Sound Emission Analysis - Revision history

Oluschinski at 13:25, 12 December 2025

2025-12-12T13:25:02Z

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	==General==		==General==

	One method of [[Materials Testing\|materials testing]] that has gained importance in recent years is sound emission analysis (SEA) or [[Sound Emission Testing\|sound emission testing]]. This is an acoustic testing method for investigating [[Sound Emission\|sound emissions]] with the aim of determining the type and condition of the sound sources and the exciting stress process. The cause of [[Acoustic Emission\|acoustic emissions]] ([[Sound Emission\|sound emissions]], SE) in the form of elastic stress waves can be seen, for example, in damage to [[Phase Boundary\|phase boundary]] areas in [[Fibre-reinforced Plastics\|fibre-reinforced plastics]] or [[Crack Formation\|crack formation]] and [[Crack Propagation\|crack propagation]] processes, which act as sound sources and result from mechanical (over)stress (see: [[Stress#Mechanical stress\|mechanical stress]]). These processes can be detected using suitable measurement technology.		One method of [[Materials Testing\|materials testing]] that has gained importance in recent years is sound emission analysis (SEA) or [[Sound Emission Testing\|sound emission testing]]. This is an acoustic testing method for investigating [[Sound Emission\|sound emissions]] with the aim of determining the type and condition of the sound sources and the exciting stress process. The cause of [[Acoustic Emission\|acoustic emissions]] ([[Sound Emission\|sound emissions]], SE) in the form of elastic stress waves can be seen, for example, in damage to [[Phase Boundary Surface\|phase boundary]] areas in [[Fibre-reinforced Plastics\|fibre-reinforced plastics]] or [[Crack Formation\|crack formation]] and [[Crack Propagation\|crack propagation]] processes, which act as sound sources and result from mechanical (over)stress (see: [[Stress#Mechanical stress\|mechanical stress]]). These processes can be detected using suitable measurement technology.

	==Setting up a sound emission workplace==		==Setting up a sound emission workplace==
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	The sound emission analysis method is classified as a quasi-[[Non-destructive Testing ~~Method~~\|non-destructive testing ~~method~~]] in [[Materials Testing\|materials testing]]. The reasons for this are that, on the one hand, it is linked to active defects under external load (destructive), but on the other hand, the [[Sound Emission\|sound emissions]] occur long before the [[Fracture\|ultimate material failure]]. [[Acoustic Emission\|Acoustic emission]] tests on metals and [[Plastics\|plastics]] are carried out in the frequency range between 50 kHz and 2 MHz.		The sound emission analysis method is classified as a quasi-[[Non-destructive Testing (NDT)\|non-destructive testing]] method in [[Materials Testing\|materials testing]]. The reasons for this are that, on the one hand, it is linked to active defects under external load (destructive), but on the other hand, the [[Sound Emission\|sound emissions]] occur long before the [[Fracture\|ultimate material failure]]. [[Acoustic Emission\|Acoustic emission]] tests on metals and [[Plastics\|plastics]] are carried out in the frequency range between 50 kHz and 2 MHz.

	The mechanical stress waves propagate spherically from the point of origin. They can be converted into analogue electrical signals at any point on the [[Plastic Component\|component]] using a [[Piezoelectric Ceramic Transducer\|piezoelectric ceramic transducer]]. As it propagates through the material, the original signal undergoes numerous changes due to [[Dispersion\|dispersion]] and [[Ultrasonic Waves Reflection\|reflection]], which is why the received signal has little in common with the original signal. This means that a square wave pulse becomes a long, slowly rising and falling signal.		The mechanical stress waves propagate spherically from the point of origin. They can be converted into analogue electrical signals at any point on the [[Plastic Component\|component]] using a [[Piezoelectric Ceramic Transducer\|piezoelectric ceramic transducer]]. As it propagates through the material, the original signal undergoes numerous changes due to [[Dispersion\|dispersion]] and [[Ultrasonic Waves Reflection\|reflection]], which is why the received signal has little in common with the original signal. This means that a square wave pulse becomes a long, slowly rising and falling signal.

