Vibroacoustic icr en

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  • 1. VIBR0ACOUSTIC Acoustic & Vibrations Engineering Services

2. R Far better an approximate answer to the right question,which is often vague, than an exact answer to the wrongquestion, which can always be made precise.John W. TukeyRIGHT QUESTIONS LEAD TO RIGHT ANSWERSI am not bound to swear allegiance to the dogmas of anymasterHoraceTHE GOOD THING OF A PROBLEM WITHOUT ANOBVIOUS SOLUTION IS THE PLEASURE IN FINDING ITI support that symbiogenesis is the result of a long timecoexistence and that is the main source of evolutionarynovelty in all superior non-bacterian organisms.Lynn MargulisFLUENT COMMUNICATION IS THE KEY TO PROGRESS 3. A WORK METHOD HistoryNoise and VibrationsICR is a company that works to solve noiseFor ICR, noise is closely connected toand vibration problems. vibrations, and vice versa, because vibrationsmake noise, and noise, when it touches a sur-It was established in 1995 by people with face, creates vibrations. A simultaneouswide experience in the world of is the only thing that makes theICR has always been involved in many impor- problem comprehensible and it enables thetant national and international technological company to find the solution.projects.To solve a problem, the company keeps aperfectbalance betweentheoreticalknowledge and a pragmatic point of view ofthe treatment of experimental data. The com-panys spirit is also practical it offersspecific answers to real problems, withmethods of analysis and the design ofsolutions.Thanks to its experience, its methodology isapplied successfully in a wide and variedrange of sectors.ICR currently holds a technical expertagreement with ENAC (National AccreditationEntity) to carry out noise and vibrationaudits.Analyser FFT 32 channelsTheory and Tests, Measurements in Real Time an Optimal CombinationICR has up to 48 channels to measure noiseand vibrations simultaneously, with therequired accelerometers and microphones.For ICR it has always been important toAll these elements analyse the signalinclude real tests in its studies, over theaccording to the frequency and in real timemany years of development and application they can analyse spectra, transfer func-of its own methods. The reason for this istions, coherence...that experimenting enables the company tounderstand the real situation and understandThe tests required can be performed effec-the problem directly, while the theorytively to find solutions for real vibroacousticenables the company to understand theproblems, thanks to the simultaneous controlanalysed reality and establish effectiveof a large amount of measurement points.modifications.The everyday work carried out at the com-This is why the company invests mostly inpany requires a large amount of technicaltwo areas: technology, to have the mostinstruments such as sound level meters, mi-advanced experimenting and analysiscrophones, accelerometers, spectra analys-methodology always available; and theers, etc. In order to carry out any project,ongoing training of its personnel.large or small. 4. ENGINEERING SERVICES RailwayICR has achieved an important position in therailway acoustic engineering sector in the lastdecade, thanks to its prediction techniques,based on real measurements and the appli-cation of the companys own theoreticalmethods.The company is able to measure air-bornenoise and structural noise, including the con-tribution of forces (Transfer Path Analysis)and the quantification of the paths followedby noise and vibrations (Advanced TransferGraphic of contributionsPath Analysis).ICRs clients will be able to know exactly howmuch noise is made by each element of the Thanks to its experience, ICR hastrain, for example, the noise received fromsound knowledge and latesteach point of attachment, the air condition-generation systems for the, the auxiliary systems, etc.This way, the manufacturer can decide, with Based on these studies, ICR carries out otherthe information available, whether to changetypes of jobs in the railway sectorsome ofthe anchoring methods and establish priori- them are specific to the sector, like the treat-ties for future modifications. For this, thement of squeal noise. Others, however,company uses exact numerical criteria fromhave a more generic application, like the en-the results that can be obtained from eachvironmental impact analysis, modal analysis,modification. theoretical numerical models of the train,etc.The knowledge of these contributions doesnot only establish priorities for modifica- Thanks to the companys wide experience intionsin some cases it can reduce costs be- this market, it is able to solve any vi-cause after each test, ICR evaluates improve- broacoustic problems.ments with its own software for a new designand defines the necessary changes to fulfilthe required objectives. The full acoustic model of a trainenables clients to see the effectproduced by any modifications on the design. Activate or deactivate