Federal Democratic Republic of Ethiopia ≠ EDICT OF GOVERNMENT ± In order to promote public education and public safety, equal justice for all, a better informed citizenry, the rule of law, world trade and world peace, this legal document is hereby made available on a noncommercial basis, as it is the right of all humans to know and speak the laws that govern them. ET ISO 16940 (2008) (English): Glass in building -- Glazing and airborne sound insulation -- Measurement of the mechanical impedance of laminated glass (cid:40)(cid:54)(cid:3)(cid:23)(cid:19)(cid:24)(cid:19)(cid:3) (cid:40)(cid:55)(cid:43)(cid:44)(cid:50)(cid:51)(cid:44)(cid:36)(cid:49) ES ISO (cid:20)(cid:25)(cid:28)(cid:23)(cid:19):2012 STANDARD (cid:3)(cid:3) (cid:3) (cid:3) (cid:3) (cid:41)(cid:76)(cid:85)(cid:86)(cid:87)(cid:3)(cid:72)(cid:71)(cid:76)(cid:87)(cid:76)(cid:82)(cid:81)(cid:3) (cid:3) (cid:3) (cid:3) (cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3) (cid:3) (cid:3) (cid:3) (cid:3) (cid:3) (cid:3) (cid:3) (cid:3) (cid:3) (cid:3) (cid:3) (cid:3) Glass i n building —— Glazing and airborne (cid:3)(cid:3)(cid:3)(cid:3) sound insulation —— Measurement of the mec(cid:3)hanical impedance of laminated (cid:3) glass (cid:3) (cid:3) (cid:3) (cid:3) (cid:3) (cid:3) (cid:3) (cid:3) Identical with ISO 16940:2008 (cid:3) (cid:3) (cid:3) (cid:3) (cid:3) (cid:3) (cid:3) (cid:3) (cid:3) (cid:3) (cid:3) (cid:3) (cid:3) (cid:3) (cid:3) (cid:3) (cid:3) (cid:3) (cid:3) (cid:3) (cid:3) (cid:3)     (cid:3)(cid:3)(cid:3)(cid:44)(cid:38)(cid:54)(cid:29)(cid:3)(cid:3)(cid:27)(cid:20)(cid:17)(cid:19)(cid:23)(cid:19)(cid:17)(cid:21)(cid:19)(cid:3) (cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3) (cid:3) (cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3) (cid:3) (cid:3) (cid:3) (cid:3) (cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)  (cid:3)      (cid:3)    (cid:3) (cid:3)(cid:3)(cid:3)(cid:3)(cid:51)(cid:88)(cid:69)(cid:79)(cid:76)(cid:86)(cid:75)(cid:72)(cid:71)(cid:3)(cid:69)(cid:92)(cid:3)(cid:40)(cid:87)(cid:75)(cid:76)(cid:82)(cid:83)(cid:76)(cid:68)(cid:81)(cid:3)(cid:54)(cid:87)(cid:68)(cid:81)(cid:71)(cid:68)(cid:85)(cid:71)(cid:86)(cid:3)(cid:36)(cid:74)(cid:72)(cid:81)(cid:70)(cid:92)(cid:3)(cid:3)(cid:3)(cid:3) (cid:3) (cid:3)(cid:3)(cid:3)(cid:139)(cid:3)(cid:40)(cid:54)(cid:36)(cid:3) (cid:40)(cid:54)(cid:3)(cid:44)(cid:54)(cid:50)(cid:3)(cid:20)(cid:25)(cid:28)(cid:23)(cid:19)(cid:29)(cid:21)(cid:19)(cid:20)(cid:21)(cid:11)(cid:40)(cid:12)     Foreword   This  Ethiopian  Standard  has  been  prepared  under  the  direction  of  the  Technical  Committee  for  (cid:18)(cid:286)(cid:396)(cid:258)(cid:373)(cid:349)(cid:272)(cid:853) (cid:3)(cid:410)(cid:286)(cid:396)(cid:396)(cid:258)(cid:272)(cid:381)(cid:410)(cid:410)(cid:258)(cid:3)(cid:271)(cid:367)(cid:282)(cid:3)(cid:373)(cid:258)(cid:410)(cid:286)(cid:396)(cid:349)(cid:258)(cid:367)(cid:400)(cid:853)(cid:3)(cid:920)(cid:3)(cid:336)(cid:367)(cid:258)(cid:400)(cid:400)  (TC  (cid:1007)(cid:1011))  and  published  by  the  Ethiopian  Standards  Agency  (ESA).       The  standard  is  identical  with  ISO  (cid:1005)(cid:1010)(cid:1013)(cid:1008)(cid:1004)(cid:855)(cid:1006)(cid:1004)(cid:1004)(cid:1012)  (cid:39)(cid:367)(cid:258)(cid:400)(cid:400)(cid:3)(cid:349)(cid:374)(cid:3)(cid:271)(cid:437)(cid:349)(cid:367)(cid:282)(cid:349)(cid:374)(cid:336)(cid:3)(cid:886)(cid:3)(cid:39)(cid:367)(cid:258)(cid:460)(cid:349)(cid:374)(cid:336)(cid:3)(cid:258)(cid:374)(cid:282)(cid:3)(cid:258)(cid:349)(cid:396)(cid:271)(cid:381)(cid:396)(cid:374)(cid:286)(cid:3)(cid:400)(cid:381)(cid:437)(cid:374)(cid:282)(cid:3)(cid:349)(cid:374)(cid:400)(cid:437)(cid:367)(cid:258)(cid:410)(cid:349)(cid:381)(cid:374)(cid:3)(cid:886)(cid:3) (cid:68)(cid:286)(cid:258)(cid:400)(cid:437)(cid:396)(cid:286)(cid:373)(cid:286)(cid:374)(cid:410)(cid:3)(cid:381)(cid:296)(cid:3)(cid:410)(cid:346)(cid:286)(cid:3)(cid:373)(cid:286)(cid:272)(cid:346)(cid:258)(cid:374)(cid:349)(cid:272)(cid:258)(cid:367)(cid:3)(cid:349)(cid:373)(cid:393)(cid:286)(cid:282)(cid:258)(cid:374)(cid:272)(cid:286)(cid:3)(cid:381)(cid:296)(cid:3)(cid:367)(cid:258)(cid:373)(cid:349)(cid:374)(cid:258)(cid:410)(cid:286)(cid:282)(cid:3)(cid:336)(cid:367)(cid:258)(cid:400)(cid:400)  published  by  (cid:47)(cid:374)(cid:410)(cid:286)(cid:396)(cid:374)(cid:258)(cid:410)(cid:349)(cid:381)(cid:374)(cid:258)(cid:367)(cid:3)(cid:381)(cid:396)(cid:336)(cid:258)(cid:374)(cid:349)(cid:460)(cid:258)(cid:410)(cid:349)(cid:381)(cid:374)(cid:3) (cid:296)(cid:381)(cid:396)  (cid:94)tandards  ((cid:47)(cid:94)(cid:75)).       