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Data från byggakustiska fältmätningar och enkätundersökningar i flerfamiljshus. AkuLite Rapport 8 : Bilaga. Mätrapport 5 Hyttkammaren

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Measurement  Report    

Kv.  Hyttkammaren,  Falun  

21-­2-­2012  

                                   

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In-­‐situ   acoustic-­‐vibratory   measurements   were   performed   at   a   lightweight   5-­‐storey-­‐building  “kopparhatten”  in  Falun  (Sweden).  The  building  can  be  seen  in   Figures   1   and   2.   Two   apartments   were   at   our   disposal   to   carry   out   the  

measurements.  Both  of  them  were  placed  on  top  of  each  other  (2nd  and  3rd  floor  of  

the   building),   allowing   measurements   between   adjacent   spaces.   By   these   measurements,  it  is  planned  to  acquire  an  insight  of  the  building  in  terms  of  sound   insulation,   impact   sound   insulation,   as   well   as   different   aspects   regarding   its   vibratory  performance.  

 

   

Figure  1.  Front  facing  façade.    

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1.1.-­‐  Limiting  factors    

It  should  be  mentioned  that  there  were  some  factors,  which  may  affect  the  results   of  these  measurements.  The  main  issue  was  that  people  were  living  at  the  building   at  the  time  when  the  measurements  were  carried  out  (and  moreover,  at  home  in   that   precise   moment   doing   daily   activities).   For   obvious   reasons,   that   fact   made   the   measurements   more   complicated   when   carrying   them   out,   as   not   as   much   noise   as   needed/desired   was   possible   to   make.   The   measurements   could   have   been  influenced  by  those  activities  and  thus  the  results  should  be  questioned  and   analysed  cautiously.  

 

Moreover,   the   force   transducer   of   the   instrumented   hammer   available   did   not   work   properly   thus   not   being   able   to   display   and   record   its   force.   Due   to   this,   springiness  and  mobility  measurements  were  not  carried  out.  

   

2.-­  The  construction    

All  construction  details  of  investigated  object  were  not  available  to  us.  Therefore   details  on  the  dimensions  of  beams  and  such  are  omitted.  However,  the  building  is   comprised   of   a   wooden   frame   and   façade.   The   ceiling   height   is   2.40m   and   the   flooring  is  parquet  throughout  the  apartment  with  the  exception  of  the  bathroom.   A   detail   of   the   floor   construction   and   apartment   separating   walls   can   be   seen   in   Figure  3.    

   

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2.1.-­‐  Rooms  used  for  the  measurements    

The  limited  amount  of  time  we  had  to  carry  out  the  measurements  (9  am  -­‐16  am)   forced  us  to  just  be  able  to  measure  in  a  total  number  of  4  rooms  (two  rooms  in   each  apartment),  which  can  be  described  as  follows:  

 

-­‐  Apartment  3rd  floor:  

    -­‐Living  room  (hereafter  denoted  LivRoom3):      

Volume:  5.05  x  4  x  2.5  m  

-­‐Room  next  to  the  living  room  (hereafter  denoted  Room3)   Volume:  3.2  x  4  x  2.5  m  

 

-­‐  Apartment  2nd  floor:  

    -­‐Living  room  (hereafter  denoted  LivRoom2  –right  below  LivRoom3-­):      

Volume:  5.05  x  4  x  2.5  m  

-­‐Room  next  to  the  living  room  (hereafter  denoted  Room2)   Volume:  3.2  x  4  x  2.5  m  

   

The  layout  of  the  apartments  can  be  seen  in  Figure  4.    The  vibratory  measurements   have  been  performed  in  LivRoom2  and  LivRoom3  as  indicated  in  the  drawing,  the   walls  used  for  the  measurements  are  indicated  in  red.  

   

   

Figure  4.  Floor  plan.  Apartment  layout  indicated  in  blue.  

