1.声学超材料的特征为:亚波长条件下的周期性布置振子
2.具体计算公式如下:
Matlab实现
function [F,TL] = MetamaterialPlate(rho,E,h,v,phi,lbx,lby,gamma,nr,fr)%输入板的密度、杨氏模量、板厚、泊松比、声波入射角、胞元尺寸、振子质量比、振子阻尼、振子共振频率
j = 1i;
F=zeros(10000,1);
TL=zeros(10000,1);
%% 空气参数定义
rho0 = 1.2; %空气密度
c0 = 340; %空气声速
%% 平板参数定义
D = E*h^3/(12*(1-v^2)); %板的弯曲刚度
m = rho*h*lbx*lby; %单个胞元面积内板的质量
%% 振子定义
mr = gamma*m; %振子质量
wr = 2*pi*fr; %振子共振角频率
%% 隔声系数计算
for f = 1:1:100000
w = 2*pi*f;
k0 = w/c0;
meq = mr/(1-w^2/(wr^2*(1+j*nr))); %等效动态质量
rhoeff = (m+meq)/(lbx*lby*h); %等效动态质量密度
delta = D*(k0*sin(phi))^4-rhoeff*h*w^2+2*1i*rho0*c0*w/cos(phi);
t = (2*rho0*c0*w/(delta*cos(phi)))^2;
F(f) = f;
TL(f) = 10*log10(1/t);
end
semilogx(F,TL,'k','linewidth',2);
end
3.参数定义如下
MetamaterialPlate(2700,70e9,0.005,0.33,pi/6,0.035,0.035,0.2,0.005,300);