Measurements

Experimental conditions
Measurements procedure
Measurement Channels
Experiments
Data Analysis
- Loading of the data
- test

Experimental conditions

Measurement made in the experiment hutch
FS=256Hz
Made by Marc Lesourd on the 12 of October 2018

Date	2018-10-12
Sensors	Geophones
Excitation	Instrumented Hammer
Location	Experimental Hutch

Goal:

The station is now installed on the experimental hutch with a glued granite (final location).
The station is identified again.

Measurements procedure

8 Geophone are used (see table tab:meas_channels):

7 L-28LB geophones (table tab:L-28LB)
1 L-4C geophone (table tab:L-4C)

Natural Frequency [Hz]	4.5
Weight [g]	140
Sensitivity [V/(m/s)]	31.3

L-28LB Geophone characteristics

Natural Frequency [Hz]	1
Weight [g]	2150
Sensitivity [V/(m/s)]	276.8

L-4C Geophone characteristics

The structure is excited using an instrumented hammer with impacts on (see table tab:measurements):

Marble
Ty
Hexapod

Measurement Channels

Les fichiers xxx_raw sont sans traitement dans le domaine temporel (environ 10 impacts par fichier)

Ch. nb	Element	Location	Direction
1	Geophone L-4C	Marble	Z
2	Geophone L-28LB	Ty	Z
3	Geophone L-28LB	Tilt	Z
4	Geophone L-28LB	Hexa	Z
5	Geophone L-28LB	Marble	H
6	Geophone L-28LB	TY	H
7	Geophone L-28LB	Tilt	H
8	Geophone L-28LB	Hexa	H
9	Hammer	Variable	Variable

Description of each measurement channel

Experiments

Meas. nb	Location	Direction
1	Marble	Y
2	Ty	Y
3	Hexa	Y
4	Marble	Z
5	Ty	Z
6	Hexa	Z
7	Marble	X
8	Ty	X
9	Hexa	X

Description of the location of direction of the excitation for each measurement

Data Analysis

Loading of the data

  load('./data/freq_frf.mat');

  load('./data/frf_hexa_x.mat');
  load('./data/frf_hexa_y.mat');
  load('./data/frf_hexa_z.mat');

  load('./data/frf_marble_x.mat');
  load('./data/frf_marble_y.mat');
  load('./data/frf_marble_z.mat');

  load('./data/frf_ty_x.mat');
  load('./data/frf_ty_y.mat');
  load('./data/frf_ty_z.mat');

  load('./data/phs_hexa_x.mat');
  load('./data/phs_hexa_y.mat');
  load('./data/phs_hexa_z.mat');

  load('./data/phs_marble_x.mat');
  load('./data/phs_marble_y.mat');
  load('./data/phs_marble_z.mat');

  load('./data/phs_ty_x.mat');
  load('./data/phs_ty_y.mat');
  load('./data/phs_ty_z.mat');

test

  figure;
  hold on;
  plot(freq_frf, abs(ReIm7(:, 5))./(2*pi*freq_frf), 'DisplayName', 'Marble')
  plot(freq_frf, abs(ReIm8(:, 6))./(2*pi*freq_frf), 'DisplayName', 'Ty')
  % plot(freq_frf, abs(ReIm5(:, 3))./(2*pi*freq_frf), 'DisplayName', 'Tilt')
  plot(freq_frf, abs(ReIm9(:, 8))./(2*pi*freq_frf), 'DisplayName', 'Hexapod')
  hold off;
  xlim([1, 100]);
  set(gca, 'xscale', 'log'); set(gca, 'yscale', 'log');
  legend('location', 'northwest');

  figure;
  hold on;
  plot(freq_frf, abs(ReIm5(:, 1))./(2*pi*freq_frf), 'DisplayName', 'Marble')
  plot(freq_frf, abs(ReIm5(:, 2))./(2*pi*freq_frf), 'DisplayName', 'Ty')
  plot(freq_frf, abs(ReIm5(:, 3))./(2*pi*freq_frf), 'DisplayName', 'Tilt')
  plot(freq_frf, abs(ReIm5(:, 4))./(2*pi*freq_frf), 'DisplayName', 'Hexapod')
  hold off;
  xlim([1, 100]);
  set(gca, 'xscale', 'log'); set(gca, 'yscale', 'log');
  legend('location', 'northwest');

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