WO1996035942A1 - Procede d'analyse permettant de reconnaitre des etats de tension dans des corps solides - Google Patents

Procede d'analyse permettant de reconnaitre des etats de tension dans des corps solides Download PDF

Info

Publication number
WO1996035942A1
WO1996035942A1 PCT/EP1996/001897 EP9601897W WO9635942A1 WO 1996035942 A1 WO1996035942 A1 WO 1996035942A1 EP 9601897 W EP9601897 W EP 9601897W WO 9635942 A1 WO9635942 A1 WO 9635942A1
Authority
WO
WIPO (PCT)
Prior art keywords
solid
energy
frequency
intensity
measuring
Prior art date
Application number
PCT/EP1996/001897
Other languages
German (de)
English (en)
Inventor
Gert Goch
Bernhard Schmitz
Stefan Hock
Klaus Lechleiter
Wolf Burkart
Original Assignee
Zf Friedrichshafen Ag
Institut für Lasertechnologien in der Medizin und Meßtechnik an der Universität Ulm
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Zf Friedrichshafen Ag, Institut für Lasertechnologien in der Medizin und Meßtechnik an der Universität Ulm filed Critical Zf Friedrichshafen Ag
Priority to EP96919692A priority Critical patent/EP0824687A1/fr
Publication of WO1996035942A1 publication Critical patent/WO1996035942A1/fr

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L1/00—Measuring force or stress, in general
    • G01L1/24—Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis using infrared, visible light, ultraviolet
    • G01L1/248—Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis using infrared, visible light, ultraviolet using infrared
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N25/00—Investigating or analyzing materials by the use of thermal means
    • G01N25/72—Investigating presence of flaws

