Frequently Asked ?

Q: What is the point of doing this type of analysis?
A: With the widespread use of FEA it is (hopefully) rare to get static failures due to instant overload.
However, it is more likely that failure will occur because of repeated loading over time. Estimates vary, but it is accepted that most engineering failures now occur because of some form of fatigue failure (60% to 80%). By definition, failure will occur at loading well below that to cause static failure. Just because your stresses are, for example, below Yield doesn't necessarily mean that your structure is safe.
Unfortunately Engineers seldom consider fatigue, other than perhaps performing a crude hand calculation.
We wanted to design a tool that could be used as a matter of routine after running a stress analysis and would be easier to perform than a hand calculation.
The problem, up until now, has been that software to do this has been very expensive and cumbersome, almost requiring dedicated "fatigue gurus". Even if you had access to this software the material data provided was generally very poor, or even non-existent!
The fatiguewizard addresses all of these problems with a cost effective, state of the art, easy to use program.

Q: Why is it much cheaper than ******* ?
A: Don't think that because it is cheaper it can't be any good!
We feel that fatigue analysis should be done as a matter of course in most FE simulations, by people who have had little exposure to the subject. The product has therefore been developed and priced to appeal to all.

Q: Is it a limited product?
A: No.

The fatiguewizard performs both stress and strain based analysis as per some of the large (expensive) fatigue codes. Some of the fatiguewizard competitors have far less features and are much more expensive. Try it for yourself.

Q: What about support?
A: Support is via email at support@fatiguewizard.com

Q: What about maintenance?
A: The fatiguewizard ships with 12 months maintenance included. Successive years cost 20% of the retail price at the time of renewal.

Q: What about training?
<>A: The program has been designed to be easy to use and intuitive. If you think you require training then we haven't done our job correctly.
Please tell us which part of the wizard is causing you problems and we will review/improve it.

Q: How accurate is it?
A: The fatiguewizard has been benchmarked against other fatigue codes and gives, essentially, the same results (see our benchmark test results).

Any fatigue analysis result is highly dependent upon the material data entered. This is why the fatiguewizard ships with a large material database which can also be extended by the user.

Q: Do I need to remove the fatiguewizard first if I want to reinstall it?
<>A: Yes - It must be removed via Add/Remove programs under Control Panel

Q: Why does the strain based option take longer to solve than the stress based option?
A: Strain based calculations carry out corrections for material plasticity (using a Neuber correction) and work from a non-linear damage curve. Both of these require an iterative solution which inevitably takes longer than the more straightforward linear interpolation as used in the stress based calculation.

Q: Why does the safety factor calculation option take longer to solve than the cycles to failure option?
A: The safety factor calculation works by an iterative solution. A life calculation is performed using the model stress multiplied by a variable 'safety factor'. The calculated life is compared to the desired life and the 'safety factor' changed accordingly. This process is repeated within an iterative loop until calculated life matches desired life.

Q: I have a 100% beam model and can't see anything in the fatiguewizard post processor. Why?
<>A: Although beams are supported in the fatigue calculations they are not supported in the fatiguewizard post processor. Beam elements can't detect local stresses (stress concentrations) and have little use in detailed fatigue analysis. You should really be using 2D or 3D elements to detect accurate stress concentrations.

Q: I find the fatiguewizard post processor slow to dynamically rotate large models. Why?
A: Dynamically rotating contour plots is one of the most graphically intensive things you can do with a computer. It is far more intensive to do this than to spin a shaded CAD model, for example. This is because each pixel colour that makes up your model needs to be re-calculated in real-time as you rotate the model and each one could be different.
The fatiguewizard postprocessor uses OpenGL for its rendering. This means that you should, ideally, be using an Accelerated OpenGL graphics card. This is not the same as a typical "games" card that uses DirectX as its render engine and emulates OpenGL.
The bottom line is to buy the most powerful OpenGL card you can afford.

Q: Do you offer a consultancy service?
A: Yes. Please feel free to contact us to discuss your requirements.

Q: How does FatigueWizard calculate life for non-proportional loading?
A: More expensive fatigue calculation software provide a multitude of methods for analysing non-proportional loads or 'multiaxial' stress states. Each of these methods will have their own benefits and pitfalls and hence choosing between these methods requires pre-assumed knowledge of fatigue theory. The essence of the FatigueWizard is to provide an  easy to use fatigue tool for general use. To achieve this goal, FatigueWizard utilises an 'equivalent stress' approach, using a signed von mises stress. This should give an acceptable level of accuracy for most situations. In situations, however, where the direction of the principle stress rotates significantly a critical plane calculation may be required.