I was able to chase down that T4 is a stable condition at room temp from one of our materials engineers. I believe what I mis-remembered is the natural aging process that is related to solution heat treating, for some reason I had it in my head that 6061 and 6013 would naturally age from T4->T6...
I have some 6013-T4 sheet that is several years old. I am assuming it has naturally aged up to ~T6. I'd like to find a curve on the aging profile of the material.. does anyone know where I can find said curve?
Ok I have solved this. What enlightened me to it, was that the stiffnesses are incredibly low, so obviously that attracts very little load. In this instance I had just assumed 1000 lb/in in both directions for the clamps when running enforced displacements. When I calculated it; it was 1400...
I am finding the tension clip is inadequate for an allowable. Looking into element averaging my enforced displacements to try and bring the loads down as well as using the tangent modulus to calculate stiffness of the clamp instead of elastic range.
I am starting to believe the tension clip...
Oh and another side question... I am finding (some) webs are being allowed to buckle at ultimate, if pristine. However since flight test is making holes of them is it enough to recover the webs original capability or does it really need to be supported such that the web won't buckle at ultimate...
This is for a flight test vehicle, we are still in production so there is no SRM. I am working spar and rib webs since I left it out on the previous post. The doublers are due to adding penetrations for flight test sensors and conduits.
The customer wants to turn one or all of the FTV into...
I'm writing up stress notes for an electrical conduit in the fuel tank, and one item of contention is that the saddle clamps have no allowables. The prime does not have test data, and as best I can tell hand waves them as having worked in the past. (the joys of systems stress!)
Analytically, I...
I am doing repair doublers for a flight test vehicle, and the rule of thumb as I understand it is that a single sided doubler should be greater than 2x the thickness of the web. As far as I understand it, this is to prevent excessive eccentricity of the built up section.
My question is how...
I am trying to calculate the natural frequency of a fuel line for a FBO/windmill condition. In the guideline document supplied by the prime, it references Blevin's Pin-Pin Multispan & pin-clamp. (Table 8-3 d & e) with the formula.
In the formula, it is asking for the eigenvalue... is there a...
