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Design Procedure 3

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ul92

Structural
Aug 21, 2013
39
Good day Mates,

I am requested to prepare a Design Procedure. It would be deeply appreciated if someone gave me a hand. My main questions are:
- Where to refer?
- What are the main criteria’s that should be taken into account?

Many thanks in advance.
Ulvi.
 
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design of what? for what out come?


"Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning."
 
Well, the first step would be to define the problem (A). The next step would be to figure out what the end product is to be (Z). Then figure out the necessary steps to get from A to Z.
 
Sorry guys,
I need procedure for design of steel structures
 
Gents,
Let me emphasize that we normally use metric system and our job occupation is design of steel structure - lifting devices/frames, vessel modification and dozens of another areas. From the other hand designs has being done as per DNV , BS , EN and etc. standards.
 
next time you design something, write down teh steps you do.

1. observe geometry of beam to be desinged
2. figure out loads on beam
3. calculate moment and shear
4. select beam big enough to resist loads.
5. etc.


Not sure what your really looking to do
 
Many thanks for reply. But this is not what I am looking for. I want to make a paperwork that reflects how generally design work should be followed. Which toerances should be used. Or how to determine minimum design criterias. Hopefully you understand what I am meaning
 
Pardon me for being blunt, but- Are you a practicing structural engineer? This strikes me as an odd line of questioning.

Let me ask you some things-
1)What steps do you go through when you design anything?
2)What codes and standards do you use in your jurisdiction?
3)Who are your clients and what are their requirements/ design constraints?
4)Do you have standard contracts/agreements or procedures for writing them?
If you can answer any of these then you already answered most of your question. If you can't answer them then why are you setting up a paperwork which reflects how design work should be followed? The truth is, most design offices follow different procedures and every project has different requirements depending on a variety of factors. These factors should be known to anyone doing design work. You would need to supply more detailed information than you have already to get much more of a response out of anyone here beyond what has been given.

______________
MAP
 
We. Are. Not. All. Men.

Enough with the mates, guys, and gents.
 
"Which toerances should be used."

Well ladies/girls/persons of indiscriminate gender I'd always suggested the loosest possible that satisfy functional requirements.

Of course what you probably mean is something along the lines of what is the process capability of the manufacturing techniques typically used to make your kind of structures or something like that.

Posting guidelines faq731-376 (probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484
 
I think you've hit the nail on the head focuseng.
I'm wondering the same thing!
 
...and besides that, she's a damned good engineer!
 
This is a double post! This is not allowed. See my answer in Drafting Standards, GDT & Tolerance Analysis
 
Well, gent/guys/mates/dudes/ladies/girls/madams and representatives of other genders, instead of getting clarification I got stung. Why we are exacerbating the situation. Above guys asking me dozens of questions about specific job tasks. But what I actually need the name of standard or specification that I can refer in order to create our own design management procedure.

 
Ulvi, not sure if it's an ESL issue or what but your question, even with your attempted clarifications, is still not very clear or easily understood.

Perhaps if you can restate your question with a reasonable level of detail we might finally 'click'.

Posting guidelines faq731-376 (probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484
 
Ulvi:

I would say you got a reply as clear as the question.

Since we are in a structural engineering forum it is reasonable that the question relates to a "structure". A structure (in my world) can be a chair, a bridge, a building or a lot of options in between. If I design a bridge for vehicle load, that is one approach. And the floor designed for machine vibrations, another approach.

You mentioned EN standard, I assume you mean Eurocode and that is 59 standards. I have never designed anything that required all 59 but usually at least 3-6 depending on the material.

I would say "Are you a practicing Engineer" is a fair questing. It is not a matter of you getting stung, rather not understanding the question.

Based on experience, If you ask the question in a way that we can understand than you will get help. Somebody will take the time. But to describe how to design a steel structure is not something you can describe in a few sentences. You can look at the link ztungguy provided, it might help. You can also notice that it is nearly 300 pages.

