Column Load on Angled Leg
Column Load on Angled Leg
(OP)
Hi All,
I have a question regarding a loading situation with involves a stand we use throughout our shop (think saw horse design). This stand is currently rated at 2500 lbs, however I'm having a bit of trouble verifying this rating with regards to the strength of the legs. This stand consists of a 1/4 x 2" x 4" cross tube 50" long, which is supported by 4 legs (11 Ga x 1 1/2" square). These legs form an A- frame shape at each end of the cross tube, and are "splayed" out at a 10 degree angle from horizontal (20 degrees inclusive from side to side). Now I've done plenty of column loading situations with members that are in a vertical orientation (90 degrees from horizontal), but I'm a little unsure how tackle a column which is on an angle. Is this even considered a column? My thought was to find the vector components of the applied load to determine what the true axial load is through each leg. Being that the leg is only angled 10 degrees I'm assuming that it would buckle before it would bend like a beam. Is this thinking correct? Thanks.
I have a question regarding a loading situation with involves a stand we use throughout our shop (think saw horse design). This stand is currently rated at 2500 lbs, however I'm having a bit of trouble verifying this rating with regards to the strength of the legs. This stand consists of a 1/4 x 2" x 4" cross tube 50" long, which is supported by 4 legs (11 Ga x 1 1/2" square). These legs form an A- frame shape at each end of the cross tube, and are "splayed" out at a 10 degree angle from horizontal (20 degrees inclusive from side to side). Now I've done plenty of column loading situations with members that are in a vertical orientation (90 degrees from horizontal), but I'm a little unsure how tackle a column which is on an angle. Is this even considered a column? My thought was to find the vector components of the applied load to determine what the true axial load is through each leg. Being that the leg is only angled 10 degrees I'm assuming that it would buckle before it would bend like a beam. Is this thinking correct? Thanks.





RE: Column Load on Angled Leg
Draw a free body diagram. Each leg is loaded at 10° from axial. You have a compression load that may cause buckling. You have a bending load due to the 10° angle, easily analyzed as a cantilever. You have a weld at the top. If this were my problem, I would assume zero friction on the ends of the legs on the floor, and solid support at the top.
I have no gut feeling of how it would fail. I would crunch the numbers.
--
JHG
RE: Column Load on Angled Leg
I assume you mean 10 deg from vertical?
je suis charlie
RE: Column Load on Angled Leg
je suis charlie
RE: Column Load on Angled Leg
RE: Column Load on Angled Leg
I forget who said it: "No one believes the analysis except the one who wrote it. Everyone believes the test except the one who ran it."
STF
RE: Column Load on Angled Leg
je suis charlie
RE: Column Load on Angled Leg
RE: Column Load on Angled Leg
je suis charlie
RE: Column Load on Angled Leg
RE: Column Load on Angled Leg
Typical sawhorses (at least mine) get pulled and tugged in all directions from time to time. Even sometimes while supporting heavy loads.
Some saw horses apparently are made with more thought more about the affect of longitudinally angled legs that others.
I think this one might receive some added bracing after the first vigorous use.
http://www.thissortaoldlife.com/wp-content/uploads...
Something along the lines of the 45 degree struts anchored at mid span of the main beam on these -
http://www.safethorse.com/wp-content/uploads/2011/...
This one by inspection more seriously considers loading in all directions along the horizontal plane.
http://montana-riverboats.com/Uploads/sawhorse.jpg
RE: Column Load on Angled Leg