  LivRoom Room Wall Outer Wa ll In n e r

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The  equipment  used  for  the  measurements  is  described  below:    

• MEMS  accelerometers  (Analog  Devices):  

 ADXL  203  

 ADXL  202E  

• 32-­‐channel  synchronous  data  acquisition  system  

 Acquisition  software  Spectrum  SBench  6.1  

• ISO  B&K  tapping  machine  

• Loudspeaker    

• B&K  instrumented  hammer  

• Standarized  Japanese  Ball  

• Amplifiers     • Sonometer  Norsonic®  140       4.-­  Measurements    

First   of   all,   some   preliminary   notes   should   be   pointed   out   regarding   the   room-­‐ acoustic   measurements.   Along   this   report,   it   will   be   referred   to   different   measurement   positions   when   recording   with   the   sound   level   meter.   Those   spots   were   chosen   trying   to   find   a   compromise   between   the   location   (spread   enough)   and  accessibility  (due  to  existent  furniture).  They  were  roughly  located  as  shown   in  Figure  5.  

   

  Figure  5-­‐  Measurement  positions  with  the  sound  level  meter  in  (a)  LivRoom2  and  LivRoom3;  and  

(b)  Room2  and  Room3      

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4.1.-­  Airborne  sound  insulation    

The   objective   of   the   following   is   to   measure   the   airborne   sound   insulation   following  the  current  standards  (ISO  140-­‐7,  ISO  717-­‐2  and  SS  25267),  within  the   frequency   range   going   from   50   Hz   to   5000   Hz.   Thus,   the   parameters   to   be   extracted  are  R’  in  third  octave  bands  (50-­‐5000  Hz),  R’n,w,  Cl,50-­‐2500  and  Cl,50-­‐5000.  

Please   note   that   the   procedure   described   in   the   standards   was   not   properly   followed   due   to   the   occupancy   of   the   building   and   for   instance,   only   5   seconds   recordings  with  the  loudspeaker  were  done.  

 

First   of   all,   the   reverberation   time   of   LivRoom2   and   Room3   was   calculated   by   emitting  a  noise  with  the  loudspeaker  during  15  seconds  and  recording  with  the  

Norsonic  at  the  five  positions  previously  explained.  

The   reverberation   time   will   allow   us   to   calculate   the   effective   absorption   area,  

A[m2],  of  the  receiving  room  according  to  (V[m3]  volume  of  the  room):  

 

𝑅𝑇 = 0.16   𝑉

𝐴    

The  equivalent  sound  pressure  levels  in  the  other  rooms  of  interest  (Room3  and   LivRoom2)  were  measured  when  exciting  with  the  loudspeaker,  which  was  placed   at  the  middle  of  the  floor  of  LivRoom3.  Hence,  our  sending  room  was  LivRoom3  and   the  receiving  rooms  all  the  others.    

 

Thus,  R’  [dB]  is  calculated  as:    

𝑅! 𝑑𝐵 = 𝐿

!"#$%#&− 𝐿!"#"$%$&'+ 10log  

𝑆 𝐴    

being   Lsending   and   Lreceiving   the   sound   pressure   level   in   the   sending   and   receiving  

room  respectively  (in  decibels),  A[m2]  the  effective  absorption  area  and  S[m2]  the  

surface  of  the  partition  to  be  studied.    

The  summary  of  the  measurements  done  is:    

 

Sending  Room   Receiving  Room   R'w   Cl,50-­‐3150   R'w+Cl50-­‐3150   Soundclass   Apt.   Floor   Room   Apt.   Floor   Room  

3001   3   LivRoom3   2001   2   LivRoom2   56   -­‐3   53   C   3001   3   LivRoom3   3001   3   Room3   55   -­‐2   53   C  

   

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4.1.1.-­‐  Sound  insulation  between  LivRoom3  and  LivRoom2    

The  results  obtained  for  the  floor  partition  between  LivRoom3  and  LivRoom2  are:    

   

   

NOTE:    VolReceiving  Room=  50.05  m3  

Apartition=20.2  m2     Results   R’w=56  dB   C50-­‐5000=-­‐2dB   C50-­‐3150=-­‐3  dB          

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4.1.1.-­‐  Sound  insulation  between  LivRoom3  and  Room3    

The  results  obtained  for  the  wall  partition  between  LivRoom3  and  Room3  are:    

   

 

