Update for 2022. The capabilities of both these tools continues to evolve, and this post is showing signs of aging. Do not count this unmaintained post as truth, but it can still be a starting point for discussions with resellers of these products.
Update for 2019. The Simcenter branding has extended to Femap with v2019.1. Read more here. As a clarification, the previous article is about the difference between Femap’s “Simcenter” and NX’s “Simcenter”.
Somewhat confusingly, Siemens PLM Software sees fit to field two products that seem like they do the exact same thing. They both pre and post-process FEA. So how comparable are their capabilities? That’s what I’ll attempt to answer using experience as an active stress engineer and former reseller of both products.
First, let’s set the stage. What is Simcenter? Here’s the official Siemens video for getting you acquainted:
Ok, that was almost completely useless, right? Here’s the real deal: Simcenter is the title of a new Siemens product that combines the functionality of NX’s modeling and advanced simulation environments. NX is at it’s core a CAD program, based on a legacy product called Unigraphics. With the addition of different modules serving industry sectors such as FEA and manufacturing, the program today is referred to as “CAE” (Computer Aided Engineering). Simcenter is essentially a cut-down form of NX that is geared towards simulation, hence the name. The Simcenter 3D product is intended to be a start to finish package, integrating the Siemens PLM Software-owned portfolio where the user can leverage NX CAD capabilities to turn designs into analysis via FEA (LMS Samtech/ Virtual Lab, NX Nastran) and/ or CFD (STAR-CCM+).
What is Femap? I bet you already know, but if not, read more at my dedicated page here.
Both of these products are typically used with the same solver, NX Nastran (though both can interface with others). If you’re a guy that floats between design and analysis, the NX Adv Sim/ Simcenter workflow may work best for you. If your sole duty at your company is structural analysis, Femap is likely the better option. In rare instances of certain power users, you may be best served by use of both programs.
To help you understand which product you may need, I’ve created a table demonstrating the pros and cons of each by category. This will help you make your decision depending on how important a particularly category is to you. Use the contact form if you are comparing these packages for purchase and want some more clarity on the differences.
↑ = Program has the leg up
↔ = No difference
↓ = Program is deficient WRT the other
|Femap||NX Advanced Simulation/ Simcenter||Comments|
|Price||↑ Advantage goes to Femap. Femap's baseline cost is less than NX with advanced simulation or Simcenter. Those programs have features that not all analysts need, especially those unrelated to FEA.||↓ More expensive||Rating is relative between just these two offerings.|
|Geometry editing||↔ Includes all of the commands you would use for FEA. A learning curve exists for those new to FEA preprocessors.||↔ Based on CAD, so the range of commands is geared towards designers and not analysts, though it is very powerful. A learning curve exists for those new to CAD.||Such features are needed to prepare geometry for meshing.|
|0D/1D Meshing||↑ Intuitive dialogs and various functions to assist with generation of these elements||↓ Cumbersome to set up||Rigid elements, spring/ cbush elements|
|2D Meshing||↑ 2D meshing is what Femap is best at||↓ Adequate capabilities here but not as developed as Femap||2D meshing is the dominant approach for larger structures|
|3D Meshing - Creating Tetrahedral elements||↔ Adequate capability||↑ More capable than Femap due to the ability to transition to hex elements.||3D serves smaller single part FEMs, and breakout models. Tets are less accurate than hex elements for stress.|
|3D - Creating Hex elements||↓ Requires "slice and dice" method, which is often difficult to debug when it fails.||↑ Powerful Mesh Mating Conditions functionality and 3D sweeper. |
Hybrid hex/tet meshing. Automesher can even facilitate transitioning between hex and tet meshes via pyramid elements.
|3D serves smaller single part FEMs, and breakout models. Hex elements give superior stress results (given sufficient resolution and quality).|
|ID numbering management||↑ IDs are fundamental to Femap select methods, so IDs are right at the forefront of Femap operation. Many functions like Model Merge and Tools, Parameters to assist with keeping numbering under control.||↓ Dialogs do not use IDs as a selection method.||Very important in the analysis of larger structures with multiple analysts.|
|Assembly modeling||↔ - Many features to assist with setting up glue or contact connections.||↑ - Can link mesh associated with multiple instances of a part.||Features that lends themselves to assemblies that can be intricate or hold common parts.|
|Program speed||↑ A lighter-weight program since the focus is FEA only.||↔ Adequate, but some commands take some time. The "waiting" dialog box is a familiar sight. Takes some time to load different menus to the screen.||Speed of menus, dialog, enacting model changes, etc.|
|Programming/ Scripting||↑ Can be done within the program.||↓ Requires separate IDE||API scripting, automation of commands|
This is meant to be a living document. I will update it as I realize new information to add.
Excellent comparison of both products. I’ve not used FEMAP. However coming from Hyperworks environment to NX Nastran/Simcenter I find it rather painful in those areas you highlight as weakness compared to FEMAP. This makes me to believe FEMAP is the real competitor to Hyperworks. Hopefully the company I use can switch to FEMAP by highlighting this comparison.
Any comparison on the post-processing side? I find NX Nastran post-processing extremely bad and cumbersome.
Thank you Cris. I have not used Simcenter for post-processing. That is due to my familiarity and preference for Femap. I would bet that Simcenter is not as capable wrt Femap or Hypermesh. Admittedly, I have not used Hypermesh. It seems to me like that product is more popular in the auto world. Hypermesh does seem to be more akin to Femap than Simcenter as an FEA pre/post-focused product. Reach out on the contact form and I can help you get an evaluation copy of Femap to trial at your workplace.
Which versions of each were used for your comparison? I ask because NX 10 does allow you to select based on Node or Element IDs.
I think this was NX 10. If what you say is true, then I suppose I could add to my point that it’s not the primary means of selection. IIRC, you select objects and don’t necessarily see the IDs by default. Let me know if I have that wrong.
Excellent comparison of both products. have used both , value for money is with FEMAP . The result match with actual are similar in both the cases. In case of NX you require more skill , but in FEMAP one can get expert in shorter time compare to NX.
Can you also put comparison with competitor, most of client used ANSYS, feel results are better in FEMAP , but the time and cost is better in it what come to know. It may be my perception , also depend the result i have seen