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Dylan Stelzer

Implementation of Tcl in HyperMesh BC's

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Hi,


 


I have another post about this same topic but I wanted to create a new one in order to keep the problem concise and detailed as possible. My goal is that I want to be able to create a constant force load over a curved surface (specifically, the upper half of a semi-circle) and have every force load be normal to said surface while utilizing 2-D shell elements. Currently, this is how I am doing it.


 


1. The geometry (and mesh) is the upper half of a semi-circle with a radius of ~4cm (average element mesh size is 0.05cm).


 


*I have been previously doing this model with only horizontal and vertical forces on the arced surface (never combined)


 


     E.g. Horizontal forces in the +y direction on the left third of the arc, vertical forces in the -z direction on the top third of the arc, and another set of horizontal forces in the -y direction on the right third of the arc.


 


2. My boss asked me to combine horizontal and vertical forces in such a way that I will have a (let's just use an easy number) constant 100N force applied to every node on the arc in a direction normal to the surface of said arc (this is hopefully supposed to simulate some sort of compression-like force load).


 


3. Selecting all of the nodes, I know there are 252 of them on the arc in total.


 


     E.g. This makes sense because the length of the arc is equal to s = pi*radius = 12.5664cm and Total # of Nodes = s/.05cm = 252 nodes (approximately)


 


4. Combining horizontal and vertical forces at each node just requires two simple equations and a little bit of Matlab code


 


*thetaSEP = 180deg / 252 = 0.7143deg (approximately) and hypotenuse = 100N


 


          Iteration 1 (Node 1): cos(thetaSEP) = horizontal/hypotenuse = 100N


                                           -sin(thetaSEP) = vertical/hypotenuse = 0N


 


          Iteration 2 (Node 2): cos(thetaSEP) = horizontal/hypotenuse = 99.9922N


                                           -sin(thetaSEP) = vertical/hypotenuse = -1.2466N


 


          etc. etc. etc. *Horizontal equation changes to -cos AFTER the 126 iteration


 


5. After doing this (and hopefully my math is correct...), I have two vectors, H = [1 x 252] and V = [1 x 252] which have been transferred into Excel (I just like Excel a little better than Matlab) which represents the horizontal and vertical forces that I need to combine at each node to create my constant 100N force load along the arc.


 


***6. Here, I did my first model by hand entering all 252 force vectors, one at a time.


 


               ***This is where I'm hoping someone can give me help on how to automate the process from this point into applying these loads across the nodes I have selected in HyperMesh with correct values (which leads to angle as well).


 


 


 


If anyone has any help or details (or more resources for that matter) that I can try to make this process faster, that would be much appreciated. User: 



Q.NGUYEN-DAI

has already given me some great advice but to be completely honest, I've never used Tcl in my life nor have I really programmed that much.


 Even if someone has a more efficient idea of doing this, could you please explain where I'm making this harder than it needs to be (I understand the "one by one" by hand part is the serious problem)? Thanks ahead of time and sorry for the long post. Attached is an image describing the problem a bit more if you need some visual clues as to further explain my situation.


 


Dylan Stelzer


post-35838-0-12884800-1439474868_thumb.p

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