59 Replies Latest reply on May 10, 2010 11:33 AM by Bill McEachern

    Simulation vs. NEIWorks

      Does anyone have opinions on upgrading to Solidworks Premium vs. purchasing the NEIWorks Add-in for plain old static loading FEA applications?  Xpress isn't cutting it and I'm on the fence as to which upgrade to make.

       

      Thanks for your input!

        • Re: Simulation vs. NEIWorks
          Robert Stupplebeen
          Get free trials and benchmark.
          • Re: Simulation vs. NEIWorks
            Alessandro Frattini

            SIMULATION has :
            - better integration into SolidWorks

            - minor bugs
            - mesher more "robust"

            - Simulation constrains / contacts more "stable" and in the 99% more efficient

            - better POSTPROCESSING

             

            NEiWorks has :
            - solutor more advanced into composite material
            - compatibility with MSC - NX Nastran reports (need in aeronautic certification)
            - NEiWorks cost a little less

            • Re: Simulation vs. NEIWorks
              Joe Galliera

              Watch this video from NEI: http://www.nenastran.com/videos/NEiFusion_SpringModel.html

               

              We have attempted to reproduce this simulation in SolidWorks Simulation with the same model of spring.  Below are the comparative statistics after running the same simulation in SolidWorks Simulation: 


                            Nei Fusion         SolidWorks


              DOF           348 391            363 279

              Mesh          30 sec.            38 sec.

              Calculation    3 min.            17 sec.

              We calculated a displacement of 0.4868 inches, which if you calculate the spring rate as he does in the video comparing that to theoretical one, we get a much closer result than Nastran.  When calculating displacement, this is the unknown parameter so it should be the most accurate because it is the basis for strain and stress which are calculated from this.

              Spring Rate (note: the original video actually uses this many digits, obviously forgetting about significant digits)

              Theory: 2.060517191 lbf/in
              NEiFusion: 1.996000016 lbf/in, 3.1% error from theory
              SW Simulation: 2.054231717 lbf/in, 0.3% error from theory

                • Re: Simulation vs. NEIWorks
                  Bill McEachern
                  Nicely done.
                  • Re: Simulation vs. NEIWorks
                    Alessandro Frattini

                    Hi Joe,

                    can you post your SW test spring file?

                    I'm trying to do what you have done with SW, but SW stop before to complete the analysis.

                      • Re: Simulation vs. NEIWorks
                        Joe Galliera
                        Use a mesh size of 0.011 in to get the number of DOFs, and assume small displacements.  Completed with SW Sim 2009 SP4.1.
                          • Re: Simulation vs. NEIWorks
                            Alessandro Frattini

                            Hi Joe,

                            I see that the diameter of your spring is different from that of the video, as well as the elastic modulus.
                            The test is not reliable if you do not use the same values.
                            If I set Large Displacements, where I find the option to set the analysis with Small Displacements ?

                              • Re: Simulation vs. NEIWorks
                                Joe Galliera

                                Everything is the same.  The video author creates a 0.5 in circular sketch for defining the helix, height 1" and 8 revolutions starting at 180°, and the spring wire diameter is defined as 0.035 in, the same as for the model I attached.  The pertinent material properties are the same: 29e6 for modulus of elasticity and 0.32 for Poisson's ratio, same as in the study attached.  At the end of the video, the author makes a chnage to the wire diameter making it 0.05", which in my  attached model there is a "Thick" configuration but no Simulation study has been created for this config; one would simply have to duplicate the original study, choose to copy it to the new config and then run.

                                 

                                Small displacements is the assumption for a linear static analysis, so there is no required setting.  The same was done essentially in the video for NEiFusion.  SW Simulation warns you at the end of the calculation that it has detected large deformation, but by selecting "No" in that dialog box it will give you results based on the small displacement assumption.  NEiFusion does not provide any warning, which is somewhat troubling especially to a novice user who might takes these results as is.  Though I am not faulting the author of the video, he is simply following the same assumption that the theoretical solution takes.

                                  • Re: Simulation vs. NEIWorks
                                    Alessandro Frattini

                                    Sorry Joe,

                                    I watched the vido better and I saw that he types 0.035 although the dimension show 0.04.
                                    I looked at the material and actually is the same but with different exponential.
                                    I apologize for my superficiality observing the video.
                                    I'm glad however that you have demonstrated the Simulation superiority and all these data will also be listed on the SolidWorks Italian forum.

