1function P = plate_setup(params)
2% PLATE_SETUP Constants derived from the parameters, shared by both methods.
3%
4% P = plate_setup(params) copies params and adds
5% D bending rigidity E h^3 / (12 (1 - nu^2)) [N m]
6% hole_area area of the suspension hole [m^2]
7% hole_x, hole_y the hole, on the centreline near the top edge [m]
8% plate_mass rho h (W H - hole area) [kg]
9% g standard gravity [m/s^2]
10% thread_k transverse spring of the thread at the hole,
11% m g / L: the linearized pendulum, not a clamp [N/m]
12% critical_frequency coincidence frequency c^2 / (2 pi) sqrt(rho h / D),
13% below which a small unbaffled plate radiates
14% inefficiently [Hz]
15% f_max highest mode kept, 0.47 fs [Hz]
16% Kb, Ks surface-stress factors E h / (2 (1 - nu^2)) and
17% E h / (2 (1 + nu)) (plate_stress) [Pa m]
18% hertz the contact constants (plate_hertz)
19%
20% Coordinates are measured from the plate's centre, x to the right and
21% y towards the threaded top edge, as in the simulators this lab follows.
23P = params;
24pl = params.plate;
25mat = params.material;
26P.D = mat.E * pl.thickness^3 / (12 * (1 - mat.nu^2));
27P.hole_area = pi * (params.hole.diameter / 2)^2;
28P.hole_x = 0;
29P.hole_y = pl.height / 2 - params.hole.edge_offset;
30P.plate_mass = mat.rho * pl.thickness * (pl.width * pl.height - P.hole_area);
31P.g = 9.80665;
32P.thread_k = P.plate_mass * P.g / params.thread.length;
33P.critical_frequency = params.mic.sound_speed^2 / (2 * pi) * sqrt(mat.rho * pl.thickness / P.D);
34P.f_max = 0.47 * params.render.fs;
35P.Kb = mat.E * pl.thickness / (2 * (1 - mat.nu^2));
36P.Ks = mat.E * pl.thickness / (2 * (1 + mat.nu));
37P.hertz = plate_hertz(params);
38end