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Software for Silo-hopper 2
- Thread starter engglobal
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I have been retired a couple of years, but it was my understanding that steel silos, bins and hoppers never had a separate and distinct set of design rules.
In other words, there has not been a formal set of internationally accepted rules for silos similar to the ASME VIII/ API-650 rules for pressure vessels and tanks. There have been some BS rules accepted in the European Engineering Community (BS EN 1991-4:2006 ---Eurocode 1. Actions on structures. Silos and tanks)
Steel Silos, bins, hoppers have always been designed with the AISC rules for steel structure design.... Design methodologies also exist for concrete silos,bins, hoppers
There have been many academic papers/PHd theses by various international authors, etc on design methods.... but no one single, internationally adopted set of rules.
Because there are so many methods out there, and they vary with the country that they are used, there has been no market for a "newbie friendly" design software package ....
My opinion only
MJCronin
Sr. Process Engineer
In other words, there has not been a formal set of internationally accepted rules for silos similar to the ASME VIII/ API-650 rules for pressure vessels and tanks. There have been some BS rules accepted in the European Engineering Community (BS EN 1991-4:2006 ---Eurocode 1. Actions on structures. Silos and tanks)
Steel Silos, bins, hoppers have always been designed with the AISC rules for steel structure design.... Design methodologies also exist for concrete silos,bins, hoppers
There have been many academic papers/PHd theses by various international authors, etc on design methods.... but no one single, internationally adopted set of rules.
Because there are so many methods out there, and they vary with the country that they are used, there has been no market for a "newbie friendly" design software package ....
My opinion only
MJCronin
Sr. Process Engineer
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I use FEA for designing hopper and my local (Australian) code for determining loading. The Eurocode is probably the most comprehensive code out there. This paper discusses the differences between some of the codes:
I've also had the luxury of getting a copy of the inner workings of a major silo manufacturers calculation sheet. This particular manufacturer specs their silos to suit their client all by Excel spreadsheet. Loads US or Eurocode, design capacities to Eurocode mostly to the requirements of cold formed steel members.
I've also had the luxury of getting a copy of the inner workings of a major silo manufacturers calculation sheet. This particular manufacturer specs their silos to suit their client all by Excel spreadsheet. Loads US or Eurocode, design capacities to Eurocode mostly to the requirements of cold formed steel members.
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There are two main problems to be handled:
1) Configuration of the silo so that it flows as desired.
2) Design of the resulting silo.
There is actually an ASME short course available on #1.
On the second item, the main issue is that there is no end of variation of details, so it's hard to make one spreadsheet or software that handles it all. Skirt supports are far and away the simplest to design, but people don't like them due to access limitations. There are all kinds of leg details used on silos, and probably each could be evaluated in multiple ways. Adding in potential vibration, lack of symmetry, thermal effects, etc., complicates it all more.
Gaylord and Gaylord had a silo design book. One thing I ran across in that is one set of equations for product pressure are recommended. Then about two pages after that, "So-and-so recommends THESE factors" and using those factors, you get completely different results. The conclusion is that there is a fairly large potential variation in the actual loads produced on the silo.
I believe it was the "Structural Engineering Handbook" that had a nice section on designing the lower shell using two stiffeners and treating it as a beam. But, when I looked at that, they never said what to do about torsion in that beam- which turns out to be a major item. So be aware that some of the methods out there are not exactly perfected, either. See my separate post on Bednar's leg-design procedure, which is another similar example.
1) Configuration of the silo so that it flows as desired.
2) Design of the resulting silo.
There is actually an ASME short course available on #1.
On the second item, the main issue is that there is no end of variation of details, so it's hard to make one spreadsheet or software that handles it all. Skirt supports are far and away the simplest to design, but people don't like them due to access limitations. There are all kinds of leg details used on silos, and probably each could be evaluated in multiple ways. Adding in potential vibration, lack of symmetry, thermal effects, etc., complicates it all more.
Gaylord and Gaylord had a silo design book. One thing I ran across in that is one set of equations for product pressure are recommended. Then about two pages after that, "So-and-so recommends THESE factors" and using those factors, you get completely different results. The conclusion is that there is a fairly large potential variation in the actual loads produced on the silo.
I believe it was the "Structural Engineering Handbook" that had a nice section on designing the lower shell using two stiffeners and treating it as a beam. But, when I looked at that, they never said what to do about torsion in that beam- which turns out to be a major item. So be aware that some of the methods out there are not exactly perfected, either. See my separate post on Bednar's leg-design procedure, which is another similar example.
No. It would serve little purpose for you. It propriety made for propriety designs.engglobal said:
You haven't really elaborated on what your question and challenge is. Like I said, calculate the loads and design the walls, members and load paths to suit. The process isn't a whole lot different from most structural engineering challenges. It is just a bit more complicated calculating the loads.
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