NOTE:    VolReceiving  Room=  32  m3  

Apartition=10  m2   Results   R’w=55  dB   C50-­‐5000=-­‐1dB   C50-­‐3150=-­‐2  dB                        

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4.2.-­  Impact  sound  insulation    

The  objective  is  to  measure  the  structure-­‐borne  sound  insulation  following  the  current   standards  (ISO  140-­‐7,  ISO  717-­‐2  and  SS  25267)  within  the  frequency  range  50  Hz  -­‐  5000   Hz.   In   order   to   calculate   the   impact   sound   insulation   index   the   tapping   machine   was  

placed  at  the  middle  of  the  floor  in  LivRoom3  and  recordings  with  the  Norsonic    in  third  

octave  bands  were  performed  in  LivRoom2  and  Room3.  The  same  five  different  positions   were   considered   when   recording.   As   a   result   of   this   analysis,   L’   in   third   octave   bands   (50-­‐5000  Hz),  L’nw,  and  C50-­‐3150    should  be  obtained.  

 

As   the   volume   of   all   receiving   rooms   (LivRoom2  and  Room3)   is   larger   than   31  m3,   the  

following  correction  must  be  done  according  to  ISO  140-­‐7:    

𝐿!"## = 𝐿!− 10 log

𝑇

𝑇! [𝑑𝐵]  

 

being   Lr   the   sound   pressure   level   in   the   receiving   room,   T   the   reverberation   time   for  

each  frequency  and  T0=0.5  s.  

 

Hence,  L’  [dB]  is  calculated  as  follows:     𝐿! 𝑑𝐵 = 𝐿 !"#"$%$&'+ 10log   𝐴 10      

being  Lreceiving  the  sound  pressure  level  in  the  receiving  room  (in  decibels)  and  A[m2]  the  

equivalent  absorption  area,  calculated  from  the  reverberation  time.    

 

The  summary  of  the  measurements  done  is:    

 

Sending  Room   Receiving  Room   L'n,w   Cl,50-­‐2500   L'n,w+Cl50-­‐2500   Soundclass   Apt.   Floor   Room   Apt.   Floor   Room  

3001   3   LivRoom3   2001   2   LivRoom2   54   5   59   D   3001   3   LivRoom3   3001   3   Room3   60   0   60   D  

   

Plots  with  the  results  are  presented  next:    

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4.2.1.-­‐  Impact  sound  insulation  between  LivRoom3  and  LivRoom2    

The  results  obtained  for  the  floor  partition  between  LivRoom3  and  LivRoom2  regarding   impact  sound  insulation  are:  

   

   

 

NOTE:    VolReceiving  Room=  31  (50.05)  m3  

  Results   L’nw=54  dB   C50-­‐2500=5  dB                          

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4.2.2.-­‐  Impact  sound  insulation  between  LivRoom3  and  Room3  

 

The   results   obtained   for   the   wall   partition   between   LivRoom3   and   Room3   regarding   impact  sound  insulation  are:  

   

   

NOTE:    VolReceiving  Room=  31  (32)  m3  

  Results   L’nw=60  dB   C50-­‐2500=0  dB                  

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4.3.-­  Sound  from  the  Japanese  ball  

 

The   sound   produced   and   transmitted   when   dropping   the   Japanese   ball   from   1  meter   height   on   the   middle   of   the   floor   of   LivRoom3   (sending   room)   was   measured   in   all   receiving   rooms   (Room3,   LivRoom2   and   Room2)   in   the   frequency   range   20  Hz-­‐500   Hz   (time  constant:  fast  125  ms).  In  the  following  table,  the  values  of  the  maximum  sound   pressure  levels  are  presented  for  the  sending  room  (LivRoom3)  and  the  receiving  rooms.    

Table  1.  Total  Lmax  [dB]  in  all  rooms.  

