Tek-Tips is the largest IT community on the Internet today!
Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!
-
Congratulations cowski on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!
structural engineering software time savings
- Thread starter Ludlow7
- Start date
rowingengineer
Structural
that depends on wether checking is included or excluded from the costing, and what level of checking is required and how many times something needs to be checked.
"A safe structure will be the one whose weakest link is never overloaded by the greatest force to which the structure is subjected” Petroski 1992
"A safe structure will be the one whose weakest link is never overloaded by the greatest force to which the structure is subjected” Petroski 1992
Ludlow7...too many variables to give you a clear answer...but
Like RE says, it depends a lot on checking (do you have a clearly defined protocol for input and documentation of your model or do you just start at one end and go to the other...if the latter, the checker has to recreate your steps..takes more time)
For small things like a portal frame or independent beam analysis or for many components and cladding analyses, hand calcs are much faster than software.
One advantage of software is the ability to do complex modeling that would otherwise only be approximated by hand calcs. Another is the graphic output and the ability to animate your model to see if it is reacting under loads in the way you anticipated.
Also keep in mind that you are obligated in many jurisdictions to validate the software analysis by hand calcs. You don't do that on every job, but you do have to feel comfortable that the software is giving you correct answers. Garbage in is garbage out though.
Like RE says, it depends a lot on checking (do you have a clearly defined protocol for input and documentation of your model or do you just start at one end and go to the other...if the latter, the checker has to recreate your steps..takes more time)
For small things like a portal frame or independent beam analysis or for many components and cladding analyses, hand calcs are much faster than software.
One advantage of software is the ability to do complex modeling that would otherwise only be approximated by hand calcs. Another is the graphic output and the ability to animate your model to see if it is reacting under loads in the way you anticipated.
Also keep in mind that you are obligated in many jurisdictions to validate the software analysis by hand calcs. You don't do that on every job, but you do have to feel comfortable that the software is giving you correct answers. Garbage in is garbage out though.
JoshPlumSE
Structural
I've always thought that the biggest time savings from software come when changes are made. Even when it's a simple project. If the architect or contractor call you up and say, "We'd like to move that support over by 4 feet. Can we do that?" If you've got good software, then you can make that change and review the effect in very quickly.... Even if you were able to do the original calc faster, you should be able to investigate these sorts of changes more quickly.
I think it depends on the problem. I save lots of time when I use my own spreadsheets for specific task that I do a lot. For example I've got a great wind calculation spreadsheet that takes me through all those tedious calculations. I can do in a few minutes what would take hours by hand if I had to go through all those tables over and over again.
For foundations enercalc has been good for me. For retaining walls again Retaining Wall Pro has been a life saver. Retaining walls by hand are a nightmare. I use Desconwin for steel connections and again it saves me tons of time. I think they save lots of time because every project is different. If I designed beam connections everyday using the books would be the quickest. But when I only do a set of beam connections every other month or so then the software really helps. Plus they product connection details via DXF files. Another area where software can help is when designing a simple steel column with an eccentric load on top. By hand it takes a while but on software very fast.
On the other hand I can still do simple beam designs myself very quickly without any software or the book keeping it requires.
I agree with an earlier statement. CAD drafting definately save you time with the changes and it cleaner over the long term.
A warning on Enercalc. I used their new program a few years ago and found three mistakes after using it 4 times. So I dropped it and use their older software when it still makes sense code wise. This was a few years ago so it might be better now.
The spreadsheet programs save me time doing the small repetitive calcs. More powerful programs like RISA 3D save time when the problem is large and complex. So you've got to have a good bit of modeling to do before it will save you time. But the more you use them the lower that threshold is.
I've only had to design one mat foundation but I know dimensional solutions has a program I tried once and it looked pretty good. Again because that is a problem you aren't going to do everyday it will save you time.
I think tracing the loads by hand through the structure saves time versus modeling. And I think doing the actual design routines is faster with the software. Plus you can make changes instaneously.
John Southard, M.S., P.E.
For foundations enercalc has been good for me. For retaining walls again Retaining Wall Pro has been a life saver. Retaining walls by hand are a nightmare. I use Desconwin for steel connections and again it saves me tons of time. I think they save lots of time because every project is different. If I designed beam connections everyday using the books would be the quickest. But when I only do a set of beam connections every other month or so then the software really helps. Plus they product connection details via DXF files. Another area where software can help is when designing a simple steel column with an eccentric load on top. By hand it takes a while but on software very fast.
On the other hand I can still do simple beam designs myself very quickly without any software or the book keeping it requires.
I agree with an earlier statement. CAD drafting definately save you time with the changes and it cleaner over the long term.
A warning on Enercalc. I used their new program a few years ago and found three mistakes after using it 4 times. So I dropped it and use their older software when it still makes sense code wise. This was a few years ago so it might be better now.
The spreadsheet programs save me time doing the small repetitive calcs. More powerful programs like RISA 3D save time when the problem is large and complex. So you've got to have a good bit of modeling to do before it will save you time. But the more you use them the lower that threshold is.
I've only had to design one mat foundation but I know dimensional solutions has a program I tried once and it looked pretty good. Again because that is a problem you aren't going to do everyday it will save you time.
I think tracing the loads by hand through the structure saves time versus modeling. And I think doing the actual design routines is faster with the software. Plus you can make changes instaneously.
John Southard, M.S., P.E.
rowingengineer
Structural
Josh,
That depends on if you believe a recheck of all assumptions is required and then a full check completed again, alternatively you may believe that because you checked the first time and the computer was correct, then a second check isn't require. Engineers make these judgements everyday.
John, how many hours did you spend checking you spreadsheets, hours and hours I would hope.
Most of my time is spent correcting mistakes, generally these mistakes come from poor understanding of the software they are using. Sometimes these are in house and sometimes these are in the field, generally the field mistakes are from quick changes in a program with poor checking.
"A safe structure will be the one whose weakest link is never overloaded by the greatest force to which the structure is subjected” Petroski 1992
That depends on if you believe a recheck of all assumptions is required and then a full check completed again, alternatively you may believe that because you checked the first time and the computer was correct, then a second check isn't require. Engineers make these judgements everyday.
John, how many hours did you spend checking you spreadsheets, hours and hours I would hope.
Most of my time is spent correcting mistakes, generally these mistakes come from poor understanding of the software they are using. Sometimes these are in house and sometimes these are in the field, generally the field mistakes are from quick changes in a program with poor checking.
"A safe structure will be the one whose weakest link is never overloaded by the greatest force to which the structure is subjected” Petroski 1992
Amen. I would've said "When the architect..." instead of "If the architect..." though, LOL.
What you've typed is even true with the simplest design such as that of a simply supported beam. When a load moves, load increases or decreases, the span gets shorter or longer, etc., the new design with a program takes a small fraction of the time required for the original design. With a manual calc, such changes often require complete redesign that took almost as long as the first try.
- Status
Similar threads
- Question
- Locked
- Question