Frequency weighted RMS acceleration.

Hi!

I have time domain data of acceleration for Quarter Car Model.

Can anybody tell me how to find out the Frequency weighted RMS acceleration as per ISO 2631 to calculate Vibration Dose Values (VDV)?

[rash@KL]

For the frequency weighted acceleration, you need to design a filter with high and low pass band limiting filter (butter worth filter can be used). With the weighted acceleration vector now obtained rms and vdv values can be calculated with the following matlab script:

%rms

for i=1:n;

    acceleration(i,1)= acceleration(i,1)^2;
end

y_rms=trapz(t(1:n),acceleration(1:n));

y_rms=(y_rms/t(n))^0.5;

%vdv

for i=1:n

    acceleration(i) = acceleration(i)^4;
end

y_vdv=trapz(t(1:n),acceleration(1:n));

y_vdv=y_vdv^0.25;

%n is the length of the measured acceleration vector

%t is the basic time vector t=(1:1/fs:(n-1)/fs) where fs is the sampling frequency

%acceleration is the measured acceleration vector

%y_rms and y_vdv is the output vector for rms and vdv respectively