 

 

Floors Room Lmax (centre) [dB] Lmax (centre) [dBA] Lmax (corner) [dB] Lmax (corner) [dBA]

3 LivRoom 3 102,7 64 98,6 60.3 3 Room3 90,5 50.4 91,1 51.1 2 LivRoom2 93,8 53.8 93,8 54.3 2 Room2 88,4 47.3 89,7 51.6    

4.4.-­  Vibrations  from  the  Japanese  ball  (only  possible  for  LivRoom3)  

 

The  vibrations  produced  by  the  Japanese  ball  in  the  frequency  range  from  1  Hz  to   500  Hz  are  to  be  measured.  It  was  dropped  from  1  meter  high  and  it  bounced  until   it  came  to  a  complete  rest.  Meanwhile,  the  response  of  the  floor  was  measured  as  

shown  in  Figure  6.  The  parameters  of  interest  are  the  maximum  acceleration  (amax)  

and  also  the  lowest  eigenfrequency  as  well  as  plot  “acceleration  versus  time”.    

  Figure  6  –  Layout  of  accelerometers  and  excitation  point  

     

Table  2.  Maximum  RMS  acceleration  created  by  the  Japanese  ball   Room   Amax  acc5  m/s2  rms   Amax  acc6  m/s2  rms  

LivRoom3   3,53   3,03     0.5m Acc6 Acc5 Excitation Response 0.5m

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f  (Hz)   10   16   20   25   31,5   40   50   63   80   Acc  5   0,173   0,170   0,159   0,194   0,157   0,089   0,084   0,126   0,176   Acc  6   0,208   0,061   0,129   0,325   0,197   0,061   0,127   0,100   0,164   f  (Hz)   100   125   160   200   250   315   400   500     Acc  5   0,089   0,174   0,387   0,156   0,090   0,062   0,047   0,042     Acc  6   0,209   0,185   0,154   0,084   0,068   0,091   0,092   0,035        

In  Figures  7,  8  and  9  a  detail  of  the  impulse  from  the  ball  is  presented.  The  first   eigenfrequency  can  be  clearly  identified  at  about  14Hz.  

 

 

  Figure  7  –  Impulse  from  the  Japanese  Ball  measured  by  Acc5  

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  Figure  9  -­‐  Impulse  in  the  frequency  domain  from  the  Japanese  Ball  measured  by  Acc6    

   

4.5.-­  Flanking  transmission  (between  LivRoom3  and  LivRoom2)  

 

The   objective   is   to   measure   how   the   vibrations   travel   through   a   junction   in   the   frequency   range   1   Hz-­‐500   Hz   (when   exciting   with   the   Japanese   ball)   and   10-­‐ 3150  Hz  (when  having  the  tapping  machine  as  excitation  source)  

 

The   excitation   was   on   the   middle   of   LivRoom3  when   dropping   the   Japanese   ball   from  1  m  height  and  the  tapping  machine  measuring  with  the  accelerometer  setup   shown  in  Figures  10-­‐11.  Note  that  the  accelerometers  placed  on  the  walls  (acc10-­‐ 14  and  acc25-­‐29)  are  in  a  vertical  line  and  not  in  the  horizontal.  The  walls  used  for   the  measurements  are  indicated  in  Figure  4.  

   

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Figure  11  –  Accelerometers  distribution,  left  upper  (sending)  room,  right  lower  (receiving)  room.    

 

The  same  measurement  was  performed  three  times  (for  the  tapping  machine)  and   five  times  (for  the  Japanese  ball)  in  order  to  have  a  good  repeatability.    

 

The   Flanking   transmissions   in   both   narrow   band   and   third   octave   band   for   all   measurement  cases  in  Figures  12-­‐19.  In  tables  4  and  5  the  mean  acceleration  for   the   different   measurement   groups   are   shown,   in   third   octave   band   and   in  

maximum  acceleration  (Amax).  

      Acc1 Acc14 Acc13 Acc12 Acc11 Acc10 Acc9 Acc8 Acc7 Acc6

Acc5 Acc4 Acc3 Acc2

FLOOR

Acc21 Acc20

Acc19 Acc18 Acc17 Acc16 Acc15

Acc25 Acc23 Acc24 Acc26 Acc27 Acc29 Acc28 CEILING WALL WALL Acc1 Acc12 Acc11 Acc10 Acc9 Acc8 Acc7 Acc6

Acc5 Acc4 Acc3 Acc2

FLOOR

Acc21 Acc20

Acc19 Acc18 Acc17 Acc16 Acc15

Acc25 Acc23 Acc24 Acc26 Acc27 Acc29 Acc28 CEILING WALL WALL

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  Figure  13  -­‐  Mean  of  vibrations  over  flank  using  tapping  machine  (measured  along  an  internal  wall)  

one  third  octave  band.    