                            • Re: Simulation vs. NEIWorks
                              David Anderson

                              as a comparison, i ran the model in Workbench ANSYS 12.0 with both a course and a fine mesh

                               

                              for run 1, ansys defaulted to swept bricks which is my preference over tets (not sure why NEI would use tets when you can sweep it with high order bricks. must be a default element?)

                               

                              run 1

                              brick elements: 9180

                              nodes: 49611

                              large deflection "on"

                              mesh time 10 sec

                              total solve time:60 sec

                               

                              results

                              deflection: .48446 in  (large deflection off=.48201)

                              k= 1lbf/.48446in = 2.0644 within .1% of theory.

                               

                              run 2

                              tet elements: 79917

                              nodes: 134274

                              large deflection "on"

                              mesh time 10 sec

                              total solve time:223 sec

                               

                              results

                              deflection: .48386 in

                              k= 1lbf/.48386 in = 2.0678 within .3% of theory

                               

                              in my experience, it is best to use bricks when possible.

                               

                              the results from NEI are horribly far from theory and from ANSYS and SW. i am not sure that the theory is exactly correct for large deflections such as this spring. regardless, one can always solve a linear static problem using a nonlinear solver and get the same result, it will just take longer to solve.

                               

                              the large discrepancy for the NEI solution bugged me so i re-ran the model with gravity on to see if i could get the same number as NEI. got .48529 which is still way off. very wierd.

                            • Re: Simulation vs. NEIWorks
                              David Anderson

                              Jeff,

                               

                              I have selected a number of FEA packages for two different companies. i came out of the aerospace industry and into a startup in 2000 so when choosing an FEA package, i naturally looked at NASTRAN, SDRC I-DEAS and ANSYS. we ran many test cases and not always, but often COSMOS would yield different results than NASTRAN and ANSYS. I had also been a COSMOS user since 1993 but ultimately we ended up with both ANSYS and NASTRAN.

                               

                              Then for my own company, I opted for ANSYS and have been very pleased as the Workbench interface is really great and my parts do not end up being saddled w/FEA data. My preference has always been to decouple the FEA and CAD software yet have seamless model transfer.

                               

                              Before you buy, take a look at ANSYS Workbench as well. Make sure that current needs and future needs can be handled by the package you buy or adding modules. i can tell you this, its a big nut to spend and once you do it is damn hard to go back to another software as you will have lots of time and and money invested. Don't forget to budget fot the 20% yearly maintenance. For me, i pay more in FEA maintenance each year than the cost of SW professional.

                               

                              Good luck,

                               

                              Dave

                                • Re: Simulation vs. NEIWorks
                                  Robert Stupplebeen
                                  If the discussion is opened up to more options than Simulation and NEIWorks there are many other good packages available.  I will leave that up to Jeff to open it up if he sees fit.
                                    • Re: Simulation vs. NEIWorks

                                      Wanted to thank everyone for their comments and suggestions.  Very helpful.  I'm playing with a trial version of Solidworks Premium this week and also downloaded 2010 to check out the enhancements to Simulation Xpress.  I've only scratched the surface with both.

                                       

                                      I am more than open to anyone's thoughts on alternate packages.  I stumbled upon NEI Works while searching for reviews on the various Solidworks FEA options.  I am aware of several other packages, Mechanica and ANSYS but don't have experience with either.  I priced out the upgrade to Solidwoks Premium vs. NEI Works vs. adding Mechanica to my Pro/e seat.  It was easy to rule out Mechanica since I haven't had a client request Pro/e in almost 2 years and it wasn't any cheaper than the other 2 options. 

                                       

                                      What I'm really trying to get a grasp on is the comparative "value" in the various options.  I haven't had the need for anything beyond Solidworks Xpress until recently and I don't see myself becoming an FEA "guru" but it would be nice to have a package with a few more bells and whistles.  If Xpress is a Moped and ANSYS is a Porsche, I'm looking for a Camry and might settle for Kia Rio.  At present, I need to be able to analyze static loads in simple assemblies.  Of course I'd like it to be accurate but I can live with a few percent here or there...

