The most complex questions, professionally processed
The deep industry-specific know-how is the key to a smooth processing of your service inquiries.
Our customers appreciate our deep understanding of their often very specific questions.
After a short discussion, our specialists will record your task. We will then suggest practice-oriented approaches from the world of FE-simulation.
In the following you will find some examples of the simulation tasks where we can support you as a service provider.
Short-term and fast processing, well-founded expertise in the machine tool sector
Dr. Hubertus ZeddiesTechnical management, Minda Industrieanlagen GmbH
Bolts strength verifications as a service
Bolted connections are popular components in connection technology, as they are both detachable and do not require the introduction of heat into the components.
However, bolted connections must be subjected to a strength test, as they often play a safety-relevant role.
We calculate for you the static and dynamic strength according to VDI 2230 and DIN EN 13001 for assemblies of any complexity with any number of bolts.
The bolts models used are of high quality (for experts: hexahedral mesh, 3D body with shaft and head, without thread). The thread area is taken into account by the core diameter.
We can consider force, pressure, acceleration, speed and temperature loads in any combination.
Welds strength verifications as a service
Welding as a joining technique is always used when high force transmission with low meterial input is important.
Due to their high safety relevance, welded joints must be subjected to a strength test.
Depending on the requirements and complexity of the assembly, we calculate the static and dyamic strength of welds using the following methods:
- Notch stress method: 3D modelling of welds with notch radius and evaluation according to FKM guidelines.
- Structural stress method (hot-spot): 3D modelling of the welds without notch radius and evaluation according to the FKM guideline and DIN 18800-1.
Weak point analysis as a service
Machine tools, handling robots and other manufacturing machines must meet certain rigidity requirements. Only in this way can the required production quality be met.
With complex assemblies, the question often arises as to which components have the greatest influence on the overall compliance at a given point.
We answer this question by FE-simulation of different expansion stages of the assembly.
Using a classic milling machine as an example, these expansion stages could look like this:
- milling spindle
- milling spindle + quill
- milling spindle + quill + sleds
- milling spindle + quill + sleds + moving stand
- milling spindle + quill + sleds + moving stand + Machine bed (complete machine)
At the end of the calculation, a diagram is created showing the compliance of the individual expansion stages. The largest jumps in the diagram indicate weak points in the assembly. With this knowledge you can optimize your products in a targeted manner. You save time in design, avoid prototype costs or damaging warranty claims.
Stress analysis as a service
Loads cause deformations and thus stresses. Simplified, the stress is defined as the quotient between force and area. However, this simple relationship is only applicable to simple component geometries by the designer. Real components, on the other hand, usually have geometries that are too complex, and finite element analysis is required to reliably determine the multiaxial stress states (tensile/compressive and shear stresses).
Determining the stresses is usually just the beginning. This is because not only stresses above the material yield point are dangerous. Stresses significantly below the yield point can also be dangerous under changing or pulsating loads (fatigue fracture).
The accuracy of a stress analysis depends on several factors:
- Consideration of all relevant attached parts (relevant assembly).
- Realistic consideration of boundary conditions and loads (support points, forces and moments, pressures, temperature loads).
- Optimal FE mesh especially at notches (fillets).
The calculated stresses finally flow into an FKM verification. In the process, the static and dynamic safety against component failure is determined. Load collectives can be taken into account. In the absence of fatigue strength, the operational strength can be estimated.
Thermal Analysis as a service
In many machines, the drives lead to an uneven heating of the individual parts. The resulting thermal expansion causes length changes and internal tensions. A deterioration of the processing quality is the result.
In thermal FE analysis, temperature fields and their distribution in components and assemblies are determined using FEA.
In many cases, the steady state of the temperature distribution is determined (static analysis).
In some cases, however, a dynamic (transient) simulation of the temperature fields is necessary. For example, when the heat source is mobile and the heat input depends on the speed of the movement.
In a second step, the deformations and stresses caused by the temperature differences are calculated. The temperature loads are automatically taken from the previous thermal simulation. Additional loads can also be applied to the structure now.
A difficulty in thermal FE analysis is the correct definition of the boundary conditions. Especially convection and radiation coefficients shall be mentioned here. A correct model can only be developed by a precise understanding of the simulation task and the physical phenomena.
The thermal analysis leads to an improvement in the processing quality of machines.
Sheet thickness optimization as a service
The most effective way to optimize a sheet metal welding structure is to optimize the thickness of each individual sheet or optionally of groups of sheets.
For this purpose, we offer you as a service the automated optimization of sheet thicknesses in your design.
The advantage of this new approach is that we can optimize sheet metal welding designs without significantly increasing manufacturing costs. Also the result of the optimization does not require any interpretation and can be produced directly. Finally, due to the 100% automation, the process is cost and effort minimal. Mathematically optimal weight savings of up to 40% are possible.
After many years of perfecting the dynamic analysis of machine tools, we have developed the chain analysis. We now offer the chain analysis as a service. Due to process automation, the effort required for chain analysis is low. In return, the benefit of simulation in this case is significantly greater than with a classic FE analysis.
