# Rainer_k

Members

5

• Rank
Newbie

## Profile Information

• Are you University user?
Yes

## Recent Profile Visitors

758 profile views

1. ## modelling a beam with large deflection and thermal load

Since there are no replies it may not be so easy? I changed the calculation now in a way that I use the LGDISP 1 Paramter and run it non linear quasi static. This allows for the large deformations. Unfortunately in this kind of calculation there are no 1D elements allowed. I modelled the string with 3D elements but on the result output I want the reaction forces as I draw the bow and this is not implemented yet in the code. I found the Deform parameter though which allowes to apply a strain on 1D elements. So maybe I should go back to non linear geometric calculation with 1D elements but use this artificial shortening instead of the low temperature contraction. I reread the instructions how to use the bulk data entry but I am still not sure how to apply this paramter to the bar elements Does anyone know a tutorial that shows its usage? thanks Rainer
2. ## result output with non linear computation

good evening, I am currently trying to run a computation on a beam section with fairly large displacements. Therefore I run it as a non linear analysis. Because the model uses 1D and 3d elements and temperature and Displacement "loading", the "Geometric non Linear" analysis does not work. Instead I was advised to use the "non linear quasi static" type and set the parameter LGDISP on (1). This will ensure the revision of the stiffness matrix due to the large deflections. With sufficiently small time increments I got a converged solution. However, I would like to output the results for more than just the final time step. Which parameter hast to be set to ensure a result output say every 10 time increments (I had to use 200 in total in order to receive a convergence)? thanks in advance for any help Rainer
3. ## Plot of reaction force makes no sense

hi Prakash, I have tried the output with NLSTAT but to my understanding I will then only receive the result at the end of calculation. At least in the plot I get only a single point as result, not a line Do I really find the results in the .out file? I only get a summation of applied forces and reaction forces an this is ideally zero. regards Rainer
4. ## Plot of reaction force makes no sense

good afternoon, In my model today I have a cantilever beam to which I attach a string. The beam is fixed at one side. The free end of the string is pulled down by applying an SPC with the according nodal displacement. I then try to plot the reaction force at the end of the string vs its displacement and only receive a zigZag line. The calculation is done with a non linear Geometry option because the resultant deflection of the beam is quite large (the material is still elastic yet). I don't know wether it works with the file attachement but I try to attach a screeshot of the result. On the other hand I thouhgt I might as well sum up all the vertical reaction forces at the fixed end of the beam but I couln't find a way to add them all up and plot the sum of the reaction forces vs string displacement. Is there such a function? Would appreciate any help thanks Rainer
5. ## modelling a beam with large deflection and thermal load

good morning, I am fairly new to the Hyper works world and I am struggling on the following topic: A Bow (for Archery) ist modelled in its unstressed geometry (with 3D bricks). The String which is attached to the tip of the bow is in real life shorter than the bow. Hence in reality you bend the bow , attach the string and let it spring back a bit. In the model I attach the string directly to the tip but I try to model it as a beam section with execessive length. In the first load step I wand to shorten (ie. contract ) it by applying a low temperature load. Once the bow has reached its brace hight which is with the string under tension but the arrow basically not pulled back I will then later apply a second load stept where the string is drawn back. I got as far as modelling a beam and a string and run it static but that does not give the large defomation which occur. I activated the NLstat command but that again ist only useful for small deflections. Since the stiffness matrix has to be reassembeld continuously, I activated the NLGeom command. This gives useful results for the bending shape but I seem to have lost the possibility to apply the thermal load because there is no more Temp option any more like it was with static or Quasi static calculation. Has anyone any idea how to progress from here? An alternative to shorten the string by freezing would be maybe by removing elements? Don't know wether this is possible This is only the beginning of a list of topics because there will be the contact issue between string an Bow later on. regards Rainer
×
×
• Create New...