Definitions

  • the invention relates to a method for the detection of mechanical stress states, in particular of internal stresses and load stresses (compressive stress or tensile stress), in a solid body which absorbs energy (light, electromagnetic radiation, etc.).
  • the principle of the measuring method is based on the fact that a solid during periodic or pulsed irradiation with high-energy radiation also heats up periodically in accordance with the modulation frequency or pulse sequence of the excitation source at the irradiated locations due to the absorption of the radiation energy, and the heat generated from the location of the irradiation spreading out as a thermal wave in the solid.
  • the properties of this thermal wave with regard to amplitude and phase relationship between the excitation and response signals depend on the properties of the solid. Amplitude and phase signals are therefore suitable measurands for describing the thermal properties of a solid.
  • a solid If a solid is subjected to high-energy, intensity-modulated radiation, heat is generated at the location of the radiation absorption and the heating spreads out as a periodically varying temperature in the form of a thermal wave in the solid.
  • the heat expansion and the resulting temperature distribution is physically described by the heat diffusion equation with location-dependent thermal properties (thermal conductivity, density, heat capacity) of the solid. It follows from this equation that the depth of penetration of the damped and highly dispersive thermal wave penetrating into the solid has a strong dependence on the modulation frequency of the exciting radiation.
  • both the amplitude and the phase of the thermal response signal to the excitation frequency contain information about the material property and its change, whereby it should be noted that the thermal properties, in particular the thermal diffusivity and thermal effusivity (which again in a different way from thermal conductivity, density and heat capacity), depending on the microscopic properties of the material, such as. B. the voltage states.
  • the amplitude contains information on the absorption coefficient and the thermal characteristics of the body being examined. It depends on the optical, thermal and geometric properties of the sample surface.
  • the phase relationship between the excitation and the thermal response signal contains information about the propagation behavior of the thermal wave in the solid and is thus influenced by material properties which influence the diffusion of the heat, that is to say the thermal diffusivity. Since the propagation behavior of the signal in the solid also depends on the modulation frequency of the excitation source, information from different depths and surrounding distances from the excitation location can also be received by the response signal by changing the modulation frequency.
  • the thermal characteristics in particular the thermal diffusivity, change at different locations. Since the thermal diffusivity or the thermal parameters are in turn dependent on the microscopic state of the material, the material state can also be inferred from this, the depth profile of the thermal properties being correlated with the course of stress states in the interior of the material.
  • response-dependent frequency signals are obtained from the same distances due to the spherical propagation of a wave, which correspond to a spherical surface, but which lie in different depth ranges of the solid.
  • This can be partial be undesirable since only one response signal from a certain depth is required in each case, in particular since residual stresses are also often depth-dependent.
  • it is advantageous to provide a large excitation surface relative to the measurement surface of the response signal and / or the depth of penetration of the signal into the solid body, the measurement surface being in each case sufficiently spaced from the edges of the excitation surface. This ensures that the response signal is almost one-dimensional and changes in the signal are only depth-dependent.
  • the diffusion equation at the measurement site also becomes one-dimensional and mathematical models can be used to reconstruct the only depth-dependent thermal parameters from the frequency profile of the thermal signals (amplitude and phase).
  • the surface of a solid is excited on an excitation surface A with an intensity-modulated, energy-carrying radiation with a modulation frequency f, whereby any radiation can be used.
  • An intensity-modulated laser in the visible to ultraviolet range is preferably used here, but simple light, high-energy X-ray radiation or other electromagnetic radiation, high-energy electron radiation or other particle radiation can also be used.
  • the energy response of the solid body with respect to intensity and / or phase shift to the modulation frequency is measured, the heat response (according to the Planck 1 see steel law) preferably being included here
  • An infrared sensitive detector is measured.
  • Other detection methods such as photothermal beam deflection, interferometry, thermal reflection, beam deflection in reflection, can also be used if the geometric conditions at the measuring location allow this.
  • This measurement is carried out for a multiplicity of different modulation frequencies f x at the same measuring location and a comparison of the intensity and / or phase profile between a standard solid of the same material or another location of the specimen and the specimen to be examined is made via the frequencies f x performed.
  • This comparison preferably consists in a simple subtraction (phase signal) or quotient formation (amplitude signal) of the values of the corresponding excitation frequency, as a result of which a so-called contrast curve is obtained.
  • a change in the thermal properties up to a depth predetermined by the modulation frequency and thus the presence of a tension state of the sample body at the location to be examined can be concluded.
  • the frequency-dependent amplitude and phase contrast functions differ characteristically in the case of existing tensile or compressive stresses, so that the ratio at different modulation frequencies is sufficient to clearly distinguish tensile and compressive stresses.
  • the size is to be correlated with the level of tensile or compressive stress. It is therefore emphasized that a calibration must be carried out for each base material, since the correlation of tensile and compressive stresses with the changes in the thermal parameters is material-specific.
  • a device for detecting stress states, in particular residual stresses (compressive stress or tensile stress) in an energy-absorbing solid requires the following units: a source for emitting an intensity-modulated, energy-carrying excitation radiation with a
  • Modulation frequency f which irradiates an excitation surface A on the solid; a measuring device for registering the energy response of the solid (detector) with respect to intensity and / or phase shift to the modulation frequency on a measuring surface m on the solid; an electronic unit (with periodic excitation: lock-in amplifier), which determines the amplitude and phase from the modulator and detector signals; an electronic system that compares the intensity and / or phase curve between one
  • the device can also be designed in such a way that the measuring area m is so much smaller than A that m lies within A, so that influences from the edge areas are negligible.
  • the device according to the invention can additionally or exclusively be equipped with a measuring device for registering the mirage effect for registering the heat response of the solid.
  • the measuring device can advantageously also be equipped with an infrared detector for measuring the energy response of the solid.
  • an electronic system which is suitable: between the two measuring locations or specimens to calculate the contrast curve over the frequency (difference of the measured values depending on the frequency) and / or - the state of tension of the specimen at the location to be examined due to the change in contrast and
  • the last-mentioned measuring devices can also be used according to the invention to carry out an automatic production control in a production process or to detect the wear condition of a tool over a longer period of time on the basis of several comparative measurements and to determine an optimized replacement time of the tool.
  • this method can sweep the surface of a solid and in this way, for example, to display one or more flat images on which the course of the thermal parameters is shown at different depths, the The size and direction of the gradient can be specified in color or by gray values.
  • Fig. 1 basic principle of the measuring arrangement
  • Fig. 2 different variations of 4 to 4 measuring devices according to the invention.
  • Fig. 1 shows the principle of the measuring arrangement.
  • a relatively large excitation area A is subjected to an intensity-modulated radiation (shown here as a chopper) with a modulation frequency f.
  • the radiation strikes the surface and generates thermal waves according to their modulation frequency, the wave fronts of which are shown in simplified form as dashed lines.
  • the solid body emits response signals corresponding to the thermal waves, which are imaged over the measuring surface m in the form of emerging infrared radiation onto an answer detector via an optical element (shown in FIG. 1 as a lens, but also possible as a mirror) which is focused on the surface m by a lens.
  • an optical element shown in FIG. 1 as a lens, but also possible as a mirror
  • a suitable selection of the dimensions of A and m in the area of the measuring surface gives me an area in which the wavefronts spread linearly, so that a one-dimensional, only depth-dependent Response signal can be detected, which is to be interpreted using the diffusion equation.
  • 2 shows a possible arrangement of a measuring device.
  • a laser is shown as the radiation source, the light of which is modulated by a chopper, the information about the respective modulation frequency being transmitted to an electronic system via the information line II.
  • the response signal is measured simultaneously via a response detector and also passed directly to the electronic system via the information line 12.
  • the response detector consists of an infrared-sensitive receiver.
  • the upstream imaging optical element (identified as a lens in FIG. 2) can consist of an IR-transparent lens, a combination of lenses, a mirror, a combination of mirrors or a combination of lenses and mirrors hen.
  • FIG. 3 An alternative embodiment of this is shown in FIG. 3, in which, instead of detecting IR radiation, the effect of the thermal waves on the surrounding medium is measured by deflecting a laser beam due to the temperature-related change in the refractive index.
  • the well-known Mirage effect is used here.
  • Other (not shown here) alternative detection methods are thermal reflection, beam deflection in reflection, photothermal interferometry.
  • FIGS. 4 finally shows a combination of the two principles from FIGS. 2 and 3, the measurement signals here also being forwarded via the information lines II - 13 to the electronic unit and then to the electronic system for evaluation for storage and documentation be directed.
  • the electronic system itself also features via appropriate storage units, e.g. B. to compare and evaluate the previously measured measured values of standard samples with the results of the solid to be assessed or with measured values from other places on the same body according to the above-mentioned method.
  • the results are transferred to a display or a printer.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Investigating Or Analyzing Materials Using Thermal Means (AREA)