Learn more about chain analysis in this article.
Natural frequency analysis as a service
There is hardly any branch of industry where vibrations can be ignored in the development of machines and plants.
If vibrations occur in the vicinity of resonance points, this can have dramatic consequences (self-destruction, human damage).
For this reason, we offer you our many years of expertise in the prediction and prevention of dangerous natural vibrations.
The dynamic analysis of your products typically starts with a natural frequency analysis, also called modal analysis.
Based on the natural frequencies, unexpected improvement approaches can be derived. The often mentioned principle "A lot helps a lot" is thus sometimes overridden.
In practice, this leads to more efficient machines. Milling machines, for example, can produce components faster with the same accuracy.
Frequency response analysis as a service
It is not always possible to avoid vibrations during operation. In such cases it is rather a matter of reducing the vibration amplitude than of completely eliminating the vibration.
The frequency response and especially the compliance frequency response are good tools to characterize the vibration behavior of your products.
By means of a simulative frequency response analysis we can not only predict where, something is vibrating, but also how strong.
In combination with modal analysis, this can be used to derive specific suggestions for improvement for your design.
Coupled controller-mechanics simulation as a service
Today's drives in machine tools and robots place increasing demands on the supporting mechanics. A perfect interaction between control and mechanics is the prerequisite for a powerful machine.
With the help of the coupled controller-mechanics simulation we can directly evaluate and improve the machining accuracy. The result is also illustrative for laymen, because we measure the deviation in µm.
At this point we would like to explain the differences between virtual commissioning and the coupled controller-mechanics simulation:
- Virtual commissioning is a simulation method, which often takes place after the design is completed. The mechanics are considered as "given" and "unchangeable". The controller and the control are adapted to the mechanics.
- The coupled controller-mechanics simulation is mostly used when the mechanics are still in the design phase (changes are still possible). Both the controller and the mechanics are variable and are iteratively adapted to each other. Thus, the optimization possibilities are many times greater.
Impact simulation as a service
Protective fences for robot cells and buffer stops at track ends are examples of constructions for which the behaviour on impact is important.
The behaviour on impact is usually associated with large plastic deformations, so that real tests are accompanied by destruction of the tested components. Therefore the experimental effort is quite high.
With the help of impact simulations we support you in the design of your products. This saves you time and money.
Detailed simulation of ball screws as a service
At first glance, ball screws appear to be simple components. However, the relatively high number of different geometric parameters have a complex effect on service life, rigidity, smooth running and heat generation.
With the help of special FE simulation models, we can reliably calculate these complex relationships in the ball screw drive.
It is not unusual for us to be able to increase the service life of ball screws many times over. We optimize the position of the ball chains, contact angle, number of balls, nut geometry and much more.
Detailed simulation of rolling bearings as a service
The detailed simulation of rolling bearings is interesting in the following cases:
- Within larger assemblies (gears, pumps, wind turbines, machine tools, agricultural machinery, etc.) if the bearing stiffness is not known in advance or there is a clear dependence on the operating point.
- As single bearing simulation for complex or combined load combinations and large or thin bearing rings.
Our specialized FE-bearing models are suitable for all applications. We use them to determine the service life for you under any operating conditions, deformations and stiffnesses, static and dynamic load ratings.
Some examples of products for which the detailed simulation of rolling bearings is suitable:
- Pumps (rotor dynamics, Campbell diagram, resonances)
- Wind power plants (lifetime)
- Transmission (natural frequencies, stiffness, strength)
- Turning and milling spindle (self-frencing, stiffness, service life, heat generation)
Detail simulation of linear guides as a service
Despite its simple design, the highly detail FE simulation of linear guides can provide a high added value. Often the construction of real test benches is too expensive and complex. Analytical design methods, on the other hand, are too general and do not provide insight into the inner life of a linear guide. FE-analysis provides a cost-effective alternative for determining the stiffness or for estimating the service life under any operating conditions.
Measurement of stiffness as a service
The simulation comes very close to reality in the field of static FEA. Nevertheless a comparison with measurements is always desired. With the help of our research partner, the Institute for Machine Tools at the University of Stuttgart, we offer you classic static stiffness measurements quickly and easily on site. Of course we bring the necessary equipment with us.
Experimental modal analysis as a service
The FE-simulation can predict the resonant frequencies of a complex assembly quite well. Regarding the damping, however, deviations of typically 30% can occur if the sources of damping are not sufficiently known. With the help of experimental modal analysis we can determine the damping exactly and adapt the FE-models to reality from the point of view of damping. Usually a single measurement is sufficient to obtain valid data for future developments. The measurements are offered in cooperation with our research partner, the Institute for Machine Tools at the University of Stuttgart.
Experimental frequency response analysis as a service
The frequency response analysis is closely related to the modal analysis. However, the effort required for frequency response analysis is relatively low, because it is limited to a few excitation and measurement points. Nevertheless, this type of analysis can provide important parameters and allow the identification of unknown model parameters. The measurements are offered in cooperation with our research partner, the Institute for Machine Tools at the University of Stuttgart.