I should correct and say there's a lot of scatter but all of it is far below our limits. The fuses are 3/4mm pins without any grooves or reduced sections. Used in a typical knuckle joint setup with 5mm tick eye
Correct, also the fuses needed to be small, finding a material which was brittle enough with a high enough yield and low enough uts for the scenario was proving difficult to the point that the only materials we could find to implement where too strong to machine to the small diameters required...
I agree, We may have been led down a poorly laid path, but this remains the hand we are delt. If you can point us in the direction of any of the materials you mentioned, or have any thoughts how we can estimate an idealised figure, that would be helpful.
I had hoped to use mohrs failure...
Thanks for you input both.
We know that the fuses will work and have plenty of margin against the limiting load. Based on our testing +2sd on normal distribution we still have a fos of 2. Problem is is we where to get that one idealic fuse without defect, if it was very much higher we wouldn't...
Background:Long story short, we have a design that utilizes a glass ceramic (Macor(R)) type mechanical fuse that will shear prior to a defined load. This was essentially designed through trial and error and now we are in a position where we need to substantiate the design. We undertook testing...
Background:Long story short, we have a design that utilizes a glass ceramic (Macor(R)) type mechanical fuse that will shear prior to a defined load. This was essentially designed through trial and error and now we are in a position where we need to substantiate the design. We undertook testing...
The questions boil down to can I get an equation for the mechanical advantage for all angles, if not what is the maximum mechanical advantage of the system.
That's a good point MintJulep, I hadn't considered the moment provided by the guided support. I believe that the addition would make this case statically indeterminate? Or do I misunderstand
Thanks Greg, I agree that the at theta = 0 it will be P*A*Lx/Ly does this not align to my diagram? At theta 0 FS=0. I'm not sure what mistake you are referring to?
The assembly is mounted inside a unit. The point of the assembly is to push the unit laterally away from the wall. This is the entire assembly and has been shown to work in practice. Annoyingly I need to define the ratio in a formula to allow us to assess the rest of the part. There is a fixed...
Hi Greg, thanks for your input. Why do you think this? Is there a relationship between the Fp and the FS term that I have missed?
My derivation suggests that the wall force would tend to infinity which obviously cannot be true?
Thanks
O
Hi all,
I've really been struggling to come to determine a formula which calculates the mechanical advantage of a system.
The system is a vertical pneumatic piston which actuates a connecting rod, pushing a bell crank to push against a wall.
I need to determine the mechanical advantage...
