Gallery: strike versions of the sheet and damping sweeps
1 changed file+180−8
docs/gallery/manifest.jsonmodified+180−8View file
@@ -140,7 +140,7 @@
140140 },
141141 {
142142 "id": "bow-amplitude",
143- "title": "Sheet: initial bow",
143+ "title": "Sheet: initial bow (push and release)",
144144 "text": "Real sheet metal has a bow of a few millimetres, which makes it a shallow shell with an asymmetric stiffness. A flat plate has a symmetric, purely hardening nonlinearity; the bowed sheet moves energy out of the inaudible sub-50 Hz range into the audible partials and produces the slow wobble of a real sheet.",
145145 "param": "bowAmplitude",
146146 "unit": "mm",
@@ -152,9 +152,26 @@
152152 0.006
153153 ]
154154 },
155+ {
156+ "id": "bow-amplitude-strike",
157+ "title": "Sheet: initial bow (drumstick strike)",
158+ "text": "The same sweep excited by the default drumstick strike (30 g at 3 m/s) instead of the corner push.",
159+ "param": "bowAmplitude",
160+ "unit": "mm",
161+ "scale": 0.001,
162+ "values": [
163+ 0,
164+ 0.0015,
165+ 0.003,
166+ 0.006
167+ ],
168+ "base": {
169+ "excitation": "strike"
170+ }
171+ },
155172 {
156173 "id": "bow-shape",
157- "title": "Sheet: shape of the bow",
174+ "title": "Sheet: shape of the bow (push and release)",
158175 "text": "The same 3 mm sag as a bow across the width, across the height, or as a dish curved both ways.",
159176 "clips": [
160177 {
@@ -177,9 +194,37 @@
177194 }
178195 ]
179196 },
197+ {
198+ "id": "bow-shape-strike",
199+ "title": "Sheet: shape of the bow (drumstick strike)",
200+ "text": "The same sweep excited by the default drumstick strike (30 g at 3 m/s) instead of the corner push.",
201+ "clips": [
202+ {
203+ "label": "across the width",
204+ "params": {
205+ "bowShape": "width"
206+ }
207+ },
208+ {
209+ "label": "across the height",
210+ "params": {
211+ "bowShape": "height"
212+ }
213+ },
214+ {
215+ "label": "dish",
216+ "params": {
217+ "bowShape": "dish"
218+ }
219+ }
220+ ],
221+ "base": {
222+ "excitation": "strike"
223+ }
224+ },
180225 {
181226 "id": "thickness",
182- "title": "Sheet: thickness",
227+ "title": "Sheet: thickness (push and release)",
183228 "text": "Bending stiffness grows with the cube of the thickness while mass grows linearly, so a thicker sheet has higher mode frequencies, and the same push is a smaller multiple of the thickness, which weakens the nonlinear effects. Gauges 24, 22, 18 and 14.",
184229 "param": "h",
185230 "unit": "mm",
@@ -191,9 +236,26 @@
191236 0.002
192237 ]
193238 },
239+ {
240+ "id": "thickness-strike",
241+ "title": "Sheet: thickness (drumstick strike)",
242+ "text": "The same sweep excited by the default drumstick strike (30 g at 3 m/s) instead of the corner push.",
243+ "param": "h",
244+ "unit": "mm",
245+ "scale": 0.001,
246+ "values": [
247+ 0.0006,
248+ 0.00079,
249+ 0.0012,
250+ 0.002
251+ ],
252+ "base": {
253+ "excitation": "strike"
254+ }
255+ },
194256 {
195257 "id": "size",
196- "title": "Sheet: size",
258+ "title": "Sheet: size (push and release)",
197259 "text": "Plate dimensions (width by height) at the same thickness. Mode frequencies scale with the inverse square of the size, so a larger sheet is lower and slower; it also radiates more efficiently.",
198260 "clips": [
199261 {
@@ -223,9 +285,44 @@
223285 }
224286 ]
225287 },
288+ {
289+ "id": "size-strike",
290+ "title": "Sheet: size (drumstick strike)",
291+ "text": "The same sweep excited by the default drumstick strike (30 g at 3 m/s) instead of the corner push.",
292+ "clips": [
293+ {
294+ "label": "8 x 12 in",
295+ "params": {
296+ "Lx": 0.2032,
297+ "Ly": 0.3048
298+ }
299+ },
300+ {
301+ "label": "12 x 18 in (default)",
302+ "params": {}
303+ },
304+ {
305+ "label": "18 x 24 in",
306+ "params": {
307+ "Lx": 0.4572,
308+ "Ly": 0.6096
309+ }
310+ },
311+ {