                                       

                                      If anyone has thoughts on low to mid-range FEA packages, other than NEI or Solidworks Premium, I'd love to hear your thoughts.  I'm interested in tracking the discussion on higher-end packages but it frankly doesn't make sense for me to spend that much when I'll likely never need that much power.

                                       

                                      Thanks again for all your thoughts.

                                       

                                      Jeff

                                        • Re: Simulation vs. NEIWorks
                                          Emilio Graff

                                          I have to say I have very little experience with Solidworks Simulation. So far, I've been happy with the very low number of meshing errors I get. The solvers certainly seem well optimized, and but for a few stupid cases, make decent use of multiple CPU's.

                                           

                                          However it seems with Simulation the user interface is but a hack. The linear static simulation (which comes with Solidworks Premium) seems pretty workable. It seems that as the number of users decreases, so does the quality, and it is evident to me that development has little or not testing---only the developers are running the same test case after test case and don't realize what parts of the UI are disfunctional or broken. Simulation Premium is full of stupid problems which mostly seem trivial and only aggrevate the user, making the setup time the most time consuming part. Ideally, you'd set up your studies quickly and easily so you can go do something else while it crunches the numbers.

                                           

                                          A few things off the top of my head (you can look at my other posts for recent problems and complaints):

                                           

                                          1. You can define parts as remote masses. That means they impose loads on what you're analyzing, but don't get analyzed themselves. That's great. Except that it only works on parts, because subassemblies are "dissolved" as far as Simulation is concerned. Have a stack of parts hanging off a beam and you just care about the beam's deflection? Well then you either place the mass in manually, or create a part based on your assembly that has similar mass properties, because it will take forever to go part by part and have them rreated as remote masses.

                                           

                                          2. When analyzing assemblies, I used to just create a new part that was a single solid body of the whole assembly. That's one way to "get around it" for Xpress. Now with the full-blown version I figured I'd try working on whole assemblies, since then the changes I make to parts are already in the models. Well, the UI efficiency does not scale well with number of parts, and after about 40 or so it became unmanageable---even if you omitted most of them from the simulation; everything would simply take too long to respond. It forces you to suppress the parts in the model and save "mouse lag" time. That's fine if you don't actually need them, but it sucks if you do. And why is "suppressing" a part in the simulation not identical to suppressing the model as far as the simulation is concerned? Who knows.

                                           

                                          3. I just ran a linear dynamic sinusoidal simulation (vibration test). I defined an excitation spectrum by listing the response magnitude at different frequencies. Let's not even get into how ass-backward the curve editor is, or the fact that once you save your curve in your database, you can't save it again with the same name (won't even let you overwrite). 12 minutes into the solve (which is almost 30 minutes including meshing), I get an error that says my excitation curve doesn't cover enough frequencies. It turns out the study be default sweeps up to 10 kHz or something and my curve only went up to 700 Hz. There's a missing IF statement if I've ever seen one.

                                           

                                          Sure, you get a subscription, you can create a dozen tickets an hour, like I am doing. Then you are working for Solidworks for free, and you better pay for another 3 years of subscriptions in the hope that they actually implement changes to what caused you problems.

                                           

                                          I'm going to sign up for a class and hope that all this is because I'm a stubborn fool who wants results yesterday. If not, I will immediately start evaluating alternatives. Evaluation in itself is a daunting task if you don't have a prior case that caused you some trouble to really push things. I wish you luck (if it isn't too late already).

                                            • Re: Simulation vs. NEIWorks
                                              Robert Stupplebeen

                                              If you sty linear static then Simulation should work great for you.  You can dabble into nonlinearities (materials, large deformation, contact) however you will quickly find that there are limitations.  My strong preference is for Abaqus for difficult nonlinear problems.  There is a much higher cost however I believe that I more than make up for the cost by increasing efficiency.  Below are some links to threads that might be useful.  I hope this helps.

