jb1008
Petroleum
- Nov 16, 2010
- 6
Hello,
I have been designing, in brief, a rectangular box that has to take relatively high pressures and have hit a rather big snag on the way.
I am using Aluminium LM6 and have 16mm wall thickness and have calculated the deflection (Roark's deflection on a rectangular plate fixed on all sides, Machinists Handbook 28) only to find that I will get 21mm deflection. (flat face is 540x340mm)
I would like to keep the wall thickness at 16mm but add ribs to prevent any permanent deformation at 50Bar.
I am having no end of trouble trying to calculate these ribs, is there a basic rule of thumb or a 'simple' rule to follow to give me width, depth, draft, radius etc.
To make it a bit more interesting, there can be a variety of holes machined into this face. These will be combinations of a window, 100x100 and numerous Ø20 holes. These are not in a fixed position and could in any place dissect a rib.
I have attached a couple of pictures showing the lid in its worse possible form.
Thanks in advance.
James
I have been designing, in brief, a rectangular box that has to take relatively high pressures and have hit a rather big snag on the way.
I am using Aluminium LM6 and have 16mm wall thickness and have calculated the deflection (Roark's deflection on a rectangular plate fixed on all sides, Machinists Handbook 28) only to find that I will get 21mm deflection. (flat face is 540x340mm)
I would like to keep the wall thickness at 16mm but add ribs to prevent any permanent deformation at 50Bar.
I am having no end of trouble trying to calculate these ribs, is there a basic rule of thumb or a 'simple' rule to follow to give me width, depth, draft, radius etc.
To make it a bit more interesting, there can be a variety of holes machined into this face. These will be combinations of a window, 100x100 and numerous Ø20 holes. These are not in a fixed position and could in any place dissect a rib.
I have attached a couple of pictures showing the lid in its worse possible form.
Thanks in advance.
James