 

 

Figure  14  -­‐  Mean  of  vibrations  over  flank  using  Japanese  Ball  (measured  along  an  internal  wall)   narrow  band.  

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Figure  15  -­‐  Mean  of  vibrations  over  flank  using  Japanese  Ball  (measured  along  an  internal  wall)  one   third  band  

   

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Figure  17  -­‐  Mean  of  vibrations  over  flank  using  Tapping  Machine  (measured  along  an  outer  wall)   one  third  band  

 

 Figure  18  -­‐  Mean  of  vibrations  over  flank  using  Japanese  Ball  (measured  along  an  outer  wall)   narrow  band.  

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  Figure  19  -­‐  Mean  of  vibrations  over  flank  using  Japanese  Ball  (measured  along  an  outer  wall)  one  

third  band.    

Table  4.  Frequency  content  of  accelerations  for  the  mean  of  the  different  accelerometers  (mm/s^2   rms.  excitation:  Japanese  ball)  in  Third  Octave  bands.  

Frequency   (Hz)   (mm/sWall  Up  2)   Floor  Inner   (mm/s2)   Floor  Outer   (mm/s2)   Wall  Down   (mm/s2)   Ceiling  Inner   (mm/s2)   Ceiling  Outer   (mm/s2)   10   3,68   42,75   56,26   11,09   21,87   11,94   16   6,40   47,79   71,42   7,68   20,87   21,96   20   13,45   46,03   47,29   11,96   35,28   44,85   25   29,28   77,74   80,95   17,12   26,50   36,99   32   13,80   48,62   50,73   6,57   16,44   13,63   40   11,68   41,68   31,03   3,31   8,05   12,39   50   5,28   33,83   12,46   4,70   7,79   5,49   63   8,03   49,96   51,56   4,40   9,28   10,80   80   5,10   44,93   32,35   4,01   13,10   9,09   100   9,23   49,18   45,65   7,21   14,10   20,82   125   13,33   36,44   49,18   5,59   11,10   15,31   160   12,80   26,12   85,45   3,47   9,75   14,69   200   5,08   13,85   48,87   3,07   3,21   3,38   250   2,64   13,49   24,21   2,09   1,97   2,05   315   2,92   6,75   9,45   1,91   1,97   1,77   400   2,40   3,47   4,81   2,03   1,70   1,76   500   2,11   2,52   3,58   2,01   1,71   1,61   630   1,92   2,32   2,54   1,76   1,69   1,69   800   1,82   2,25   3,49   1,85   1,76   1,66   1000   1,78   1,94   3,22   1,78   1,55   1,51   1250   1,68   1,81   2,72   1,68   1,53   1,40   1600   1,62   1,73   1,88   1,49   1,33   1,37  

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4.6.-­  Surface  Vibration  of  the  Floor  (LivRoom3)  

 

The   objective   is   to   measure   and   analyse   how   the   vibrations   travel   through   the   floor   and   how   they   are   dampened   from   the   source.   The   frequency   ranges   of   interest  are  1-­‐500  Hz  when  exciting  with  the  Japanese  ball  and  20-­‐3150  Hz  when   exciting  with  the  hammer  machine.  

 

The   excitation   was   at   the   middle   of   LivRoom3   when   dropping   the   Japanese   ball   from  1  m  height  and  the  tapping  machine.  The  accelerometers’  setup  is  shown  in   Figure  20.  In  Figures  21-­‐24  the  resulting  surface  vibrations  in  the  two  directions   are  shown  bot  in  narrow  band  and  in  third  octave  band.  The  acceleration  from  the   Japanese  ball  is  shown  in  third  octave  bands  in  table  6  and  in  table  7  the  maximum   acceleration  is  shown.  