312+ "label": "24 x 36 in",
313+ "params": {
314+ "Lx": 0.6096,
315+ "Ly": 0.9144
316+ }
317+ }
318+ ],
319+ "base": {
320+ "excitation": "strike"
321+ }
322+ },
226323 {
227324 "id": "material",
228- "title": "Sheet: material",
325+ "title": "Sheet: material (push and release)",
229326 "text": "Stainless steel, aluminium, and brass at the same thickness. The mode frequencies scale with the square root of E over rho, which differs little between these metals; the loss parameters are kept fixed, although real materials differ there too.",
230327 "clips": [
231328 {
@@ -250,9 +347,39 @@
250347 }
251348 ]
252349 },
350+ {
351+ "id": "material-strike",
352+ "title": "Sheet: material (drumstick strike)",
353+ "text": "The same sweep excited by the default drumstick strike (30 g at 3 m/s) instead of the corner push.",
354+ "clips": [
355+ {
356+ "label": "stainless steel",
357+ "params": {}
358+ },
359+ {
360+ "label": "aluminium",
361+ "params": {
362+ "E": 69000000000.0,
363+ "nu": 0.33,
364+ "rho": 2700
365+ }
366+ },
367+ {
368+ "label": "brass",
369+ "params": {
370+ "E": 100000000000.0,
371+ "nu": 0.34,
372+ "rho": 8500
373+ }
374+ }
375+ ],
376+ "base": {
377+ "excitation": "strike"
378+ }
379+ },
253380 {
254381 "id": "damping-sigma0",
255- "title": "Damping: frequency-independent loss",
382+ "title": "Damping: frequency-independent loss (push and release)",
256383 "text": "sigma0 sets the decay of the lowest modes (T60 = 6.9 / sigma0). It stands in for everything that damps the sheet uniformly: the suspension, air drag, the material.",
257384 "param": "sigma0",
258385 "unit": "1/s",
@@ -262,9 +389,24 @@
262389 3.5
263390 ]
264391 },
392+ {
393+ "id": "damping-sigma0-strike",
394+ "title": "Damping: frequency-independent loss (drumstick strike)",
395+ "text": "The same sweep excited by the default drumstick strike (30 g at 3 m/s) instead of the corner push.",
396+ "param": "sigma0",
397+ "unit": "1/s",
398+ "values": [
399+ 0.4,
400+ 1.15,
401+ 3.5
402+ ],
403+ "base": {
404+ "excitation": "strike"
405+ }
406+ },
265407 {
266408 "id": "damping-sigma1",
267- "title": "Damping: frequency-dependent loss",
409+ "title": "Damping: frequency-dependent loss (push and release)",
268410 "text": "sigma1 makes the high modes decay faster, in proportion to the square of their wavenumber; it stands mainly for radiation into the air. Too little and the highs ring like a cymbal; too much and the sheet sounds dull.",
269411 "param": "sigma1",
270412 "unit": "m^2/s",
@@ -274,9 +416,24 @@
274416 0.0025
275417 ]
276418 },
419+ {
420+ "id": "damping-sigma1-strike",
421+ "title": "Damping: frequency-dependent loss (drumstick strike)",
422+ "text": "The same sweep excited by the default drumstick strike (30 g at 3 m/s) instead of the corner push.",
423+ "param": "sigma1",
424+ "unit": "m^2/s",
425+ "values": [
426+ 0.0001,
427+ 0.0005,
428+ 0.0025
429+ ],
430+ "base": {
431+ "excitation": "strike"
432+ }
433+ },
277434 {
278435 "id": "damping-inplane",
279- "title": "Damping: in-plane loss",
436+ "title": "Damping: in-plane loss (push and release)",
280437 "text": "The stretching modes of the sheet lie at several kilohertz and, once the sheet is curved, couple to transverse motion. Without their own loss they ring for the whole low-frequency decay.",
281438 "param": "sigmaIn",
282439 "unit": "1/s",
@@ -285,6 +442,21 @@
285442 20,
286443 100
287444 ]
445+ },
446+ {
447+ "id": "damping-inplane-strike",
448+ "title": "Damping: in-plane loss (drumstick strike)",
449+ "text": "The same sweep excited by the default drumstick strike (30 g at 3 m/s) instead of the corner push.",
450+ "param": "sigmaIn",
451+ "unit": "1/s",
452+ "values": [
453+ 0,
454+ 20,
455+ 100
456+ ],
457+ "base": {
458+ "excitation": "strike"
459+ }
288460 }
289461 ],
290462 "gainDb": 20