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Entry  Sat Mar 23 12:52:48 2013, Evan, Notes, PMC, Eigenfrequencies of PMC body: silica and stainless steel pmc_block_sim.jpg
    Reply  Mon Mar 25 16:10:19 2013, Evan, Notes, PMC, Eigenfrequencies of PMC body: silica and stainless steel 
Message ID: 1127     Entry time: Mon Mar 25 16:10:19 2013     In reply to: 1126
Author: Evan 
Type: Notes 
Category: PMC 
Subject: Eigenfrequencies of PMC body: silica and stainless steel 

Quote:

I asked Comsol for the eigenfrequencies of a simplified PMC body. The outer dimensions are as in the design document (6.89″ × 2.375″ × 2.00″), and the borehole has a uniform diameter of 1.188″ (instead of stepping down to a smaller diameter part-way through the body).

Comsol says the lowest mode for silica is at 8.3 kHz, and for stainless steel the lowest mode is at 7.2 kHz. For this simulation the body is assumed to be completely free; I didn't add 3-point contacts or anything like that.

 The lowest longitudinal mode for silica is 16.4 kHz, and for steel is 14.2 kHz.

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