SolidWorks 2009, Service Pack 2.0
Dell M6300 Workstation Laptop
Windows XP 32bit
2.8 GHz Dual Core (Intel Core2 Extreme)
8 Gb RAM (I have dual boot for 64bit, that's why)
512 Mb NVIDIA Quadro FX 3600M
Does anyone actually use the beam simulation for a mildly complexmodel with any success? I am modeling a spaceframe (vehiclechassis) and can only get the model to successfully (if you cancall it that) run with all joints defined as rigid and all membersdefined as beams (trusses aren't working).
The ideal situation is to model the chassis as steel beams of theirrespective cross-sectional properties and the suspension arms asrigid elements with their joints as hinges (to better simulate howthe loads are fed into and reacted by the chassis - the suspensionmembers are connected through spherical bearings and cannottransmit a moment, only forces). Then apply an enforced 1 degreedisplacement at the front suspension with the rear suspensionfixed. Query the results for reaction forces at the rear SPC's anddetermine torsional stiffness. HOWEVER:
1) There is no option for applying a remote load, rigid link, oranything similar when using beam elements. My original work-aroundwas to define a new "Rigid" material with a really high modulus,however there is a limit on how high you can make the modulus (andit's not as high as I would like it to be)! My second work-aroundwas to model the suspension as solid members of appropriatediameters and model the torsion beam (the component applying thetorsional moment to the chassis) as a 4" diameter beam to minimizeits influence (deflection) on the model.
2) I can model the suspension as rigid if I want to mesh thosecomponents as solid (i.e. treat solid as rigid), but that's justridiculous.
3) Changing joint definitions to hinges does not work, I end upgetting an error saying the stiffness matrix diagonal coefficientis zero at equation 5902. (though my definitions of the hingesshould not cause this). I'm looking to have these joints transmitforces, but no moments to the members they are connected to.
4) Changing above members to truss members rather than beams alsodoes not work, I end up getting some other error that isunexplained (it just says the analysis has failed)
5) When going through the joints and finding ones to delete(members close enough to one another within tolerance to create ajoint there, but not meant to actually have a join there) why can'tyou select the joint from the graphics window? I have to go throughthe list one by one, looking at the graphics until the joint I wantto delete is highlighted. This is no trivial matter when there's170 joints and I want to delete 6 of them!
6) (Somewhat unrelated to the topic, but something worthmentioning) The software doesn't recognize all the structuralmembers in the model! I had to insert a delete bodies feature inthe tree and re-create those members again, then it worked. Not aterrible workaround, but it's not something I should have to do...
7) I've tried deleting the study and starting over, saving as andstarting over, etc. all with no success.
I am lost as to what to do at this point, the only reasonableoption now it to give up on Cosmos and use a proper finite elementprogram (I also use Altair HyperWorks). I'm already well overbudget on this project time-wise, and the transition to the otherprogram certainly won't help that!
It seems quite ridiculous that I am being a beta tester forRELEASED software that is already on Service Pack 2! I don't havethe time to do this when customers are constantly asking when theproject will be done, and it's not an acceptable to answer themwith "This software is just too limited and so buggy that it willtake longer than expected". It's even more ridiculous that I'mpaying in excess of \\\$2000/year for this privilege!
And one more rant: Why does SolidWorks insist on making Cosmos moreuser friendly for the non-engineer/analyst? (I know the answer ispurely to increase sales) It is so bad at this point (SW 2009),that it is harder for the real engineer to actually understand whatis going on - the real engineering is hidden behind so much fluffto make it easier for the non-engineer! This type of analysis isnot for non-engineers, if you don't have enough understanding ofthe theory to be doing the analysis, you shouldn't be doing theanalysis!!! Just because you can get pretty, colorful results plotsdoesn't mean your model (mesh, boundary conditions, assumptions,etc.) is correct and this can have disastrous results...
SolidworksSimulation
Dell M6300 Workstation Laptop
Windows XP 32bit
2.8 GHz Dual Core (Intel Core2 Extreme)
8 Gb RAM (I have dual boot for 64bit, that's why)
512 Mb NVIDIA Quadro FX 3600M
Does anyone actually use the beam simulation for a mildly complexmodel with any success? I am modeling a spaceframe (vehiclechassis) and can only get the model to successfully (if you cancall it that) run with all joints defined as rigid and all membersdefined as beams (trusses aren't working).
The ideal situation is to model the chassis as steel beams of theirrespective cross-sectional properties and the suspension arms asrigid elements with their joints as hinges (to better simulate howthe loads are fed into and reacted by the chassis - the suspensionmembers are connected through spherical bearings and cannottransmit a moment, only forces). Then apply an enforced 1 degreedisplacement at the front suspension with the rear suspensionfixed. Query the results for reaction forces at the rear SPC's anddetermine torsional stiffness. HOWEVER:
1) There is no option for applying a remote load, rigid link, oranything similar when using beam elements. My original work-aroundwas to define a new "Rigid" material with a really high modulus,however there is a limit on how high you can make the modulus (andit's not as high as I would like it to be)! My second work-aroundwas to model the suspension as solid members of appropriatediameters and model the torsion beam (the component applying thetorsional moment to the chassis) as a 4" diameter beam to minimizeits influence (deflection) on the model.
2) I can model the suspension as rigid if I want to mesh thosecomponents as solid (i.e. treat solid as rigid), but that's justridiculous.
3) Changing joint definitions to hinges does not work, I end upgetting an error saying the stiffness matrix diagonal coefficientis zero at equation 5902. (though my definitions of the hingesshould not cause this). I'm looking to have these joints transmitforces, but no moments to the members they are connected to.
4) Changing above members to truss members rather than beams alsodoes not work, I end up getting some other error that isunexplained (it just says the analysis has failed)
5) When going through the joints and finding ones to delete(members close enough to one another within tolerance to create ajoint there, but not meant to actually have a join there) why can'tyou select the joint from the graphics window? I have to go throughthe list one by one, looking at the graphics until the joint I wantto delete is highlighted. This is no trivial matter when there's170 joints and I want to delete 6 of them!
6) (Somewhat unrelated to the topic, but something worthmentioning) The software doesn't recognize all the structuralmembers in the model! I had to insert a delete bodies feature inthe tree and re-create those members again, then it worked. Not aterrible workaround, but it's not something I should have to do...
7) I've tried deleting the study and starting over, saving as andstarting over, etc. all with no success.
I am lost as to what to do at this point, the only reasonableoption now it to give up on Cosmos and use a proper finite elementprogram (I also use Altair HyperWorks). I'm already well overbudget on this project time-wise, and the transition to the otherprogram certainly won't help that!
It seems quite ridiculous that I am being a beta tester forRELEASED software that is already on Service Pack 2! I don't havethe time to do this when customers are constantly asking when theproject will be done, and it's not an acceptable to answer themwith "This software is just too limited and so buggy that it willtake longer than expected". It's even more ridiculous that I'mpaying in excess of \\\$2000/year for this privilege!
And one more rant: Why does SolidWorks insist on making Cosmos moreuser friendly for the non-engineer/analyst? (I know the answer ispurely to increase sales) It is so bad at this point (SW 2009),that it is harder for the real engineer to actually understand whatis going on - the real engineering is hidden behind so much fluffto make it easier for the non-engineer! This type of analysis isnot for non-engineers, if you don't have enough understanding ofthe theory to be doing the analysis, you shouldn't be doing theanalysis!!! Just because you can get pretty, colorful results plotsdoesn't mean your model (mesh, boundary conditions, assumptions,etc.) is correct and this can have disastrous results...
SolidworksSimulation
