the limits the engineer was comfortable with at 2Gs testing for a 600 lb plane.Failure was IMMINENT. I don't understand why the testing did not continue. Seems to me that having someone say that failure was imminent, based on strain gauges, leaves a lot of room for opinion to creep in. They didn't want to have to shovel up the sand when the sandbags split on the floor. I don't have much interest on either side of this but have been reading with curiosity. This last statement was really very lame! If someone's purpose was to prove a design was deficient you would have thought they have tested to failure. I doesn't cost alot to get a couple high school kids to do the shoveling. My question, How much permanent deflection in the wings after the test? John |
#77
|
|||
|
|||
Texas Parasol Plans...
clare at snyder.on.ca wrote They didn't want to have to shovel up the sand when the sandbags split on the floor. IF that is really the reason, IMHO, that is pretty damn sorry. -- Jim in NC |
#78
|
|||
|
|||
Texas Parasol Plans...
On Wed, 1 Mar 2006 22:17:13 -0500, "Morgans"
wrote: clare at snyder.on.ca wrote They didn't want to have to shovel up the sand when the sandbags split on the floor. IF that is really the reason, IMHO, that is pretty damn sorry. Look, I was not there when the test was done, but I know the guys who were. I know the engineer who instrumented the test. The shovelling was in jest. From what I understand, they were hoping to make some modifications to the wing to make it a better wing, so did not test to destruction. After doing more analysis they decided to cut their losses and forget the project. They designed an all metal wing, which MAY eventually be used on a TP-ish plane. The strain guage information, along with the distortion under load was adequate information to tell the engineer "enough" *** Free account sponsored by SecureIX.com *** *** Encrypt your Internet usage with a free VPN account from http://www.SecureIX.com *** |
#79
|
|||
|
|||
Texas Parasol Plans...
Earlier, UltraJohn wrote:
My question, How much permanent deflection in the wings after the test? I think that that is one of the most central questions in this exchange. If there was no permanant deflection, then the material never reached its 35 ksi (some books like Machinery's Handbook say 40 ksi) yield stress, and without deflection records we'll never really know how close the test wing came to actually failing. Overall, I'm satisfied with the descriptions that a fairly valid static test was done. However, I know from watching videos of static tests and from running deflection estimates for various wings that tests even to just the design limit can result in some seriously spooky deflections. And to add to that, the spar under consideration here is very shallow, and that will also tend to give it a lot of deflection. One thing I would have expected for a test like this is a comparison between the wing under test and some sort of deflection reference like a template. Since the spar in this case has a constant depth of 2", the same template can be applied anywhere on the spar to check the deflection and deduce the stress from that. If I've run the numbers right, for a 2" tall aluminum (Young's modulus of 10 meg) element, at 35 KSI in the extreme fibers the element will have a curvature radius of about 20 feet. That may sound like a pretty shallow curve, but over four feet it results in a bend of about 9.5 degrees and a vertical deflection of about 4". But don't take my word for it, I'm _not_ an engineer... Thanks, and best regards to all Bob K. http://www.hpaircraft.com/hp-24 |
#80
|
|||
|
|||
Texas Parasol Plans...
SNIP I don't understand why the testing did not continue. Seems to me that having someone say that failure was imminent, based on strain gauges, leaves a lot of room for opinion to creep in. They didn't want to have to shovel up the sand when the sandbags split on the floor. That was a stupid childish answer. I would say Mr Scholl kicked butt with facts. |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Richard Lamb and the Texas Parasol Plans ...and Sirius Aviation | Richard Lamb | Home Built | 12 | August 9th 05 08:00 PM |
want to trade 601 plans for 701 plans | [email protected] | Home Built | 0 | January 27th 05 07:50 PM |
bush rules! | Be Kind | Military Aviation | 53 | February 14th 04 04:26 PM |
Texas Soars into Aviation History | A | Piloting | 7 | December 17th 03 02:09 AM |
good book about prisoners of war | Jim Atkins | Military Aviation | 16 | August 1st 03 10:18 AM |