Limitations of Software Packages
Limitations of Software Packages
(OP)
Hi guys,
I ran into trouble today when I attempted to model a bridge deck. Firstly, I wanted to generate a moving load for the traffic conditions that were set out in the specification, this worked, but it generated a large amount of static load cases that I thought was totally unreasonable for the design. Particularly when I need to consider different traffic loading, multiple lanes and combinations of lane loading.
Secondly, my CPU ran out of memory when attempting to invert the stiffness matrix, 2Gb.
Does anyone else run into these problems in their daily accounts?
I ran into trouble today when I attempted to model a bridge deck. Firstly, I wanted to generate a moving load for the traffic conditions that were set out in the specification, this worked, but it generated a large amount of static load cases that I thought was totally unreasonable for the design. Particularly when I need to consider different traffic loading, multiple lanes and combinations of lane loading.
Secondly, my CPU ran out of memory when attempting to invert the stiffness matrix, 2Gb.
Does anyone else run into these problems in their daily accounts?






RE: Limitations of Software Packages
As for your stiffness matrix issue, I have seen stiffness matrix in Etabs reach almost 2GB, so I could see how someone could have problems.
My question is how much RAM does your computer have? You may need to have enough to keep the entire matrix in memory, along with everything else. If you have only 1Gb or 2GB, you may simply not have enough and need to upgrade. If you have 4GB, try stopping any unneccessary applications (such as email, virus scanners, etc) to try to free up some RAM, then retry your analysis. Are you running Windows XP? If so, by default it can only take advantage of the first 3GB out of 4GB (or more). But there is a way to force it to use the RAM more efficiently, by enabling what is called the "3GB switch". Do a google search and you should find info on how to enable it. This will free up more RAM for applications to use.
RE: Limitations of Software Packages
RE: Limitations of Software Packages
RE: Limitations of Software Packages
RE: Limitations of Software Packages
If their tech support can't help him through this problem, his best bet may be to upgrade his computer, or try to simplify the model if possible.
RE: Limitations of Software Packages
I ran the job on my seniors computer that is quite faster than mine and it was able to perform the analysis no problem.
RE: Limitations of Software Packages