All,
I am somewhat of a newbie with Solidworks Simulation. I am running a frequency study on a linear segment of a structural tube member with a fixed top support and 6 simple "immovable" supports on 6 joints of equal spacing. I am trying to validate a study using William F. Stokey, Vibration of Systems Having Distributed Mass and Elasticity, Chapter 7, Table 7.5 Case 3. I have tried modeling the example (rigid with N number of simple supports) with shells and solid bodies with no luck. Using the beam method is the only way I've come across that give reasonable results and accurate results compared to the textbook case. However, I am getting mass participation sums greater than 1 with only a few modes.
Mode No. Freq (Hertz) X direction Y direction Z direction
1 88.865 5.8614e-011 3.9844e-034 0.016617
2 93.58 0.016617 1.0651e-033 5.8614e-011
3 93.58 0.026818 7.5529e-033 2.8911e-010
4 107.04 2.8911e-010 3.1116e-034 0.026818
5 107.04 8.9219e-007 1.4724e-036 0.065241
6 129.83 0.065241 1.1957e-032 8.9219e-007
7 129.83 0.55731 2.2588e-033 5.6867e-008
8 157.39 5.6867e-008 3.9083e-035 0.55731
9 157.39 2.8661e-029 0 3.8163e-030
10 185.07 9.6251e-005 5.724e-034 0.0024821
11 185.07 0.0024821 9.2071e-033 9.6251e-005
12 204.87 0.55731 2.2588e-033 5.6867e-008
13 204.87 5.6867e-008 3.9083e-035 0.55731
14 266.6 2.8661e-029 0 3.8163e-030
15 367.66 9.6251e-005 5.724e-034 0.0024821
16 367.66 0 0 0
Sum X = 1.226 Sum Y = 3.6234e-032 Sum Z = 1.2284
My questions is, what does a mass participation greater than 1 represent. I know some of my modes that have >1% mass participation are probably incorrect by just looking at the mode shape. Any thoughts?
Thank you.
SolidworksSimulation