    Figure  20  –  Layout           0.5m Acc6 Acc5 Excitation Response Acc1 Acc3 Acc4 Acc2 0.32m 0.5m 0.5m 0.375m 0.5m Acc7 Acc8 Acc9 Acc10

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  Figure  22  -­‐  Floor  vibrations  from  tapping  machine  narrow  band  

   

  Figure  23  -­‐  Floor  vibrations  from  tapping  machine  one  third  octave  band  

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  Figure  24  -­‐  Floor  vibrations  from  tapping  machine  one  third  octave  band.  

   

Table  6.  Frequency  content  in  accelerations  for  the  different  accelerometers  (mm/s^2  rms.   excitation:  Japanese  ball)  in  Third  Octave  bands.  

Pos   Freq  

 

Acc1   Acc2   Acc3   Acc4   Acc5   Acc6   Acc7   Acc8   Acc9   Acc10   10,00   13,53   51,65   92,66   138,94   172,71   207,90   165,54   144,90   124,65   66,14   16,00   45,15   119,91   165,23   175,61   170,12   61,37   70,93   81,48   65,16   36,97   20,00   77,51   194,70   253,86   234,11   159,43   129,02   187,84   189,98   160,56   81,85   25,00   109,77   221,27   240,61   157,84   193,94   325,14   368,92   355,11   316,07   141,92   31,50   52,90   99,59   104,68   97,18   156,93   196,73   234,06   231,89   217,17   102,14   40,00   33,76   76,08   77,02   42,69   89,21   60,99   139,39   184,27   202,96   102,78   50,00   13,58   29,38   30,76   40,10   83,84   126,66   97,67   101,74   141,72   76,92   63,00   31,01   79,97   89,01   149,33   126,42   100,36   280,58   97,73   146,40   44,87   80,00   42,49   125,83   123,01   234,68   176,07   164,35   284,05   64,05   198,68   107,70   100,00   33,75   128,87   102,55   140,32   88,91   208,74   165,74   48,56   71,85   108,87   125,00   60,98   184,53   147,35   135,93   174,28   184,67   123,46   71,82   52,04   91,00   160,00   143,44   205,54   197,05   251,43   386,54   153,57   72,68   49,16   58,45   65,45   200,00   61,86   42,62   54,62   90,86   155,58   84,23   24,12   10,58   12,63   7,31   250,00   35,64   26,15   53,57   61,35   89,60   67,86   28,54   12,28   7,42   4,70   315,00   15,06   14,59   31,58   53,11   62,35   91,41   20,33   12,27   9,77   4,69   400,00   7,92   10,05   17,23   38,24   46,89   91,67   21,79   14,66   11,28   6,40   500,00   4,52   7,06   8,01   13,97   41,81   35,10   27,29   18,90   6,81   3,32        

Table  7.  Maximal  accelerations  from  Japanese  Ball  Amax  (m/s^2  rms)  positions  as  in  Figure  12.   Point   Amax  (m/s2)   Point   Amax  (m/s2)  

Acc1   1,09   Acc6   3,03  

Acc2   1,87   Acc7   2,29  

Acc3   1,94   Acc8   1,38  

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4.7.-­  Wall  Response  (only  one  of  LivRoom3  –furniture  on  others-­‐)  

 

The   objective   was   to   calculate   the   lowest   eigenfrequency   of   the   structure   when   hitting  the  wall  with  an  instrumental  hammer  with  a  rubber  tip  

 

  Figure  25  –  Measurement  disposition  on  the  wall  

 

 

Note:   This   measurement   could   only   be   done   for   the   inner   wall   in   LivRoom   3   as   indicated  in  Figure  4  as  the  others  were  covered  with  furniture  all  the  way.  And   note  also  that,  as  previously  mentioned  the  force  transducer  of  the  instrumented   hammer  available  didn’t  work.  

    0.83m Acc14 Excitation Response 1.33m 0.83m 1.33m Hammer

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Figure  27  -­‐  Vibrations  on  inner  –apartment  separating-­‐  wall  in  third-­‐octave  bands.  

   

4.8.-­  Springinness    

Not  performed,  as  the  instrumented  hammer  did  not  work.  

 

4.9.-­  Mobility  

 

Not  performed,  as  the  instrumented  hammer  did  not  work.  

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Drawings  of  Hyttkammaren.  

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References

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