It is currently not possible. You can use different SN curves / FAT classes in the hotspot tab, but not in the main window. I have thought of implementing something like that, but it won’t be done any time soon:)

BR Mikkel

]]>Congratulations for your great tool.

I’ve a question for you; there is the possibility to use different FAT curves for different parts of a model?

if not, will be a future update?

Best regards

R. Luca ]]>

got it! I don’t know if it makes sense to post all the changes in a comment. What I did was to add an extra option “3D Interpolation” in the setup model window. If activated, Fatlab changes the next two entries to Var1/Var2 (similar to the 2D interpolation idea). In “calc_stress_nonlinear.m” I added an extra array “ULC_stress_3D” with the shape (max_ULC_per_load,max_ULC_per_load,max_ULC_per_load). In the beginning I made a mistake with the order of F,V,W in interp3: Matlab requests the order V,F,W. Here and there I made some extra changes regarding error treatment, but basically that’s it. I went through the whole code with the matlab search function for all files with “2D interpolation” and added extra options for the 3D one. If you are interested in specific code changes, I think it’s better if you contact me per mail. I’ve also added some other features (more elastomer / rubber specific ones) so sending my modified files is probably not the best idea as there are too many changes in it. I will sort the interpolation code changes out if there is any interest.

BR Andreas

]]>BR Mikkel

]]>thank you for your response! Well, I looked through the examples and found out that it is possible to do a linear combination (superposition) of the stress states. Like having Fx and all the stress files, Fy and all the stress files and Fz and all the stress files. Fatlab is then searching for a combined stress state of the actual loading situation Fx(t), Fy(t) and Fz(t) given in the load-time history. Thats already a great feature! Also it is possible to have a 2D interpolation for example Fx with a dependency of Fy. So, what I’m looking for is an interpolation feature for Fx(Fy,Fz): one load and two variables.

My problem is, due to all the nonlinearities in my model, the stress state depends on the spatial loading situation. For example, if a have 3 external displacements, my stress state a) sx(sy,sz=0) is different than stress state b) sx(sy,sz=2).

I tried to extend the 2D interpolation feature to 3D with two dependent variables but my attempt was not successful so far. If I have success I’ll let you know.

BG Andreas

]]>Certainly. Fatlab can handle as many load signals as you like. You just make more columns in the loads file. Several of the examples include multiple loads. Also, you can use different scaling/interpolation techniques for the different loads. E.g. one load can scale the FE stresses linearly, whereas another may be interpolating.

BR Mikkel

]]>is Fatlab capable of dealing with 3 dimensional input signals (for example 3 time series like Fx(t), Fy(t), Fz(t))? I think it should work somehow within the Load(Variable) concept using Load(Var1,Var2).

BR,

Andreas

Best regards,

Andreas

Thanks for posting. I will not be porting the program any time soon. I don’t have the time, nor the skills with other programming languages. But anyone looking for a challenge should be much welcome and I will gladly support the effort.

BR Mikkel

]]>Thank you for providing this fatigue calculation resource.

I very much appreciate the open source nature of your project; would you consider developing a version that doesn’t require MatLab? I’m thinking of the possibility of using Octave instead of MatLab; I imagine that the calculation aspect would be less of a concern than the GUI creation.

Kind regards,

Tim Gowing ]]>