Oluschinski at 13:29, 5 December 2025

2025-12-05T13:29:54Z

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Oluschinski: Created page with "{{Language_sel|LANG=ger|ARTIKEL=Schallemissionsanalyse}} {{PSM_Infobox}} Sound emission analysis FORCETOC ==General== One method of materials testing that has gained importance in recent years is sound emission analysis (SEA) or sound emission testing. This is an acoustic testing method for investigating sound emissions with the aim of determin..."

2025-12-05T13:26:52Z

Created page with "{{Language_sel|LANG=ger|ARTIKEL=Schallemissionsanalyse}} {{PSM_Infobox}} <span style="font-size:1.2em;font-weight:bold;">Sound emission analysis</span> __FORCETOC__ ==General== One method of materials testing that has gained importance in recent years is sound emission analysis (SEA) or sound emission testing. This is an acoustic testing method for investigating sound emissions with the aim of determin..."

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{{Language_sel|LANG=ger|ARTIKEL=Schallemissionsanalyse}}
{{PSM_Infobox}}
<span style="font-size:1.2em;font-weight:bold;">Sound emission analysis</span>
__FORCETOC__

==General==

One method of [[Materials Testing|materials testing]] that has gained importance in recent years is sound emission analysis (SEA) or [[Sound Emission Testing|sound emission testing]]. This is an acoustic testing method for investigating [[Sound Emission|sound emissions]] with the aim of determining the type and condition of the sound sources and the exciting stress process. The cause of [[Acoustic Emission|acoustic emissions]] ([[Sound Emission|sound emissions]], SE) in the form of elastic stress waves can be seen, for example, in damage to [[Phase Boundary|phase boundary]] areas in [[Fibre-reinforced Plastics|fibre-reinforced plastics]] or [[Crack Formation|crack formation]] and [[Crack Propagation|crack propagation]] processes, which act as sound sources and result from mechanical (over)stress (see: [[Stress#Mechanical stress|mechanical stress]]). These processes can be detected using suitable measurement technology.

==Setting up a sound emission workplace==

The following '''Fig. 1''' shows a schematic representation of the basic setup of a workplace for sound emission analysis.

[[File:Sound_Emission_Analysis-1.jpg|500px]]
{|
|- valign="top"
|width="50px"|'''Fig. 1''':
|width="600px" |Basic set-up of a sound emission workplace
|}

The sound emission analysis method is classified as a quasi-[[Non-destructive Testing Method|non-destructive testing method]] in [[Materials Testing|materials testing]]. The reasons for this are that, on the one hand, it is linked to active defects under external load (destructive), but on the other hand, the [[Sound Emission|sound emissions]] occur long before the [[Fracture|ultimate material failure]]. [[Acoustic Emission|Acoustic emission]] tests on metals and [[Plastics|plastics]] are carried out in the frequency range between 50 kHz and 2 MHz.

The mechanical stress waves propagate spherically from the point of origin. They can be converted into analogue electrical signals at any point on the [[Plastic Component|component]] using a [[Piezoelectric Ceramic Transducer|piezoelectric ceramic transducer]]. As it propagates through the material, the original signal undergoes numerous changes due to [[Dispersion|dispersion]] and [[Ultrasonic Waves Reflection|reflection]], which is why the received signal has little in common with the original signal. This means that a square wave pulse becomes a long, slowly rising and falling signal.

Other reasons for changes to the original signal are:

* Material-intrinsic loss mechanisms
* Influences of the sensor system
* Smearing due to extraneous noise

In addition, the useful signal of the [[Sound Emission|sound emission]] depends on the following factors.