Abstract

L'invention concerne un procédé et un dispositif qui permettent de reconnaître des états de tension dans un corps solide capable d'absorber de l'énergie. La surface du corps solide est excitée par un rayonnement porteur d'énergie à intensité modulée. L'intensité et/ou le déphasage par rapport à la fréquence de modulation de la réponse énergétique du corps solide sont mesurés. On compare ensuite le résultat de la mesure à la courbe d'intensité et/ou de phase d'un corps de référence constitué du même matériau. Cette comparaison permet de déterminer la présence d'un état de tension du corps solide à l'endroit analysé.
PCT/EP1996/001897 1995-05-10 1996-05-07 Procede d'analyse permettant de reconnaitre des etats de tension dans des corps solides WO1996035942A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP96919692A EP0824687A1 (fr) 1995-05-10 1996-05-07 Procede d'analyse permettant de reconnaitre des etats de tension dans des corps solides

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19517133.0 1995-05-10
DE1995117133 DE19517133A1 (de) 1995-05-10 1995-05-10 Untersuchungsverfahren zur Erkennung von Spannungszuständen in einem Festkörper

Publications (1)

Publication Number Publication Date
WO1996035942A1 true WO1996035942A1 (fr) 1996-11-14

Family

ID=7761557

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP1996/001897 WO1996035942A1 (fr) 1995-05-10 1996-05-07 Procede d'analyse permettant de reconnaitre des etats de tension dans des corps solides

Country Status (3)

Country Link
EP (1) EP0824687A1 (fr)
DE (1) DE19517133A1 (fr)
WO (1) WO1996035942A1 (fr)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10003921C2 (de) * 2000-01-29 2002-03-07 Kleinhuis Hermann Gmbh Einbaudose zur Verwendung in einem Kabelkanal, wie Brüstungskanal
DE102021127596A1 (de) 2021-10-22 2023-04-27 Linseis Messgeräte Gesellschaft mit beschränkter Haftung Temperaturleitfähigkeitsmessgerät

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4468136A (en) * 1982-02-12 1984-08-28 The Johns Hopkins University Optical beam deflection thermal imaging
EP0347641A2 (fr) * 1988-06-21 1989-12-27 Hans-Joachim Dipl.-Phys. Sölter Procédé et appareil pour l'examen sans contact de la surface et de l'intérieur d'un corps solide
GB2237113A (en) * 1989-09-19 1991-04-24 Atomic Energy Authority Uk Thermographic inspection

