When the idea of doing a course in Ansys struck me I was thinking about learning the tools of Workbench. For me Ansys was all about workbench. But while starting the class I found out that we started with APDL. This disturbed me. I couldn’t understand why we were learning APDL when workbench was easier to use and more user friendly. My initial conclusion on APDL was that it was just a primitive version of Ansys that was in use before workbench has come and that Ansys has continued keeping it along side so that the older users might be able to use it. But then why was I taught APDL first before workbench if it was the older version. So I concluded that there was more to APDL than just an outdated tool of Ansys. This is why I started off to find the difference between the both. Below listed are some of the differences I found:
1.Graphical User Interface
Workbench has a better graphical user interface compared to APDL. Workbench is also more intuitive as compared to APDL. The user can just go through the different options and understand what the different icons mean easily.
2. Use of memory
Since WB has higher graphical user interface compared to APDL it takes up more computer memory for the same operation performed. Thus we find that WB is more resource intensive.
3.Ease of use
The interface of workbench is intuitive and much easier to use. It has many of the settings already built in and there is no reason to provide these. For example many of the generally used materials are readily available and can be just selected but in APDL we have to give in the properties of the most common materials even. The other use is that we do not have to select the element type according to the problem type. WB automatically selects them according to the type of analysis, but in APDL we have to know the best element that suits our purpose and select it accordingly.
4.Amount of control
APDL gives a very high degree of control to the user regarding the problem. The user has to specify each and every step of the problem manually thus the user is aware of everything that APDL does. But in WB as seen in point 3 many of the parameters are chosen by the software in the background. So we are not able to control every aspect of the problem.
5.Undo option
APDL does not have an undo function as workbench. If an error is committed in giving boundary conditions or forces we have to manually delete it using the delete tool in the menu. The delete tool is very difficult to use. But in workbench we can just press Ctrl+Z or right click on the boundary condition or force and just select delete from the drop down menu.
6.Interacts easily with other CAD packages
APDL allows importing of only step or iges geometry files for analysis. But workbench supports files of catia, solidworks , etc also. Thus we do not have to waste our time converting a model into iges or step. This is particularly helpful when we have to bring about corrections in the model.
7.Possibility of error
Workbench has higher probability for error since it gives results even if we do not know what we are doing. It solves the problem even if the input values are not correct. For example even if complete boundary conditions are not given it gives weak springs in certain cases to solve the problem.
8.Complex problems
Although WB is easier to use APDL helps to solve complex problems. Problems where the material has a very particular behaviour. Example it is very easy to specify the properties of different layers of laminates using APDL but in workbench we have to use an additional module called ACP for the same. Another example may be defining Tertiary creep equations for materials. APDL is the only one that can do the user defined non-linear tables, or equations for the material definition within the simulation. WB is useful for general problems that are defined already in WB as components but to simulate out of the box problems APDL is the go to person.
9.Materials Repository
WB has a dedicated repository of general materials and materials that are used for specific applications. But APDL does not have any such thing. In APDL we have to define each and every material we use in a particular simulation even if it is structural steel. In this case WB is a real time saver. The point 8 also highlights the advantages APDL presents material wise.
10.Coupled analysis
APDL does not allow coupled analysis. Thus after a particular analysis we have to manually take down the values and input these for further analysis. But WB allows coupling of different analysis like thermal and structural etc. This helps us to seamlessly share the results from one analysis to the other as input without effort. It helps to simulate real world problems without manual effort from user part saving a lot of time.
11.Checking mesh quality
Although workbench allows us to check the quality of mesh, it ignores bad meshes to continue giving results. This results in poor quality of results. But APDL will not proceed to the results if the mesh is inappropriate. Thus APDL assures meshing quality.
12.Geometry creation
Only very simple geometry can be created using the APDL modeller. It is near to impossible to create complex geometry. On the other hand WB has a fairly good interface to create complex geometry. But still FEA engineers prefer to use external CAD softwares to create the geometry.
13. Geometry correction
WB has a very good geometry editor which is able to work with complex shapes. Up to a point design modeller in WB can also be used to design complex shapes, but mainly it is used to correct the imported model for better meshing and boundary condition assignment. But the modelling tools in APDL are very primitive and do not encourage imported model correction.
14. Use of command
Problems in APDL can be completely executed out using commands. Once we learn to work with commands this can be a real time saver. Some actions in WB do not have tools and make use of commands to execute them. Usual problems in WB are not executed completely using commands.
15. Ability to codify a problem
This is one of the best advantages of APDL. In APDL we can create a batch code in a text file and rerun the text file in APDL. If the code has problems or a specific part needs to be changed ( like the force or the material ) you can change the code in the text file and run it again very quickly. This cuts down time on troubleshooting and rerunning similar problems with different input. WB lacks such a capability.
16. Mesh tools
WB has very advanced mesh control tools. These can be used to mesh the model according to the complexity of the geometry. Although WB does not promote the selection of mesh elements it helps us to control the manner in which the automatically selected mesh elements are distributed over the model.
17. Presence of modules
WB has a large number of pre-engineered modules. Modules have been already built in for the different real world problems. So once we identify our problem we can find out which module is used for our purpose and carry out with our problem. But in APDL there are no such pre- engineered modules. We have to define the type of problem we are going to simulate and define the suitable settings.
So basically WB has most of what APDL has but lacks the more specialized stuff. WB is constantly evolving over the years to develop into a very powerful tool but APDL seems to be pretty static. The limitations of WB in analysis capabilities are being solved. Recently it has been possible to solve problems by using WB and APDL ( known as MAPDL ) so that we can utilise the strength of both for problem solving.
Note: I have tried my best to cover all the information regarding the topics. I am open to feedback and would appreciate if the other designers could enrich the article by sharing their insights, experiences and knowledge through the comment part.
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