                                               

                                              http://www.eng-tips.com/viewthread.cfm?qid=234058

                                              http://www.eng-tips.com/viewthread.cfm?qid=242785

                                               

                                              Rob Stupplebeen

                                                • Re: Simulation vs. NEIWorks
                                                  David Anderson
                                                  just a note that to perform large deflection or use nonlinear materials or contact (other than bonded), you will need a nonlinear solver which is often an upgrade for most packages.
                                                    • Re: Simulation vs. NEIWorks
                                                      Joe Galliera
                                                      Great point, David!  Since most SolidWorks users are creating assemblies, our Simulation tools wanted to excel at assembly analysis.  The large displacement and contact conditions are two major parts of that ideal.  I also love how Simulation has Connectors, such as bolts, springs and edge welds (new for 2010), that makes working with assemblies so much easier.  Does anyone else remember the pain that it took to define the pre-load on a bolt, let alone setting up the bolt itself, with what I call a "traditional" FEA tool?
                                                  • Re: Simulation vs. NEIWorks
                                                    Joe Galliera
                                                    Attached are documents pertaining to the verification of frequency analysis with Simulation.  It was interesting to me that the beam mesh did the best job because that most closely represents the theoretical approach.
                                                    • Re: Simulation vs. NEIWorks
                                                      Derek Bishop
                                                      Emillio, having used Simulation for several years now I can confirm that you are spot on with your assessment of the software. The biggest problem is the time wasted reporting the numerous software bugs and finding work arounds. In my opinion many of the problems are the result of putting out software that has not been properly tested and debugged.
                                                        • Re: Simulation vs. NEIWorks
                                                          Emilio Graff

                                                          There are several painful factors to Simulation's problems:

                                                           

                                                          1. Reporting the bug is obviously not enough. You must be willing to invest the time in creating a test case or letting them log in to your computer, especially because a lot of problems seem to occurr when your assembly is huge. Solidworks obviously makes no efforts to create large assemblies for internal testing. They probably test most things with a beam, or a couple of beams with a bolt, etc.

                                                           

                                                          2. Some of the bugs/errors are so stupid that it is obvious it was never tested by anyone. For example, in a linear dynamic (frequency response) case, you can choose to calculate displacement, forces, and stresses (any combination of the three). I chose to calculate only displacement, because it's all I cared about. The result? The software goes through all the calculations anyway. In my case, it was 45 minutes for displacement, and 45 minutes for stress. Mind you that these calculations are the easiest case of parallelization one can imagine (you're essentially running a separate FEA case for each frequency around each resonance), yet Simulation only uses one processor for each and of course has no facility whatsoever to run multiple cases simultaneously. Even though the displacement and stress calculations are separate processes, I feared killing the stress calculation in case Solidworks then decided that no results were available at all and I would lose 45 minutes. This is a clear case of a missing "if" statement somewhere that should check the state of those check boxes.

                                                           

                                                          3. Even the stupid errors, which at worst should be fixable with two full days of a programmer's time, won't get resolved for months. There's no way to get a status on anything unless you bug your VAR. The whole enhancement request system is inefficient and badly advertised, if you ask me, and they depend too much on people knowing how to post them in such a way that they will show up with the proper search so people can vote on them.

                                                           

                                                          4. In the mean time, we are paying for a subscription, and have to put in the extra time of bug reporting/test cases/instructions to reproduce errors, all in the hope that within your lifetime they will fix something. Granted I have only recently begun using Simulation Premium so none of my bugs or enhancements have been addressed. But many that I reported had already been reported, and let me just say, the stupid ones better get resolved with SP5.0.

                                                           

                                                          5. Without proper test cases generated internally, errors don't get caught until it's late in the game. That is why SP0.0 is such a disaster. Honestly, how many people are going to start running their current projects through the beta of the next version (whose saved files are not compatible with the previous version) and start reporting problems? So testing is limited to people drawing beams and cylinders and that's that. I personally would consider using SP2.0 the greatest risk I'm willing to take with a real project. If you hit a wall you're at their whim to get it fixed, or you start over with your previous version.

                                                           

                                                          6. Simulation is, of course, what suffers the most because it has the narrowest user base. The result is ridiculous defaults(I define an excitation spectrum that goes up to 700 Hz; 20 minutes later I get an error that says I'm requesting response results for frequencies above my excitation specification; after exploring I find there's a setting in a different window that limits the response range---why not just use the limits of the curve I just put in?), stupid errors (meshin failed; execute the FEA process anyway, just to get a fatal error or a crash), and a whole lot of wasted user's time that the users are paying for---one way in productivity, and another in paying a subscription for the right to test software.

