nass-micro-station-measurements/2018-10-12 - Marc/index.org

#+TITLE: Measurements
:drawer:
#+STARTUP: overview

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#+LATEX_CLASS: cleanreport
#+LaTeX_CLASS_OPTIONS: [tocnp, secbreak, minted]

#+PROPERTY: header-args:matlab  :session *MATLAB*
#+PROPERTY: header-args:matlab+ :comments org
#+PROPERTY: header-args:matlab+ :exports both
#+PROPERTY: header-args:matlab+ :eval no-export
#+PROPERTY: header-args:matlab+ :noweb yes
#+PROPERTY: header-args:matlab+ :mkdirp yes
#+PROPERTY: header-args:matlab+ :output-dir figs
:end:

[[../index.org][Back to main page]].

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

* 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]])

#+NAME: tab:L-28LB
#+CAPTION: L-28LB Geophone characteristics
| Natural Frequency [Hz] |  4.5 |
| Weight [g]             |  140 |
| Sensitivity [V/(m/s)]  | 31.3 |

#+NAME: tab:L-4C
#+CAPTION: L-4C Geophone characteristics
| Natural Frequency [Hz] |     1 |
| Weight [g]             |  2150 |
| Sensitivity [V/(m/s)]  | 276.8 |

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)

#+NAME: tab:meas_channels
#+CAPTION: Description of each measurement channel
| 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  |

* Experiments
#+NAME: tab:measurements
#+CAPTION: Description of the location of direction of the excitation for each measurement
| 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         |

* Data Analysis
** Loading of the data
#+begin_src matlab :exports none :results silent
  <<matlab-init>>
#+end_src

#+BEGIN_SRC matlab :results none :exports none :var currentdir=(file-name-directory buffer-file-name)
  cd(currentdir);
#+END_SRC

#+begin_src matlab :exports code :results none
  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');
#+end_src