Mechanical engineer from the Netherlands here. I had to convert everything to metric as we don't use freedom units, but given your information it can be treated as a cantilever beam of 6.7 meters. With a density of 7850 kg/m3 only supporting its own weight. 1045 steel has a yield stress of at least 300 MPa. Doing the math, the highest stress will be right at the point of the sling and will have a static load stress of 182 MPa. So, short answer is you will be fine. As @chillbro1010 says, as long as you do it smoothly you will be good. Jerking movements can amplify the stress a lot which could lead to bending. Also don't hang it like that for too long. Especially if it is warm out. Creep stresses can cause deformation, even if you are well below the yield stress. That is why shafts on big power plants are always kept rotating slowly during down time, to prevent sagging of the shaft due to creep stresses.
@OgiveBC
19 күн бұрын
Welcome from Canada! My grandparents on one side of the family came from the south part of your country. Thanks for the great reply, sorry about the imperial units. I’ll do an answer video soon. Almost all bar stock here is supplied in 20 to 24 foot lengths. Would an increase in diameter and not length result in a same better or worse condition? Also we have several forklifts and the one shown in the video has the shortest forks, the larger has forks at least twice the length, so would lessen the bending moment a fair amount. Not how we usually /ever handle material however. Thanks again for the comment.
@impactodelsurenterprise2440
18 күн бұрын
Wow learnt new things today
@stefanfoot3047
18 күн бұрын
@@OgiveBC Oh very nice! I'm actually originally from South Africa, but have been living near Amsterdam for 2 years. So I went ahead and simplified it for you. The following calculation is only really applicable for 1045 steel as other steels might have different densities and yield characteristics. But in a pinch should be accurate enough for most kinds of steel. Use the equation: Stress % = 46 * free length^2 / Diameter With it you will be able to calculate the stress in round stock. The free length is the length of the unsupported section, in feet and diameter is in inches for your convenience. This will give you a percentage of yield stress. So if that stress % is above 100, you might get bending. Below 100% you will be good. So to answer your question. The longer the free length, the worse, the thicker it is, the better.
@OgiveBC
14 күн бұрын
I’m very impressed with the formula you have created. To me it is just magic that you could reduce a complex question to a simple equation. Thank you. When I make a final video where I put that bar on the rollers to prove it’s straight, may I show your comment in that video and give you credit for it? I’m sure some people would be amazed to see it.
@chillbro1010
19 күн бұрын
Assuming a completely static system using the worst case numbers I'm getting about ~8,000lb of force at the fulcrum. In my very unprofessional opinion as long as you lift smoothly and don't go bouncing around and putting accelerations on it you shouldn't hit the yield point while rigging with a 2 inch strap. However real life isn't so cut and dry, I would put it down on pallets while not actively moving it. You're more likely to damage the strap and drop that bar 4 feet (which would probably put a permanent bend in it). Check your straps regularly and before every lift and especially when doing stuff that looks a little iffy like this.
@OgiveBC
19 күн бұрын
Thanks for the comment, we usually move bars by picking them up from the middle with a forklift and the bar sideways, as I’m sure most people do. I’ll do an answer video soon. Good point about the sling, it would see a lot of strain. As to the bouncing while driving…….could get interesting
@Cheezeball99999
19 күн бұрын
Well given that you did this, I would assume that it's fine. I used no math, of course.
@OgiveBC
19 күн бұрын
This is the first time I have tried with a full length bar. I had a hunch but no mathematical proof. Will do an answer video soon. Thanks for commenting.
Пікірлер: 9