It absolutely staggers the imagination how the OP in this thread could morph into a woven steel screen over a hole in a plate or a bunch of holes in a plate; With the screen being assumed to act like a beam which developed plastic moments and hinges and having fixed end moments. This thread got ridiculouser and ridiculouser by the day and by the post. And, it only took about 23 posts to get all the way from some pretty poor first assumptions and misguided comparisons in the OP, which lead some smart people off on a wild goose chase, interesting nonetheless, and finally to a more realistic problem description. Why not start out with a description of the real problem, since you’re not sure what you are doing anyway? And, I’ll bet this would have elicited completely different responses. Correct proportions and the full picture of the problem mean a lot to an experienced engineer looking at a problem for the first time. And you would learn a lot by just paying attention to how they approach the problem and why. And, pay real close attention to what they say, they are not just twits, twittering. Look for the full meaning of what they say.
People who don’t have a good idea how to approach their problem, would be so much better off, if they did a good job of laying out and describing their problem, just the facts, but all the facts; and then letting some of the smart people here, who are willing to help and have the experience and judgement to make good sound determinations about the tack to take on solving the problem, what assumptions to make and how to approach their problem. Then, the OP’er. should read what they have to say, a couple times, for the deeper meaning, the whole meaning and thought process. Why is it so difficult to get engineers to show a sketch, with dimensions, loads, etc. and to do a good job of describing their basic problem without a bunch of their preconceived notions which just hiding the real facts of the matter?
Now consider, a woven steel screen with .16mm wires and .26mm spacing btwn. wires and wires woven at 90̊ is fairly fine mesh. The wire is probably a pretty hard, brittle and notch sensitive, with pretty high yield and tensile strengths, cold drawn, cold worked in the weaving,, etc.; probably won’t weld worth a darn either. The top edges of the 3mm holes better be pretty finely finished and shaped so that as the screen it bent over these edges into its dished shape, it is not kinked and fractured.
BA.... You would have made one hell of a good teacher (Prof.) if you hadn’t become such a good Structural Engineer and mentor instead. The patience and fortitude of a saint, the ability to boil things down to their basics, posts 17MAY13 @ 14:43 and 21MAY13 @ 2:13, nice presentation on, 20MAY13 @ 12:21, even checking the algebra, etc.
GregL.... You must be clairvoyant if you saw the wire mesh net idea coming, by the third or forth post.
Spoonful.... I think BA’s post 21MAY13 @ 23:11 suggests the proper way to analyze this problem, but you seem to be quite a difficult person to convince. And, his post 22MAY13 @ 11:02 adds some significant detail to the thought process. He’s spent (wasted?) a fair amount of time trying to help you and offer sound advice, but in almost ever cycle you have only half read what he said and meant, or misinterpreted it in some way. Paddington is also offering some good advice and a thought process/method that we often use on these kinds of problems. What is your engineering educational and experience background, please tell us. If you won’t do that, I think you should take some engineering courses, so you gain some better fundamental understanding of what the guys have been talking about. They can’t solve the problem for you. They can explain and suggest, but you have to grasp what they’re telling you from the engineering standpoint. They can’t make you an engineer in one difficult post, and Roark’s book won’t make you an engineer either, if you don’t vaguely understand where that stuff came from. You need to have a good fundamental understanding of the engineering concepts involved if you want to do what you are trying to do.