anymodification and find out instantlyabout its effect on the total noise.Experimental setup 5. ENGINEERING SERVICESWind PowerWind farm are gradually being built closer tobuilt-up areas and the noise they produce isstarting to be an essential factor in theirfeasibility. In order to establish this feasibilityin terms of acoustic impact on the environ-ment, ICR carries out a comprehensive studyto make sure that regulations are compliedwith.It also develops more specific and largerprojects in the design stage of wind turbines,with the aim of obtaining real predictions forthe future vibroacoustic performance or themechanism.Training is so another very important servicein the wind power sector. ICR gives veryspecific courses to companies that manufac-ture wind-driven turbines, with a syllabus thatis adapted to the sector and introducedconcepts on acoustics and its relation withcurrent legislation. ICR works on the acoustic feasibility the wind turbine in design phaseas the environmental control of Sound power level measurement according tothe wind farm. standard IEC 61400 part 11Environmental impact study of the wind farm 6. ENGINEERING SERVICES BuildingPeoples peace and quiet is often disturb bydifferent problems entertainment, fairs,bars, discos, etc. To avoid this problem, cur-rent legislation establishes the maximumimmission level allowed for every activity de-pending on the area, as well as the insulationvalues for each type of activity.Taking this into account, ICR mainly developstwo types of studies:Noise prediction radiated by equipments The objective of the first study is to assessand prevent the noise level generated by theactivities outside. This type of analysis isICR offers a wide range of engineeringcarried out especially at discos, fairs,services and vibroacoustic consultancyrecreational centres, etc.service focused on the sector of architectureand building, namely: The second one studies the transmissionpaths of noise and vibrations inside a Functional solutionsbuilding. The aim of these projects is to as- Insulation calculationsess the sound insulation between the Acoustic and vibration measurementsaffected buildings. Control and monitoring works Acoustic conditioning and insulation design The company also carries out comprehen- Acoustic and vibratory impact studysive interior acoustics projects (geometry,absorption, diffusion) in the field ofFinally, we have to mention that ICR hasaudiovisualsinstalling a sound system, developed new systems to identify the sourcemixing and recording systems, and control orof noise and vibrations in buildings, usingdesign of new and quieter recreationalmodel inversion and other methods like TPA.centres.Special BuildingsIn the building sector, the company takespart in special and very complex projects, inwhich it evaluates the future influence ofenvironmental vibrations in buildings wherethe maximum vibration level is veryrestricted.This study is carried out firstly by calculatingthe environmental vibrations that may affecttheinstallations,andsecondly, bycharacterising the terrain with the SASWmethod (Spectral Analysis of Surface Waves).The data obtained is used to create a finiteImprove the insulation of a discotheque element model of the terrain and thebuilding. 7. TECHNIQUES/METODOLOGY Environmental ImpactThe concern for noise impact created by thenew high-speed train tracks is no longer asecondary factor when planning infrastruc-tures.ICR carries out environmental projects to pre-dict noise and vibrations with a methodologybased generally on the combination of thecalculation of noise prediction with acousticAcoustic impact caused by the train circulation in Gironameasurements. ICR believes that measuringproperly will lead to a good vibroacousticcharacterisation of the terrain, and therefore,to a good numerical model.The company also has the best calculationtools, such as CADNA A and SOUNDPLAN,which enables us to obtain highly reliableresults for our most demanding clients.Noise predictions for trains and road trafficare currently regulated by European stan-dards, which are integrated into the com-Acoustic impact by road traffic in Ronda de Daltpanys calculation procedures.of Barcelona ICR carries out projects and evaluation measurements every day to calculatethe impact of roads and railway tracks. AutomotiveOur work in the car industry ranges from ex-perimental studies on the transmission pathsof noise and vibrations, to the creation oftheoretical models to predict the noise oftraffic.We must not forget the development of new To determine the noise transmission pathstesting methods that optimise time and costsof each of the interior panels of vehicle in the current methodology to characterise avehicle. Most acoustics laboratoriesBecause the methods we use are transpar-of car industries apply theoretical ent, our clients have been able to gain moreinsight into vibroacoustics and thus reduce approach of TPA/ATPA costs when resolving noise and vibration developed by IC