For  the  purpose  of  this  Ethiopian  Standard  ,  the  adopted  text  shall  be  modified  as  follows.     (cid:891)(cid:3)The  phrase  “International  Standard”  shall  be  read  as  “Ethiopian  Standard”;  and     (cid:891)(cid:3)A  full  stop  (.)  shall  substitute  comma  (,)  as  decimal  marker. (cid:40)(cid:55)(cid:43)(cid:44)(cid:50)(cid:51)(cid:44)(cid:36)(cid:49) STANDARD(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:40)(cid:54)(cid:3)(cid:44)SO 16940:20(cid:20)(cid:21)(E) Glass in building —— Glazing and airborne sound insulation —— Measurement of the mechanical impedance of laminated glass 1 Scope This International Standard describes a method for the measurement of the loss factor and the equivalent bending rigidity modulus of laminated glass test pieces. The aim is to compare the properties of interlayers. These two parameters (and others such as density and thicknesses of glass components) can be related to the sound transmission loss (STL) of the glazing itself. NOTE The Cremer equation as shown in Annex C can be used to determine the sound transmission loss. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 12543-1:1998, Glass in building —— Laminated glass and laminated safety glass —— Part 1: Definitions and description of component parts ISO 140-1, Acoustics —— Measurement of sound insulation in buildings and of building elements —— Part 1: Requirements for laboratory test facilities with suppressed flanking transmission ISO 140-3, Acoustics —— Measurement of sound insulation in buildings and of building elements —— Part 3: Laboratory measurements of airborne sound insulation of building elements ISO 717-1, Acoustics —— Rating of sound insulation in buildings and of building elements —— Part 1: Airborne sound insulation 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 12543-1 and the following apply. 3.1 laminated glass assembly consisting of two sheets of glass joined together with the interlayer that will be characterized by the method of this International Standard NOTE 1 Adapted from ISO 12543-1:1998, definition 3.1. NOTE 2 The interlayer type and construction should be specified. (cid:139)(cid:3)(cid:3)(cid:3)(cid:40)(cid:3)(cid:3)(cid:3)(cid:54)(cid:3)(cid:3)(cid:36)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3) 1 ISO 16940:20 (E) 4 Test method 4.1 Measurement of mechanical impedance (MIM) of laminated glass 4.1.1 Principle The loss factor and the equivalent bending rigidity modulus are determined from the measurement of the input impedance of a glass beam sample. The input impedance is the transfer function between the injected force in one point and the velocity. This transfer function has resonances corresponding to a maximum of the response of the system (resonance frequency). 4.1.2 Measurement The input impedance is measured with an impedance head giving both parameters (force and velocity) at the fixation point of the tested structure. Tested samples are beams of dimensions (25 (cid:114) 2) mm ¥ (300 (cid:114) 1) mm; this limits the number of resonances in a given frequency band compared with a plate sample. The glass panes shall be nominally 4 mm thick for comparison purposes. The input impedance is measured at the centre of the sample, i.e. at half-length. For the fixation, good balance between left and right sides is needed, and the centre part shall be precisely determined. The vibration mode of the sample shall be as shown in Figure 1, i.e. a bending vibration of two ““free clamped”” half-beams. Figure 1 —— Examples of vibration modes The sample is glued (with a cyanoacrylic glue or equivalent) onto an impact button of 15 mm diameter. The impact button shall be flat (see Annex A). NOTE Fixation balance is easier to achieve with inverted V buttons, but flat buttons have been chosen because they are more readily