1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54
|
import("stdfaust.lib");
declare name "StiffString";
declare description "Linear string model with impulse excitation.";
declare author "Riccardo Russo";
//----------------------------------String Settings---------------------------//
//nPoints=int(Length/h);
nPoints = 100;
k = 1/ma.SR;
//Stability condition
coeff = c^2*k^2 + 4*sigma1*k;
h = sqrt((coeff + sqrt((coeff)^2 + 16*k^2*K^2))/2);
T = 150; // Tension [N]
radius = 3.5560e-04; // Radius (0.016 gauge) [m]
rho = 8.05*10^3; // Density [kg/m^3];
Area = ma.PI*radius^2; // Area of string section
I = (ma.PI*radius^4)/ 4; // Moment of Inertia
Emod = 174e4; // Young modulus [Pa]
K = sqrt(Emod*I/rho/Area); // Stiffness parameter
c = sqrt(T/rho/Area); // Wave speed
sigma1 = 0.01; // Frequency dependent damping
sigma0 = 0.0005; // Frequency independent damping
//----------------------------------Equations--------------------------------//
den = 1+sigma0*k;
A = (2*h^4-2*c^2*k^2*h^2-4*sigma1*k*h^2-6*K^2*k^2)/den/h^4;
B = (sigma0*k*h^2-h^2+4*sigma1*k)/den/h^2;
C = (c^2*k^2*h^2+2*sigma1*k*h^2+4*K^2*k^2)/den/h^4;
D = -2*sigma1*k/den/h^2;
E = -K^2*k^2/den/h^4;
midCoeff = E,C,A,C,E;
midCoeffDel = 0,D,B,D,0;
r = 2;
t = 1;
scheme(points) = par(i,points,midCoeff,midCoeffDel);
//----------------------------------Controls---------------------------------//
play = button("Play");
inPoint = hslider("Input Point",floor(nPoints/2),0,nPoints-1,0.01);
outPoint = hslider("Output Point",floor(nPoints/2),0,nPoints-1,0.01):si.smoo;
//----------------------------------Force---------------------------------//
forceModel = play:ba.impulsify;
//----------------------------------Process---------------------------------//
process = forceModel<:fd.linInterp1D(nPoints,inPoint):
fd.model1D(nPoints,r,t,scheme(nPoints)):
fd.linInterp1DOut(nPoints,outPoint)<:_,_;
|