                                                           

                                                          All the problems I ran into during my first week using Simulation Premium would probably take two or three full days of WebEx and Solidworks Rx to just get the ball rolling. I don't know when I'll find the time to do it.

                                                           

                                                          Maybe Solidworks should hold a design contest for cash prizes, and state in the rules that the winning models will be used by Solidworks for testing purposes. For $10k, I'd build something complicated. After a few years they'd have dozens of test cases from a variety of users, and that's probably the equivalent of a dozen of us having to do real work and running into ridiculous problems.

                                                            • Re: Simulation vs. NEIWorks
                                                              Emilio Graff

                                                               

                                                              Maybe Solidworks should hold a design contest for cash prizes, and state in the rules that the winning models will be used by Solidworks for testing purposes. For $10k, I'd build something complicated. After a few years they'd have dozens of test cases from a variety of users, and that's probably the equivalent of a dozen of us having to do real work and running into ridiculous problems.

                                                              Hell, they could use all the entrants' models for testing. In one year they'd have more test cases than they've ever had. And what about the models in the splash screens? I think if they were using them for testing they would have solved some of these issues already.

                                                               

                                                              Corel's design contest attracted a huge number of users, and the winner used to be the cover of the box (I don't know how it is now). The results are incredible---once in a while you'll see photorealistic art done entirely in vector graphics. http://www.corel.com/servlet/Satellite/us/en/Content/1231434231476

                                                               

                                                              The first design contest was invaluable to the company as to what features to add in the next version. And I'm sure they are still learning to this day.

                                                               

                                                              Hell, pull out all the stops, and just pay users for successfully sticking to a reported bug from report to resolution, providing Rx files and WebEx time. It could even be credit toward the user's next subscription, since inevitably he will need to pay for it to see any results of his work anyway.

                                                                • Re: Simulation vs. NEIWorks
                                                                  Emilio Graff

                                                                  I just tried to put my money where my mouth is and create an Rx file. The error I'm getting now is that in Solidworks Standard, I load an assembly with three mates, all of which are broken (as a consequence of replacing a subassembly created from a STEP file and thus losing all mate surfaces). I delete all the mates, and I'm left with the yellow triangle icon over the mate icon, even though there are no mates. Rebuilding does nothing.

                                                                   

                                                                  Rx has the option of recording "video" (whatever that means) of what you do it. I type in all the information (which is supposed to include instructions on how to reproduce it) I reproduce the problem, and then it won't let me save the package because I must include the files I was working with. Too bad they are proprietary.

                                                                   

                                                                  So:

                                                                   

                                                                  1. Type in directions on how to reproduce your problem.

                                                                  2. Record yourself reproducing the error. I wish you could send them a recording of you typing it. Then you could record yourself typing it again in your VAR's system, unless you open up a notepad window and copy-paste. You could record that too, I guess.

                                                                  3. Oh wait, make sure you actually recreated a non-proprietary test case that duplicates exactly the behavior you're seeing with your actual project.

                                                                   

                                                                  I wonder what this Rx file actually includes that helps them do anything, other than your own Solidworks files and an instructional video (with user-provided subtitles, apparently).

                                                                    • Re: Simulation vs. NEIWorks
                                                                      Derek Bishop

                                                                      Emillo, you are getting the idea but are only part the way there. The next step having convinced your local VAR that you have a problem and then getting the Rx of the problem through to Solidworks and the problem logged, is to get it fixed. There is no guarantee SolidWorks will fix the problem. I've got a large number of SPR's still outstanding from 2010 Beta testing. Last count was around 40. I've seen many other problems that have been around for ages. Have a look at the problems associated with inserting parts into a part, BOM and Cutlist tables and the myriad problems with Routing. Then there are the problems we have with Simulation. How quickly your problem gets fixed seems to depend on market forces. If you are fortunate it will be addressed in the next software upgrade.

                                                                       

                                                                      Getting the SPR you posted fixed doesn't guarantee that all the problems associated with that SPR will be fixed either. I've noticed that there is often more than one problem associated with a buggy feature. Incases I've witnessed little attempt is made by SolidWorks to identify and fix these other problems unless they are explicity identified by users.