available. A white noise type force between 0 Hz and 5 000 Hz is used. 2 (cid:139)(cid:40)(cid:54)(cid:36)(cid:3) ISO 16940:20 (E) 4.1.3 Determination of resonance frequencies and loss factors When the transfer function corresponding to the input impedance is measured, resonance frequencies, f , res,i are noted as well as the resonance curves for each resonance frequency (i index corresponding to ith resonance). Bandwidths used are sufficient to get good accuracy. By default, 1,25 Hz bandwidths are used. The loss factor is then calculated using Equation (1): (cid:39)f (cid:75) (cid:32) i (1) i f res,i as shown in Figure 2, and is a function of the frequency. Key X frequency, f (Hz) Y impedance, f/v Figure 2 —— Determination of the loss factor If the outcome (see Annex D) does not allow readable data to be obtained at ––3 dB on both sides of the peak, data at ––2 dB shall be used by using Equation (2): (cid:39) f (cid:39) f (cid:32) (cid:117)1,31 (2) f f (cid:16)2dB 4.1.4 Test equipment The measurement apparatus shall be set up as described in Annex A and composed of the following: 4.1.4.1 Environmental chamber or air conditioned room. 4.1.4.2 White noise generator. 4.1.4.3 Power amplifier. 4.1.4.4 Shaker. 4.1.4.5 Impedance head. 4.1.4.6 Two measuring amplifiers. 4.1.4.7 FFT dual channel analyser, plus calculation system. (cid:139)(cid:3)(cid:3)(cid:3)(cid:40)(cid:3)(cid:3)(cid:3)(cid:54)(cid:3)(cid:3)(cid:3)(cid:36)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3) 3 ISO 16940:20 (E) The apparatus shall be set up consistent with the dimensions and masses of the samples. The impedance head is an integrated system with a force transducer and an accelerometer. The force transducer is a transducer that generates an output voltage proportional to the input force. It is a piezoelectric sensor. The accelerometer is a transducer generating an output voltage proportional to the input acceleration. It may be piezoelectric, strain gauge, etc. The test equipment is shown in Annex A. A typical result is shown in Annex D. Calculations may be done directly from the analyser, or automatically with specific software. 4.2 Test procedure Measurements shall be carried out at (20 (cid:114) 1) °C. This parameter is very sensitive. The samples shall be kept for at least 1 h at the measurement temperature before performing the test. The values of the resonance frequency and of the loss factor for the first three modes shall be noted. The equivalent bending rigidity moduli for the first three modes should be calculated in accordance with Annex B. The corresponding sound transmission loss curves should be calculated for the third mode in accordance with Annex C. The weighted sound reduction index, R , in accordance with ISO 717-1, should be calculated and quoted to w one decimal place. 4.3 Test report The test report shall list the values of the resonance frequencies and loss factors for the first three modes. 4 (cid:139)(cid:40)(cid:54)(cid:36)(cid:3) ISO 16940:20 (E) Annex A (normative) Measurement set-up Key 1 thermometer 2 environmental chamber 3 specimen 4 impact button 5 instantaneous adhesive 6 shaker 7 impedance head 8 measuring amplifiers of mechanical impedance 9 power amplifier 10 FFT analyser 11 computer 12 noise generator Figure A.1 —— Apparatus set-up (cid:139)(cid:40)(cid:54)(cid:36)(cid:3) (cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)(cid:3)5 ISO 16940:20 (E) Annex B (normative) Determination of equivalent bending rigidity modulus The equivalent bending rigidity modulus, B , shall be determined for each resonance frequency from eq,i Equation (B.1): 2 (cid:167) 2(cid:83)L2 (cid:183) B (cid:32)m (cid:168) f (cid:184) (B.1) eq,i s(cid:168) res,i (cid:79)2 (cid:184) (cid:169) i (cid:185) where m is the density per surface unit of the sample, in kg/m2; s (cid:540) is a parameter (without dimension) given for free/clamped boundary conditions [1], [2] equal to: i 1,875 10 for i = 1; 4,694 10 for i = 2; 7,854 76 for i = 3; 10,995 54 for i = 4; L is the half-length of the beam, i.e. 150 mm. NOTE The resulting equivalent bending rigidity modulus, B (f ), is frequency dependent. eq,i res,i 6 (cid:139)(cid:40)(cid:54)(cid:36)(cid:3)