CA07 exercise · Energy-balance exercise

Two-Subsystem SEA Model

Assemble and solve a two-subsystem SEA loss-factor matrix, vary damping/coupling parameters and convert subsystem energy into averaged response quantities.

45–75 minLinked to Statistical Energy AnalysisDashboard progress enabled

Aim

Solve a two-subsystem SEA balance

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.

1

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.

2

Interpret the parameters

Damping loss factors describe energy dissipation within a subsystem. Coupling loss factors describe energy transfer between subsystems.

What does η12 mainly control?

Python exercise

Run the two-subsystem SEA model

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

Validity of SEA

When is SEA appropriate?

State two conditions that make SEA more credible and one situation where SEA is risky.

0 words
Saved automatically in this browser draft.

Submit solution

Classroom submission workflow

When a student is logged in, the submission is stored in Supabase and becomes visible to the supervisor grading page across devices. Local browser storage remains as fallback.

Supabase not configured

Checking login...

Draft status

0%

0 checks · 0 answers · 0 runs

Student identity

Enter temporary identity until login is active.