Mistakes made by CAE engineers???

1) Submission of a job without the proper checking (should be cross checked by ideally 2 CAE engineers):  Checking the work of someone else is a rather boring and not willingly accepted job.  But it is very important and a job of high responsibility.  Checking and rechecking all the details, ensures good quality and minimal mistakes. 
For example, a CAE service providing company submitted a meshing job to their regular client.  Everything was perfect except for the material properties.  The analyst at the customer end was used to error free models being submitted by this CAE team over the years.  He blindly started the analysis without checking the material properties.  At a later stage in the design process, a big difference was noticed in the results of the current analysis and the previous one carried out for a similar model. After checking both the models carefully, the analyst realized the difference in the material properties. Please be careful before submitting your work and check it several times and then ask your colleague to check it as well.  Also, always request that your client check the model in every aspect before starting the analysis. 



2) Import / Export errors : Some of the preprocessors do not export all the elements and boundary conditions that exist, unless special options are turned on or special translators are used.  One CAE group exported a big mesh model with the template set for a specific external solver.  Some of the special elements (RBE3 elements) were not exported due to a translator problem.  These were extra rigid connections and were not resulting in rigid body modes during the free-free check.  The analysis was carried out As-It-Is by an analyst.  Based on the CAE results, the CAD engineers released the drawings and a prototype was prepared.  The test results were not satisfactory and further modifications were suggested.  Updated CAD data was provided again to the same meshing group. The changes were local and it was to be carried out on the earlier submitted model.  By this time, the CAE group had an upgraded version of the pre-processing software and the export operation was 100% successful (all the elements including the ones that were missed earlier were exported properly).  The results for the modified model showed a drastic difference when compared to the original.  After careful checking and comparing the number of elements, the analyst realized that a few rigid elements were missing in the first model.  Hundreds of engineers had worked on the job in the mean time (CAD, prototype, testing, planning etc.).  Who is responsible for this delay and cost?  Is it the analyst, the service provider, or the pre-processing software?  It’s strongly recommended to import the mesh model before submission to the client (in a new file) and apply all of the quality checks as well as compare the number of elements of each type (like number of tria, quad, rigid, spring, mass etc.).


3) Experienced engineers are the best guides and teachers for newcomers and less experienced colleagues:  CAE engineers are usually highly qualified (education wise) and having years of experience means that a lot of know-how and knowledge is available within the team.  The best teachers for newcomers in any organization are undoubtedly the senior engineers working in the same group. Software trainers or consultants do not know exactly what is required by the customer.  Every company should encourage and pay special incentives for experienced engineers to share their knowledge with the newcomers. 


4) Meshing is considered as low level work, post graduates and PhDs are reluctant to spend time on meshing:  Sometimes a dangerous trend is observed among post graduates and PhDs. They feel meshing is a low level job and being highly qualified, they should not waste time in such low level work.  A building cannot be built on a weak foundation.  Meshing is the foundation of CAE.   At least in the initial years, analysts should be encouraged to mesh the components.  


5) CAE engineers are reluctant to visit the shop floor, testing department, or field  to study the  manufacturing, functioning, and failures of the components:  Just sitting in front of the computer in an air-conditioned office and submitting nice analysis reports is not going to make the analysis successful.  What is absolutely necessary is to regularly visiting the test department, observing the components on the structure, and comparing the real life performance with the computer model. These days, many times a CAE team is located in a different country than the manufacturing and testing facility.  The quality of the CAE work would be much better if there is an opportunity to know the product, manufacturing process, testing and on field behavior. 


 6) Providing basic training related to data acquisition and testing:   At least a basic training on the data acquisition and testing methods is strongly recommended for CAE engineers. 


7) Unnecessary emphasis on modeling the minute details without giving due consideration to available time, hardware, and software capabilities:  Finite Element Analysis is an approximate approach.  Modeling the things to the minute details without giving due consideration to the capabilities of the available software and hardware could unnecessarily complicate the problem. For example, when analyzing a structure and the failure is expected at the body, a bolt should not be simulated by modeling the minute details like threads.  Instead a beam element and connections using rigids in the washer area could adequately model the bolt ( in the linear static domain).  

8) Loyal to specific software and a resistance to learn and use new ones:  Engineers using a specific software for years, are not willing switch to other one.  No commercial software is perfect and every software has its own plus and minus points.  In the service industry, what matters most is the time and quality of the work.  If a specific software is good but takes more time in comparison to another one for some specific application, then it is better to use the better one.  Sometimes a combination of two different software works faster.  For example, meshing in one software and then performing quality improvement or remeshing in other.  A CAE engineer should be loyal to his/her duty rather then a specific software. 

9) Not the CAE engineers but the design engineers are the most important person in the design chain:  CAE Engineers are usually highly qualified, paid higher salaries and sometimes it leads to a superiority complex (that they are the most important people in the design cycle process).  But it should always be remembered that the Design Engineer is the most important person and the role of CAE engineer is to provide analysis services to him/her (other service providers are test, purchase, manufacturing, etc.).     

10) While suggesting the modifications, no consideration for  the manufacturing constraints and the cost effectiveness:  Sometimes the CAE engineer gives suggestions which are either not manufacturable or cost effective.  For example, it is very easy to increase the thickness of the parts showing a higher stress, or to suggest that high strength (costly) material should be used, or to suggest geometry modifications without considering the manufacturing constraints.  Sometimes CAE engineers are adamant about their proposals and are not willing to carry out further iterations as per suggestions from the design or manufacturing engineer.