                                                                       

                                                                      I like to think of it like buying a new car and discovering that it has many mechanical and electrical problems. Imagine this and finding that it is your responsiblity to explain in precise terms in a format acceptable to the manufacturer exactly what went wrong . And then having done this the manufacturer refuses to accept a problem existed because they cannot replicate the problem even though you've had numerous breakdowns. Imagine that having found the problem and the seller acknowledging a problem exists finding they refuse point blank to fix it or defer fixing the problem for a long period of time.

                                                                       

                                                                      Am I the only one who thinks there should be laws against selling software like this.

                                                                        • Re: Simulation vs. NEIWorks
                                                                          Emilio Graff

                                                                          Derek---great analogy with buying a "lemon".

                                                                           

                                                                          And as illegal as it should be, software will always be buggy and service packs/fixes will always be a necessity. But what is fundamentally wrong is the subscription model, in my opinion. Because essentially the model is:

                                                                           

                                                                          1. Charge the customers to report problems. Some of these problems are legitimate bugs, i.e., problems that slipped through testing. That's fine, and an acceptable reality. But there is a significant number of problems that are due to untested or unfinished software. This is undoubtedly shown by the number of just outright stupid issues with the Simulation products. The price you pay doesn't increase the quality, it only decreases the user base, and thus the testing team.

                                                                           

                                                                          2. Demand the customer report problems in a specific way. This is unavoidable, because without structure unclear reports like "I click on that button on the top left and it doesn't do anything" would be even easier to create---and they don't help anyone. I would dare say, however, that most problems occurr in "real" assemblies that are large and complex, and company policies/NDAs whatever certainly prevents me from sending them in for support. So customers like me are forced to spend the extra time to recreate the problem in a simpler assembly to report a problem. Moreover, the fact that you have to describe how to arrive at the problem *and* record a session (apparently with screen-capture video) just feels like a waste of time. Without incentive of any sort (such as points towards a free subscription), it's hard for me to justify spending the time---if it's not a critical problem, I will find a workaround, and if it is critical, it won't get fixed in time, so what's the point?

                                                                           

                                                                          3. Charge the customers to obtain fixes to the problems they reported. No software should charge for service packs. Not only that, if you want to see the fruits of your Rx labors you may have to pay subscription for years waiting for a fix. Essentially, the model treats updates the same as new versions (a subscription bought in 2009 SP4.0 will last you approximately through 2010 SP4.0). However, in terms of development, new versions are not treated as service packs; i.e., 2010 SP0.0 is almost guaranteed to be buggier than 2009 SP5.0. That means if I ever have a choice I will never buy a subscription until SP5.0 of that year is released.

                                                                           

                                                                          There is one other piece of software that charges for updates that I know of. ZEMAX is the "Solidworks equivalent" of the optical design world, and a seat costs a bit less than a seat of Solidworks Standard. Yes, there are bugs, and incomplete features in each version. But when you buy the product you get a year's worth of support and updates (that is, "subscription" is included). There is no distinction between new versions and "service packs", that is, new features can roll out at any time. Renewing support costs 25% of the initial seat cost, and there is no penalty for letting it lapse (that last policy is certainly a bonus).

                                                                           

                                                                          As a start, either Solidworks should do away with the separate subscription and just roll it into the price of the seat, or they should allow people without subscriptions to officially report bugs.

                                                                            • Re: Simulation vs. NEIWorks
                                                                              Jim Steinmeyer

                                                                              And I sit here reading the entire post while waiting for my simulation to run only to have it spit out a warning about fixture/force conditions not being right. OK......which one is wrong? What is worng with it?

                                                                               

                                                                              Oh well I will just make some random changes and wait another 1/2 hour.

                                                                                • Re: Simulation vs. NEIWorks
                                                                                  Emilio Graff
                                                                                  Whatever you do, don't spend $2k on support so you can tell them this problem exists, because I already did, and, instead of working on it, they made sure to send me an email asking if my recent experience in changing my email address was ot my satisfaction.
                                                                                  • Re: Simulation vs. NEIWorks
                                                                                    Joe Galliera

                                                                                    Jim, good analysis practice is to first run with Draft quality (first-order elements) to make sure that your analysis problem setup will run correctly.  While not the most accurate for most problems, it will run much more quickly than the default High quality elements.  Second, if you are trying to figure out how to restrain the model, first run with the Soft Spring option turned on (this will give it just enough rigidity to run) and then animate the results to figure out the remaining rigid body directions that you need to constrain.  After you think you got it right, you will want to turn the soft spring option off.

