Hi all,
I have been having some trouble on an analysis I am running, let me explain:
I have an assembly whose basic geometry adds up to about 1/3 the total weight of the actual assembly. I have added another 1/3 of weight in point masses which represent the largest components which are inside the assembly. The last 1/3 of the weight is small components, wires, weld material, etc. (things that I do not want to model in as geometry or point masses).
My solution was to add a pattern of point masses along the largest surfaces of the assembly and link them to the rest of the assembly to artificially increase the weight, but still distribute it evenly throughout the system (thus avoiding local stress errors from localized masses).
Without this added blanket mass, my modal response is approx. 100Hz (this is a reasonable value but I need to include the other 1/3 of the total mass). With the blanket mass, the analysis returns values of approx. 1400Hz. This is an unrealistic value which I believe has something to do with how I linked the masses to the surfaces of the assembly (I used rigid links).
So here are my questions:
1. What is the best way to apply rigid links to a pattern of point masses and a surface.
2. Is there a better way to artificially increase the weight of the assembly evenly (I would really prefer to not mess with the densities of the materials I'm using, that will create issues in our system)
Thanks for any feedback,
Matt P.