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4468136A (en) * 1982-02-12 1984-08-28 The Johns Hopkins University Optical beam deflection thermal imaging
EP0347641A2 (fr) * 1988-06-21 1989-12-27 Hans-Joachim Dipl.-Phys. Sölter Procédé et appareil pour l'examen sans contact de la surface et de l'intérieur d'un corps solide
GB2237113A (en) * 1989-09-19 1991-04-24 Atomic Energy Authority Uk Thermographic inspection

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
CRETIN B ET AL: "METALLURGICAL APPLICATIONS OF THE THERMOELASTIC MICROSCOPE", THIN SOLID FILMS, vol. 209, no. 1, 15 March 1992 (1992-03-15), pages 127 - 131, XP000261315 *

Also Published As

Publication number Publication date
EP0824687A1 (fr) 1998-02-25
DE19517133A1 (de) 1996-11-14

Similar Documents

Publication Publication Date Title
EP0058710B1 (fr) Procede et dispositif d'analyse photo-thermique et sans contact des structures internes et proches de la surface d'un corps solide
EP0362307B1 (fr) Mesurage de la temperature par ultrasons et application en spectroscopie optique et en calorimetrie
DE1573401C3 (de) Anordnung zur zerstörungsfreien Werkstoffprüfung auf verborgene Defekte
DE112006001786B4 (de) Verfahren und System zum Bestimmen von Materialeigenschaften mittels Ultraschalldämpfung
DE10053112A1 (de) Vorrichtung und Verfahren zur thermografischen Analyse von Prüflingen
DE4015893C2 (de) Verfahren und Vorrichtung zur Untersuchung der inneren Struktur eines absorptionsfähigen Prüflings
EP1134579A2 (fr) Procédé et appareil pour l'analyse photothermique d'une couche de matériau, notamment pour la mesure de l'épaisseur de la couche
DE602005002348T2 (de) Verfahren zur messung von teilcheneigenschaften mittels interferenzstreifenanalyse und entsprechende vorrichtung
DE102008048266B4 (de) Verfahren zur schnellen Bestimmung der separaten Anteile von Volumen- und Oberflächenabsorption von optischen Materialien, eine Vorrichtung hierzu sowie deren Verwendung
DE19729280C1 (de) Ultraschallmikroskop
EP0824687A1 (fr) Procede d'analyse permettant de reconnaitre des etats de tension dans des corps solides
DE4016105B4 (de) Verfahren und Vorrichtung zur Erfassung von Oberflächenstrukturen
EP1087229A2 (fr) Méthode et appareil pour la détection des défauts par ultrasons
DE4300378A1 (en) Contactless material investigation by laser - illuminating by pulsed laser with variable radiated energy density, pressure or acoustic sensor.
WO2021151792A1 (fr) Procédé et dispositif de caractérisation d'un champ lumineux cohérent en amplitude et en phase
EP4146507A1 (fr) Procédé de test d'une couverture de coussin gonflable de sécurité comportant une ligne de rupture prédéterminée présentant une résistance définie à la déchirure
DE3510314A1 (de) Verfahren und vorrichtung zur beruehrungslosen pruefung von materialien auf inhomogenitaeten
DE102015205400A1 (de) Verfahren und System zur Untersuchung des Polymerisationsgrads eines aushärtbaren Polymers
DE102021118888B4 (de) Vorrichtung und Verfahren zur Ermittlung der Temperaturwechselbeständigkeit eines Prüfkörpers
DE102004038282B4 (de) Verfahren zur Untersuchung auf einem Metallsubstrat aufgebrachter, mit Partikeln durchsetzter Beschichtungen
DE3442061A1 (de) Verfahren zum zerstoerungsfreien pruefen inhomogener werkstoffe
EP0435829B1 (fr) Arrangement pour l'analyse d'ondes thermiques dans des systèmes en couches
DE2646972C2 (de) Akusto-optischer Wandler zum Empfang von Ultraschallwellen bei der zerstörungsfreien Werkstoffprüfung
DE3710323C2 (fr)
DE102018222369B3 (de) Verfahren und Vorrichtung zur zerstörungsfreien Prüfung eines Objekts

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): JP US

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FI FR GB GR IE IT LU MC NL PT SE

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
121 Ep: the epo has been informed by wipo that ep was designated in this application
WWE Wipo information: entry into national phase

Ref document number: 1996919692

Country of ref document: EP

WWP Wipo information: published in national office

Ref document number: 1996919692

Country of ref document: EP

WWR Wipo information: refused in national office

Ref document number: 1996919692

Country of ref document: EP

WWW Wipo information: withdrawn in national office

Ref document number: 1996919692

Country of ref document: EP