2 "challenge_id": "cymbal2-flat-v1",
d6a9b3fTwo challenges, each with three strikes at 0, 2 and 4 s; 7 s outputJeremy Magland 3 "title": "Flat bronze annulus of uniform thickness struck three times by a drum stick: radiated pressure",
f723da2cymbal2: four challenges on one thin-shell cymbal model with a stick strikeJeremy Magland 4 "version": 1,
5 "model": "cymbal2 shallow shell (MODEL.md)",
6 "output": {
7 "type": "wav",
8 "sample_rate_hz": 48000,
d6a9b3fTwo challenges, each with three strikes at 0, 2 and 4 s; 7 s outputJeremy Magland 9 "num_samples": 336000,
f723da2cymbal2: four challenges on one thin-shell cymbal model with a stick strikeJeremy Magland 10 "channels": 1,
11 "sample_format": "float32",
365d2d5Output: Rayleigh integral of the acceleration with its area mean removed (no baffled monopole from the clamped shell's low modes)Jeremy Magland 12 "signal": "acoustic pressure at the listener point from the Rayleigh integral of the transverse acceleration over the shell, with the area mean of the acceleration removed",
f723da2cymbal2: four challenges on one thin-shell cymbal model with a stick strikeJeremy Magland 13 "signal_unit": "Pa",
14 "signal_scale": 16.0,
15 "signal_scale_note": "provisional until the first solutions are published"
16 },
17 "geometry": {
18 "type": "flat",
19 "mid_surface": "Z(r) = 0",
20 "thickness": "h(r) = thickness",
92b7504The stand as a rigid clamp at the mounting radius (20 mm), replacing the hole and the rigid-motion constraintJeremy Magland 21 "domain": "annulus mount_radius <= r <= disk_radius; the inner edge is clamped (the stand), the rim is free"
f723da2cymbal2: four challenges on one thin-shell cymbal model with a stick strikeJeremy Magland 22 },
23 "parameters": {
24 "disk_radius": 0.2032,
92b7504The stand as a rigid clamp at the mounting radius (20 mm), replacing the hole and the rigid-motion constraintJeremy Magland 25 "mount_radius": 0.02,
f723da2cymbal2: four challenges on one thin-shell cymbal model with a stick strikeJeremy Magland 26 "E": 110000000000.0,
27 "nu": 0.34,
28 "rho": 8800.0,
29 "sigma0": 1.1,
d7c7d17Realistic crash: plate-synthesis losses (sigma1 Laplacian term, small eta), firm 6 m/s stroke, rim 0.65 mm, strikes on the bell flank, the bow and the thin edgeJeremy Magland 30 "sigma1": 8e-05,
31 "eta": 1e-09,
f723da2cymbal2: four challenges on one thin-shell cymbal model with a stick strikeJeremy Magland 32 "stick_mass": 0.02,
d7c7d17Realistic crash: plate-synthesis losses (sigma1 Laplacian term, small eta), firm 6 m/s stroke, rim 0.65 mm, strikes on the bell flank, the bow and the thin edgeJeremy Magland 33 "stick_speed": 6.0,
f723da2cymbal2: four challenges on one thin-shell cymbal model with a stick strikeJeremy Magland 34 "contact_stiffness": 1000000000.0,
35 "contact_exponent": 1.5,
36 "strike_radius": 0.005,
37 "rho_air": 1.204,
38 "c_air": 343.0,
39 "listener_x": 0.65,
40 "listener_y": 1.125,
41 "listener_z": 0.75,
d6a9b3fTwo challenges, each with three strikes at 0, 2 and 4 s; 7 s outputJeremy Magland 42 "thickness": 0.001
f723da2cymbal2: four challenges on one thin-shell cymbal model with a stick strikeJeremy Magland 43 },
d6a9b3fTwo challenges, each with three strikes at 0, 2 and 4 s; 7 s outputJeremy Magland 44 "strikes": [
45 {
46 "t": 0.0,
d7c7d17Realistic crash: plate-synthesis losses (sigma1 Laplacian term, small eta), firm 6 m/s stroke, rim 0.65 mm, strikes on the bell flank, the bow and the thin edgeJeremy Magland 47 "x": 0.045,
d6a9b3fTwo challenges, each with three strikes at 0, 2 and 4 s; 7 s outputJeremy Magland 48 "y": 0.0
49 },
50 {
51 "t": 2.0,
d7c7d17Realistic crash: plate-synthesis losses (sigma1 Laplacian term, small eta), firm 6 m/s stroke, rim 0.65 mm, strikes on the bell flank, the bow and the thin edgeJeremy Magland 52 "x": 0.12,
d6a9b3fTwo challenges, each with three strikes at 0, 2 and 4 s; 7 s outputJeremy Magland 53 "y": 0.0
54 },
55 {
56 "t": 4.0,
d7c7d17Realistic crash: plate-synthesis losses (sigma1 Laplacian term, small eta), firm 6 m/s stroke, rim 0.65 mm, strikes on the bell flank, the bow and the thin edgeJeremy Magland 57 "x": 0.185,
d6a9b3fTwo challenges, each with three strikes at 0, 2 and 4 s; 7 s outputJeremy Magland 58 "y": 0.0
59 }
60 ],
f723da2cymbal2: four challenges on one thin-shell cymbal model with a stick strikeJeremy Magland 61 "metrics": {
62 "primary": "spectrogram_l2",
63 "spectrogram_l2": {
64 "window": "hann_periodic",
65 "n_fft": 2048,
66 "hop": 512
67 },
68 "waveform_l2": {}
69 },
70 "fields": {
71 "format": "hdf5",
b9146b9Hold the shell's six rigid motions: the shallow-shell strains are not rotation invariant and a free, tilting shell is unphysicalJeremy Magland 72 "quantity": "transverse displacement w(x, y, t) of the mid-surface; NaN outside the annulus",
f723da2cymbal2: four challenges on one thin-shell cymbal model with a stick strikeJeremy Magland 73 "units": "m",
74 "axes": [
75 "t",
76 "y",
77 "x"
78 ],
79 "shape": [
f723da2cymbal2: four challenges on one thin-shell cymbal model with a stick strikeJeremy Magland 81 61,
82 61
83 ],
d6a9b3fTwo challenges, each with three strikes at 0, 2 and 4 s; 7 s outputJeremy Magland 84 "frame_rate_hz": 500,
f723da2cymbal2: four challenges on one thin-shell cymbal model with a stick strikeJeremy Magland 85 "dtype": "float32"
86 },
87 "reference_solution": null
88}