The formula for von Mises stress for a plane stress (2d) condition with no shear stress is:
So if S1 = 1000, S2 = 0 , then Svm = 1000.
If the S2 is now increased from 0 to 500. The von Mises stress will go from 1000 to 866
I understand this is how the equation works, but can someone give me...
Very good point. The caster may be the weak point. We may need to test one to see what kind of load causes failure and what that failure looks like. Thank you.
I like this analysis, and I can see if the rear of the cart did hop up, that would be one way of dissipating the kinetic energy over a longer period of time and lowering the impact load. However, the exact geometry of this cart/machine is actually lower than shown in the sketch and I think this...
Looking at this line of thinking, and putting these equations into a spreadsheet, I've come across a common engineering dilemma regarding impacts. The stronger you make it, the stiffer it is, the higher force of the impact, and the stronger it needs to be. I've come to the conclusion that...
The machine on the cart is about 4.5 feet tall. If someone is moving it from the assembly department to the shipping department, I can see them accidently hitting something low on the ground. For example if they are going around a building column and cut it too close. They're usually pretty...
The machine is complicated, but pretty robust. It's been tipped over on it's side (about a 4 foot fall) by shippers and survived. So I think it could handle a 2g shock load pretty easily. But the bumpers is not a bad idea. As for pushing around 3,000 lbs machine, we do it by hand all day...
Yes. Agreed, the cart must be elastic as it can't stop instantly or that would take infinite force. The cart would actually not be too hard to calculate the elasticity of, but the part ON the cart (The 3000 lbs load) is actually a complicated machine that I think might be very difficult to...
I would say worst case, I imagine they could hit a step in the foundation around a building column. I would say that is easily 10x more ridged than the cart and load. So for the purpose of calculations we can assume the thing they hit is immovable, and the cart and load will stretch/flex as it...
I'm designing a cart holding a 3,000 lbs load that will be pushed around the shop floor. One structural load I am concerned about is if the operator pushes the cart into a rigid stop, how much load will that impart to the cart? I realize calculating the g-load is a very complicated problem...
A.T. Thank you! I had never heard of gravity drag. It totally makes sense now! I'll have to fully read and comprehend that article, but just reading the first paragraph really does answer my initial question. Thanks!
You're right that angle of view can make such observations difficult. However, as my 12 year old pointed out, if you watch and LISTEN to some of the youtube videos of shuttle launches, the shuttles altitude and range downfield is often announced at regular intervals. I don't recall the exact...
I meant to say they START to turn horizontally almost immediately. Of course they don't get to be totally horizontal until they're in orbit. Within a few seconds after clearing the tower, the space shuttle began it's roll maneuver. As it rolls, it is already pitching onto it's back. Within 2...