                                                                                     

                                                                                    Support should give you direction, like this, in helping you with your analysis issues.

                                                              • Re: Simulation vs. NEIWorks
                                                                Emilio Graff

                                                                By the way. You know how you can do math in the edit boxes in Solidworks? For example, you can enter 1.5/2 in a dimension and it comes out as 0.75.


                                                                Well, you can't do that in Simulation, which has a total hack of a user interface. So after your boss shells out $15k for it, make sure you tell him you'll need another $20 for a calculator to:

                                                                 

                                                                1. Enter numbers you can't divide/multiply/add/whatever in your head.

                                                                2. Measure angular displacements, since obviously no one does torsion simulations so why would SolidWaits Stimulation allow you to view displacements as angle about an axis?

                                                                 

                                                                Enjoy. I know I do!

                                                                  • Re: Simulation vs. NEIWorks
                                                                    Kevin Quigley

                                                                    Interesting discussion as I'm in the process of looking at buying into FEA now. Here's how I look at it. NEI Works in the UK, for the full on non linear package is about £3300 or so. To get the same functionality for analysing plastic materials (and that is plastic as nylons, ABS etc) in SolidWorks Simulation I need to upgrade my Solidworks Professional seat to Simulation Premium.....which costs something like £14k.....then there is maintenance.

                                                                     

                                                                    I've yet to run any benchmarks myself but suffice to say I have asked a lot of FEA experts for opinions. They all say the same thing. Most FEA systems on the market give comparable results (comparable within set margins for error) except Algor.

                                                                     

                                                                    I'm a product designer so my use of FEA is "classic" CAD vendor sales pitch - as part of the design process. What I want from it is a good indicator that I am on the right track so that I can accelerate time to market and reduce the number of prototype iterations required. FEA will not replace prototypes and anything really complex will get sent off to the real experts to handle anyway. So in this environment - implementation cost is critical, and to me, on paper, that price differential is very hard to ignore.

                                                                      • Re: Simulation vs. NEIWorks

                                                                        You will probably need to factor in the cost of a good pre and post processor, like Femap.

                                                                        • Re: Simulation vs. NEIWorks
                                                                          David Anderson

                                                                          kevin,

                                                                           

                                                                          what sort of analysis are you intending to run on these plastic components?

                                                                            • Re: Simulation vs. NEIWorks
                                                                              Kevin Quigley

                                                                              Waht I am looking at is design stage FEA for reasonably complex plastic mouldings that flex (think like a plastic chair that flexes as you sit back in it). Ordinarily I would consider linear static to be OK, but the design criteria is to allow a large deflection. For this reason I am not sure that the Simulation in Premium (for example) would suffice as the analysis in that assumes small deflection. My VAR has told me I'd need to go up to the "proper" simulation packages and to be frank the cost of doing that is very hard to justify.

                                                                                • Re: Simulation vs. NEIWorks
                                                                                  Bill McEachern

                                                                                  The problem you describe is well within Simulation premium's capabilities - if the material is linear you can even do it in the linear static package as it supports a fully automated force controlled NL solution.

                                                                                    • Re: Simulation vs. NEIWorks
                                                                                      Kevin Quigley

                                                                                      I'll take your word for it Bill, I'm only going on what my VAR said (and they referred the example files I sent to SolidWorks UK). Yes they did recommend Simulation premium but that is way over my budget.....as I said, you seem to get a lot more bang for your bucks with NEI Works.

                                                                                       

                                                                                      EDIT - just checked out your website Bill - if I could buy SW Simulation at those prices I would be very happy! It is aquite a bit more expensive here in the UK!

                                                                                        • Re: Simulation vs. NEIWorks
                                                                                          Bill McEachern

                                                                                          yeah the European and Asian pricing is higher. Anyway I if you do not need NL materials you can probably do it SWX Premium. It isn't the whole NL suite but if the problem is well behaved - stiffness changes relatively gradually with deflection (which is what you would want with a chair back I would think) you should be able to get a decent estimate. Though, you only get the final load step as output and it is a linear interpolation of that data set that you see in an animation. In the NL code you actually see the individual load steps as output. The difference can be less that subtle in some application but  for yours it would not be an issue.