Perhaps what you need is what I would call a "Design Basis Statement". Basically a document describing to the client how we propose to design the requested structure. I have written a few of those. They usually involve analysis methods, suggested codes and critera for SLS and ULS. Loads and load combinations. They are not neccesarily a lot of pages but enough to make the client able to verify that his requirements are met.

Good Luck

Thomas
 
Ulvi:
You don’t do a good job of explaining what you mean by “Design Procedure.” You say... “Hopefully you understand what I am meaning.” No we don’t. But, you have gotten some suggestions of things which might be included in some sort of a ‘design procedure.’ Do you want a ‘cookbook’ which lays out every step from the first step to the last, including when to pick up your pencil, and all you have to do is plug in the new numbers, each time? It sounds like what you really need is a real and complete engineering education, because that starts to teach you how to approach an engineering design problem, without the need for an exact procedure. Almost every engineering problem is slightly different, so one procedure likely won’t cover them all. You have to learn to think on your feet, and apply your total engineering knowledge, as that knowledge and experience fits the current problem. Your general engineering training, knowledge, experience and judgement should encompass what you need to know, how to approach the problem and what details you need to know to start solving the problem. We have kinda gotten away from this general approach to engineering in the last 15 or 20 years. We seem to need an exact cookbook, exact code section on that exact detail, or a design guide with that exact problem in it, so all we need to do is substitute the new numbers, and that’s not really engineering. Or else, we don’t seem to know what to do; we certainly aren’t teaching people to think like engineers, and apply a little of their knowledge, experience and judgement in solving everyday problems.

A design procedure might be better if it were more general, so as to cover more situations or problems in the design office. But, that also requires that you hire real thinking engineers, not just a bunch of pencil pushers and spreadsheet runners. What design codes apply, what load conditions should apply, what materials should be used. Make check lists for various types of problems and various areas and details which need special attention on those sorts of problems. It seems to me that the crux of the matter is that we need more real thinking engineers, with some experience and judgement, and less dependance on procedures and ever more complex codes. There needs to be more one on one, face to face, mentoring of inexperienced people aspiring to be real engineers. And, work done by the younger engineers and techs. must be monitored and checked by senior engineers. No fancy procedure will take the place of this oversight, more complex and convoluted codes won’t either. There are some things you just shouldn’t be pretending to do if you don’t have the proper experience and/or guidance.
 
As my Daddy always said "If the answer is in a book -they don't need YOU"
(he was an engineer too BTW)

This is the best recipe/procedure there is:
1) Define the problem
2) determine constraints
3) solve the unknowns
Since we don't have 1 & 2... I guess we are done. In my post I asked for these to be provided. Have I beaten this horse too much? Seriously.

______________
MAP
 
Dear All,

I appreciate all correspondences and would like underline that questions by focuseng are being taken into consideration almost in every single design.

Most of you know that almost every companies has quality manual in order to manage and success best quality in work process. From the other hand this manual is pointed to put physical work into paperwork due to appropriate standards. My intention is the same. I am a structural engineer. I do design for steel constructions like lifting frames/ beam/containers, offshore platforms, maintenance on vessels, tanks, workshop cranes, walkway arrangements and etc. Now, as you see my job occupation is quite large to create a specific design procedure. From this point of view I am pointing to create a general procedure that could surround my job as an engineer. Let me give you a real scenario. Let’s imagine that there is a new engineer just employed by company and has been demanded to design lifting frame. Normally first he should let daylight in client’s requirements. This is what we call Minimum Design Criteria. If client requested offshore he should refer to DNV 2.7-1 and etc. If client intended this container for multiple use he should go DNV 2.22 or etc. If client intended only for onshore purposes he should go EWS D1.1 or BS and etc. In the next stage he should designate materials. Normally I prefer to run handmade calculation then design, then frame analysis or FEA and etc. Afterward to reduce amount of overdesigned materials I double run calculation with reduced properties of material….

Hopefully you understand me better know. Numerated stages above only small part of my job process and I need to put them into relevant paperwork and convert them into internal design procedure that my company or guys after me can refer to. If any question please don't hesitate.

Regards,
Ulvi.
 
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