* [[Viscosity]] of the coupling medium
* Layer thickness of the contact
* Surface quality of the component or [[Specimen|test specimen]]
* Contact pressure between the transducer and the [[Surface|surface]]
* Transducer mass

The signal obtained can take various forms, which provide information about processes occurring in the material. On the one hand, there is continuous [[Acoustic Emission|emission]] ('''Fig. 2'''), as observed in [[Deformation#Plastic deformation|plastic]], homogeneous deformations of metals. On the other hand, there are burst signals ('''Fig. 3'''), which occur in [[Crack Formation|crack formation]], [[Crack Propagation|crack propagation]] and [[Friction Force|friction]] processes, among others.

[[File:kont_emission.jpg|300px]]
{|
|- valign="top"
|width="50px"|'''Fig. 2''':
|width="600px" |Continuous emission
|}

[[Datei:burstsignal.jpg|300px]]
{|
|- valign="top"
|width="50px"|'''Fig. 3''':
|width="600px" |Burst signals
|}

The fact that [[Acoustic Emission|acoustic emissions]] only occur during mechanical [[Stress|stressing]] requires the coupling of acoustic emission analysis with a mechanical [[Materials Testing|material testing]] method. To date, [[Quasi-static Test Methods|quasi-static tests]] such as [[Tensile Test|tensile]] or [[Bend Test|bend tests]] have most commonly been coupled with acoustic emission analysis (see '''Fig. 4''').

[[File:sea_zv.jpg|400px]]
{|
|- valign="top"
|width="50px"|'''Fig. 4''':
|width="600px" | [[Tensile Test#Tensile test, stress–strain diagram|Stress–strain curve]] (blue) and number of acoustic emissions (red) of glass fibre-reinforced polyamide 6 in a short-term tensile test
|}

==Coupling sound emission analysis with the instrumented Charpy impact test==

The recording of [[Sound Emission|sound emissions]] during impact (dynamic) stress (see: [[Impact Loading Plastics|impact loading plastics]]) for the purpose of evaluating the [[Micro-damage Limit|onset of damage]] is of particular practical relevance.

'''Figure 5''' shows an example of an investigation in which the [[Instrumented Charpy Impact Test|instrumented Charpy impact test]] (ICIT) was coupled with sound emission analysis (SEA) to record the [[Acoustic Emission|acoustic emissions]]. With the aid of wavelet transformation (see: [[Frequency Analysis|frequency analysis]]), it is possible to assign damage to a frequency range (see: [[Frequency Analysis|frequency analysis]]).

[[File:Sound_Emission_Analysis-5.jpg|650px]]
{|
|- valign="top"
|width="50px"|'''Fig. 5''':
|width="600px" |Result of coupling [[ICIT with AE]] for a polypropylene [[Short-fibre Reinforced Plastics|reinforced with short glass fibres]] at 20 m.-%
|}

==See also==

* [[Sound Emission|Sound emission]]
* [[Sound Emission Testing|Sound emission testing]]
* [[Ultrasonic Birefringence|Ultrasonic birefringence]]
* [[Ultrasonic Sensors|Ultrasonic sensors]]
* [[ICIT with AE|ICIT with AE]]

'''Reference'''

* Bardenheier, R.: Schallemissionsuntersuchungen an polymeren Verbundwerkstoffen. Part I: Das Schallemissionsmessverfahren als quasi-zerstörungsfreie Werkstoffprüfung Zeitschrift für Werkstofftechnik 11 (1980) pp. 41–46
* Schoßig, M.: Mechanische und bruchmechanische Bewertung von kurzglasfaserverstärkten Polyolefinwerkstoffen unter quasistatischer und dynamischer Beanspruchung. Vieweg+Teubner | Springer Fachmedien Wiesbaden GmbH (2011), (ISBN 978-3-8348-1483-8; see also [[AMK-Büchersammlung|AMK-Library]] under B 1-21) [https://www.polymerservice-merseburg.de/fileadmin/inhalte/psm/veroeffentlichungen/Schossig_Promotion_Inhaltsverzeichnis.pdf Content as pdf]

[[Category:Acoustic Test Methods_Ultrasonics]]