Pro Mechanica: Load Transfer between Comp

[Scorpio84]

Dear all,



The model I am trying to analyse is a statically indeterminate structure. I am trying to perform a static analysis on the structure. The structure consists of simple rectangular bars connected via pin / bracket joints. I want to apply a load to the end of one bar and analyse the loading / stress levels that result from this input load in the other connected components of the assembly.



When I run an analysis the input load remains localised in the component it is being applied to. The load does not transfer to the neighbouring component, nor does it transfer through the pin / bracket joints joining the components together.



My question is this; In simplified terms, if I connect a 30mm x 700mm rectangular steel bar to a 30mm x 100mm rectangular steel bar at right angles for example using a simple pin / bracket joint and apply a load to the 30mm x 100mm rectangular steel bar, while constraining the 30mm x 700mm rectangular steel bar, how do I get the load to transfer from the smaller bar through the pin and bracket joint into the larger bar?



I have defined the interfaces between the bars, the pin and the bracket. I have used the "fastener bolt" tool to secure the pin and I have also applied a "pin constraint" to the pin. I have defined the interface surfaces using the connection tools in Pro Mechanica and I have applied "infinite friction" between components to prevent "insufficient constraint". I have used shells to try and link the elements of one component to the next, in an effort to get the software to transfer the load from one component to the next.



When I run this type of simulation, the load will remain localised in the 30mm x 100mm bar causing it to deflect. The simulation shows no sign that the components of this simple assembly are connected in anyway.



Can anyone see anything obvious that I might be doing wrong? Is there a way to define the component interfaces so that the load from one bar transfers through the bolt / bracket joint into the other connected rectangular bar? The problem that I am working on is a more complicated assembly, but the main problem I encounter is getting the load to transfer throughout the entire assembly instead of remaining localised in the component the load is being applied to.



Any advice or insight into this problem would be greatly appreciated.



Thank you very much.

 

[mgage2000]

In your analysis study, did you check the "nonlinear" box? This opens up so that you can check the "include contacts" box. Hopefully thats all you need to do.


Marcus

 

[Scorpio84]

Marcus,


Thank you very much for your reply. I think you managed to pin-point the problem I was having. You wouldn't believe the hours I spent trying to define interfaces etc to getthe load to distribute properly.


Thank you very much for your help. I greatly appreciate it. You have caused my stress levels to drop significantly...


Thanks again and bravo...

Owen

 

[alwaysdrunk]

hi owen


you can also use " use in structure" in mechanism dynamics if you need to analyze via mechanicathe member after the pin connection. using mechanism dynamics, you can apply force motor to your 30x100 steel bar for it to rotate via pin connection. use " use in structure" in edit menu to get the loads carried by the 30x700 steel and open it up with mechanica. you will notice the reaction forces and moments given off by the pin connection, you can choose among those forces which to include in the mechanica analysis and simply place them in their proper surface of application. I suggest to read the help file within proe to leran more.


hope that healps

 

[mgage2000]

Owen,


You're very welcome. I recognized your problem because I had the exact same thing happen to me about a month ago. I spent a whole day just trying to get simple two part assemblies to work before I discovered the problem. I'm glad I was able to cut down your stress level...


Marcus