Write and solve the loss-factor matrix
Use f = 1000 Hz, η1 = 0.02, η2 = 0.06, η12 = 0.012, η21 = 0.006 and input power P1 = 1 W, P2 = 0 W. The SEA system is ω C E = P.
CA07 exercise · Energy-balance exercise
Assemble and solve a two-subsystem SEA loss-factor matrix, vary damping/coupling parameters and convert subsystem energy into averaged response quantities.
Aim
This exercise treats a plate–cavity-like system with input power into subsystem 1 and energy transfer to subsystem 2. The unknowns are mean subsystem energies, not local pressure/displacement fields.
Use f = 1000 Hz, η1 = 0.02, η2 = 0.06, η12 = 0.012, η21 = 0.006 and input power P1 = 1 W, P2 = 0 W. The SEA system is ω C E = P.
Damping loss factors describe energy dissipation within a subsystem. Coupling loss factors describe energy transfer between subsystems.
What does η12 mainly control?
Python exercise
The code solves the SEA equations over frequency and plots subsystem energies.
Expected observation
The directly excited subsystem stores more energy; the second subsystem receives energy through coupling.
Teaching note
Change η12, η21, η1 and η2 to see the sensitivity of SEA predictions to loss factors.
Written submission
When is SEA appropriate?
State two conditions that make SEA more credible and one situation where SEA is risky.
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