Finite element analysis is a very widespread numerical technique in the development of new products with high added value or responsibility. This technique refers to a multitude of industrial applications, although perhaps the best known is its application to the calculation of structures, as it is the first field of application and also where it is most intensively used.
The first software for finite element analysis was developed by NASA in 1965, NASTRAN (NASA STRUCTURAL ANALYSIS PROGRAM) within a project financed by the American government to carry out structural calculations in aeronautical and space projects. There are currently numerous structural solvers available to perform finite element analysis, including NASTRAN, Abaqus Standard and Ansys as implicit solvers and Abaqus Explicit, LS-Dyna, PamCrash and Radioos as explicit solvers.
SOFTWARE FOR FINITE ELEMENT ANALYSIS
At ICEMM we always work with the leading simulation software tools, and currently have licenses for Abaqus Standard/Explicit and MSC Nastran for finite element analysis applied to linear and non-linear structural analysis, implicit and explicit dynamic analysis, fatigue and fracture analysis, and thermal analysis.
The application of the finite element method is not exclusive to structural analysis, but has applications in other areas of simulation such as CFD analysis (Computational Fluid Dynamics), acoustic analysis and electromagnetic analysis, although it is true that for CFD analysis it is more common to use techniques based on the Finite Volume Method, FVM (Finite Volume Method).
At ICEMM, as part of our strategy based on innovation and the search for new technological challenges, we have begun to develop acoustic simulation projects to help industry reduce the acoustic footprint of their developments. To this end, we have Actran, the leading acoustic simulation software on the market. Actran is a finite element analysis software that allows us to efficiently solve problems of acoustic propagation, vibro-acoustics and aero-acoustics in the entire frequency range.
HOW DO WE PERFORM OUR FINITE ELEMENT ANALYSIS AT ICEMM?
The process we always follow at ICEMM when we have to perform a finite element analysis is to meet with our client to assess the suitability of the method to the problem to be solved.
It is important to identify with our clients if the method is applicable (it is not always the most appropriate, especially if the problem can be solved analytically, which is much easier, cheaper and just as reliable), to establish the hypotheses to be made and to study the inputs available (on many occasions it is necessary to simplify the analysis, always on the side of safety, due to lack of data). It is also important to assess the level of responsibility of the study, as the quality standard is not the same in the aeronautical, nuclear, or civil engineering industries as it is in the photovoltaic industry, for example.
Once the scope of the simulation has been defined according to the above points, we can start working on the simulation model. To perform the finite element analysis, in addition to having first class solvers, we will need to determine the following points:
- Pre- and post-processing tools: the creation of the finite element model consumes a lot of resources in terms of engineering hours in the pre-processing phase, which impacts the development cost. To optimise these times at ICEMM we have the best meshing tools available. For complex geometries we use Hypermesh, and for simpler geometries we use Abaqus CAE. We are currently introducing Hexagon’s MSC Apex, a tool that has pleasantly surprised us in geometry cleaning and meshing tasks, and which will complement our current capabilities.
- Mesh size and type of elements: on this point, many bibliographic references talk about the sensitivity studies that need to be done, both for the mesh size and the type of element depending on the problem to be studied. This process, which is correct, involves a high cost in terms of time and resources. However, at ICEMM and after 18 years of experience, we have established our own procedures based on our experience and on the procedures of large aeronautical and automotive companies, which allow us to predefine these parameters, allowing us to optimise the associated costs. In our blog you can read a couple of posts on these topics:
- Loads: one of the key points in any finite element analysis, if the loads are wrong, the finite element analysis will also be wrong. In this section we advise our clients to correctly define the loads to be applied, either because they are defined by regulations or because they must be calculated beforehand as they depend on the behaviour of the structure (dynamic loads) or because they are coupled with it (aeroelastic loads).
- Boundary conditions: this point is a priori simple to define, however, we find many errors in external reports due to lack of experience of the engineer who is carrying out the study. As with the previous point, if the boundary conditions are wrong, the results of the finite element analysis will also be wrong. The boundary conditions must be defined according to the real constraints and, if they cannot be represented, always on the safety side.
- Materials: the difficulty of defining the materials correctly is related to the complexity of the finite element analysis we want to perform. If we are doing a linear analysis with isotropic materials, it will not be difficult to define the material correctly, as we have extensive databases with the necessary data. However, if we want to define non-linear behaviour of the material, depending on time, temperature or strain rate, composite materials, damage or fracture, then things change because often the properties are not defined in any database and we have to use contrasted technical publications or carry out tests on the material.
IS IT EXPENSIVE TO PERFORM A FINITE ELEMENT ANALYSIS?
The answer to this question depends on what the client is looking for. If you just want a simple report with “colours” to cover the dossier of some development and carried out with a “simple” finite element software, the answer is no, you can find very cheap studies. In this case ICEMM is not the supplier you need.
If, on the other hand, you are looking for a quality finite element analysis that meets your requirements and gives full confidence in the results obtained, the cost of the finite element analysis can be high, although it will always depend on the scope of the analysis.
It should be borne in mind that in these cases very expensive finite element software licences are incurred in the region of €20-22,000/year for a first level FEM solver with a single core (if we have very large models we will have to use more calculation capacity to obtain results in reasonable time and acquire more licences), plus €14-15,000/year for a quality pre-processor, plus the calculation machine (€20,000 for a medium-high power server with 2 sockets) plus the engineering hours.
It is important to note that large simulation models, such as those used in crash analysis in the automotive sector, can require hundreds of cores and tokens (licences) to be able to carry out the simulations in the required time. Nowadays, to tackle these problems, it is more efficient to make use of the cloud computing offered by our technology partners in CAE simulation.
Even with the cost of this type of service, developing a finite element analysis with the quality offered by ICEMM is always a guarantee of return on investment, as it allows our clients to generate more efficient, optimised and safe designs.
ICEMM, YOUR POINT OF REFERENCE IN FINITE ELEMENT ANALYSIS
The excellence of our services is backed by the continuous contracting of renowned industrial companies, both nationally and internationally, such as Airbus, INDRA, Navantia, ELECNOR, SENER, among others. In addition, smaller companies, such as LODEPA or Fagor Electrónica, rely on our services for their projects, consolidating ICEMM as a benchmark in the field of finite element analysis.
It is also important to highlight ICEMM’s experience in other areas of simulation, such as fluid simulation using CFD (Computational Fluid Dynamics) techniques and the analysis of particles coupled or decoupled with the fluid by means of DEM (Discrete Element Method) simulation.
Within the area of fluid simulation, at ICEMM we specialise in thermal analysis, air conditioning (including Data Centres), ventilation and gas evacuation, hydraulics and aerodynamics.
In the area of particle simulation, we have extensive experience in the simulation of processes with particles and in the study of fluidisation of solid particle beds (biomass reactors, for example).
