d6a9b3fTwo challenges, each with three strikes at 0, 2 and 4 s; 7 s outputJeremy Magland 2 "challenge_id": "cymbal2-crash-v1",
3 "title": "Bowed, belled and tapered crash cymbal struck three times by a drum stick, on the bell, at half the radius and near the rim: 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": "shell-of-revolution",
19 "mid_surface": "Z(r) = bow_height (1 - r^2/disk_radius^2) + bell_height/2 (1 + cos(pi r / bell_radius)) [r < bell_radius]",
20 "thickness": "h(r) = thickness_center for r <= bell_radius, linear from thickness_center at bell_radius to thickness_rim at disk_radius",
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,
42 "bow_height": 0.025,
43 "bell_radius": 0.055,
44 "bell_height": 0.015,
45 "thickness_center": 0.0012,
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 46 "thickness_rim": 0.00065
f723da2cymbal2: four challenges on one thin-shell cymbal model with a stick strikeJeremy Magland 47 },
d6a9b3fTwo challenges, each with three strikes at 0, 2 and 4 s; 7 s outputJeremy Magland 48 "strikes": [
49 {
50 "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 51 "x": 0.045,
d6a9b3fTwo challenges, each with three strikes at 0, 2 and 4 s; 7 s outputJeremy Magland 52 "y": 0.0
53 },
54 {
55 "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 56 "x": 0.12,
d6a9b3fTwo challenges, each with three strikes at 0, 2 and 4 s; 7 s outputJeremy Magland 57 "y": 0.0
58 },
59 {
60 "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 61 "x": 0.185,
d6a9b3fTwo challenges, each with three strikes at 0, 2 and 4 s; 7 s outputJeremy Magland 62 "y": 0.0
63 }
64 ],
f723da2cymbal2: four challenges on one thin-shell cymbal model with a stick strikeJeremy Magland 65 "metrics": {
66 "primary": "spectrogram_l2",
67 "spectrogram_l2": {
68 "window": "hann_periodic",
69 "n_fft": 2048,
70 "hop": 512
71 },
72 "waveform_l2": {}
73 },
74 "fields": {
75 "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 76 "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 77 "units": "m",
78 "axes": [
79 "t",
80 "y",
81 "x"
82 ],
83 "shape": [
f723da2cymbal2: four challenges on one thin-shell cymbal model with a stick strikeJeremy Magland 85 61,
86 61
87 ],
d6a9b3fTwo challenges, each with three strikes at 0, 2 and 4 s; 7 s outputJeremy Magland 88 "frame_rate_hz": 500,
f723da2cymbal2: four challenges on one thin-shell cymbal model with a stick strikeJeremy Magland 89 "dtype": "float32"
90 },
91 "reference_solution": null
92}