2x2x.250x120"=55lbs x 2=110lbs 2x2x.067x16"=1.68lb per ft so if i space these every 10" on a 120" run itll take 12 total at total of 20.16lbs add the 110lbs plus the 20.16=130.16lbs total total weight of a 10ft ramp. this look right, itll support 2500lbs with a deflection of under 1/2" ?
Reply:I think you're going about this all wrong IMHO. Anyway a quick check with beamboy shows that you're going to get 1.65" deflection and 41.1ksi stress on this design. Not even close to being enough. Changing to 3" channel goes down to 0.904" deflection and 33.9ksi getting close but just not enough for a 10' span. This is my standard for 5-6' ramps for utility trailers. Looks like you'll need 4" channel with .39" deflection and 19.5ksi for 10' ramps. Still a little high on the stress IMHO but possible. Trussing it would increase strength without adding a lot of weight. The good thing is that it doesn't weigh anymore than your 2x2x1/4 tube. In fact it's slightly lighter. For cross members you need to keep the weight down as well. Try angle iron laid down like a "V" instead. Depending on width of ramp likely 2"x3/16" leg would be thick enough. If you must span 10 feet without support you need a lot more engineering. Nobody will be willing to give advise on that on a forum like this. At least nobody I would trust.Millermatic 252XMT 304'sDynasty 280DXHypertherm PowerMax 1250Miller Trailblazer 302 EFIOptima PulserXR feeder and XR Edge gun and more athttp://members.dslextreme.com/users/waynecook/index.htm
发表于 2021-8-31 23:03:14