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The Shadow Optical Method of Caustics

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Part of the book series: International Centre for Mechanical Sciences ((CISM,volume 290))

Abstract

The shadow optical method of caustics is a relatively new experimental technique in stress strain analysis. It was introduced by Manogg1,2 in 1964. The method is sensitive to stress gradients and therefore is an appropriate tool for quantifiying stress concentration problems. Manogg originally used the method for investigating crack tip stress intensifications. The technique was extended later by Theocaris3–5, Rosakis6,7, and the author and his colleagues8–11 to different conditions of loading, material behavior, in static as well as dynamic situations. Shadow optical images of test specimens under loading in general are characterized by very simple geometric patterns which can be easily evaluated. Because of the simplicity of shadow patterns, the method can also be successfully applied for investigating rather complex phenomena, for example transient problems. Despite the complexity which may be inherent in the problems to be investigated the clearness of the generated recordings allows the derivation of reliable informative data. The author and his colleagues have applied the caustic technique to investigate various problems of practical interest in the field of fracture dynamics, in particular to the behavior of propagating and subsequently arresting cracks and the behavior of cracks under different impact loading conditions.

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Abbreviations

a:

Crack length

a,b:

Elasto-optical constants

A,B:

Material constants in Maxwell-Neumann’s law

α:

Velocity dependent factor

a2,3,4... :

Coeffients of higher order terms in crack tip stress distribution

c:

Shadow optical constant

co :

Sound wave speed

c1 :

Longitudinal wave speed

c2 :

Transverse wave speed

C:

Compliance of specimen

d:

1. Specimen thickness

2. Distance between two cracks in double crack configuration

deff :

Effective thickness of the specimen

D:

Characteristic length parameter for caustic evaluation

Do,i :

Outer, inner characteristic length parameter

Dmax,min :

Maximum, minimum length parameter of mixed mode caustics

e:

Index characterizing elastic behavior

E:

Young’s modulus

ε:

Strain

f:

Numerical factor for caustic evaluation

fo,i :

Numerical factor for evaluating outer, inner caustic

g:

Numerical factor for KI-determination from mixed mode caustics

G:

1. Function

2. Lamé’s constant, G = E/2(1+ν)

H:

Height of specimen

In :

Numerical Factor in the HRR stress field equations

J:

J-Integral

K:

Stress intensity factor

n:

1. Refractive index

2. Strain hardening coefficient

ν:

Poisson’s ratio

O:

Origin of coordinate system

p:

Edge load, unit N/m

P:

Index characterizing plastic behavior

p,q:

Biaxial stresses in y,x-direction

R:

Radius of circular hole

r,φ:

Polar coordinate system in object plane (specimen)

r′,φ′:

Polar coordinate system in image (reference) plane

:

Polar coordinate system at the tip of a moving crack

ro :

Radius of initial curve

rpl :

Radius of plastically deformed region around the crack tip

rps :

Smallest radius around the center of stress concentration outside which a state of plane stress exists

ρ:

1. Density of the material

2. Notch tip radius

3. Wedge tip radius

S:

Support span

s:

Optical path length

σ:

Normal stress

σo :

Tensile yield stress

t:

Time

λ:

Coefficient of anisotropy

τ:

1. Shear stress

2. Period of the oscillation of impacted specimen

µ:

Ratio of the mode II to mode I stress intensity factor, KII/KI

u,v,w:

Displacements in x,y,z-direction

W:

Width of the specimen

x,y:

Cartesian coordinates system in object plane (specimen)

x′,y′:

Cartesian coordinates system in image (reference) plane

:

Cartesian coordinates system at the tip of a moving crack

z:

Direction of optical axis

zo :

Distance between object plane (specimen) and image (reference) plane

References

  1. Manogg, P., “Anwendung der Schattenoptik zur Untersuchung des Zerreißvorgangs von Platten”, Dissertation, Freiburg, Germany, 1964

    Google Scholar 

  2. Manogg, P., “Schattenoptische Messung der spezifischen Bruchenergie während des Bruchvorgangs bei Plexiglas”, Proc. Int. Conf. on the Physics of Non-Crystalline Solids, Delft, The Netherlands, 1964, 481–490

    Google Scholar 

  3. Theocaris, P.S., and Joakimides, N., “Some Properties of Generalized Epicycloids Applied to Fracture Mechanics”, Journ. Appl. Mech., 22, 1971, 876–890

    MATH  Google Scholar 

  4. Theocaris, P.S., “The Reflected Caustic Method for the Evaluation of Mode III Stress Intensity Factor”, Int. Journ. Mech. Sci., 23, 1981, 105–117

    Article  MATH  MathSciNet  Google Scholar 

  5. Theocaris, P.S., “Stress Concentrations at Concentrated Loads”, Experimental Mechanics, 13, 1973, 511–528

    Article  Google Scholar 

  6. Rosakis, A.J., Freund, L.B., “Optical Measurement of the Plastic Strain Concentration at a Tip in a Ductile Steel Plate”, Journ. Engr. Mat. Tech., 104, 1982, 115–125

    Article  Google Scholar 

  7. Rosakis, A.J., Ma, C.O., Freund, L.B., “Analysis of the Optical Shadow Spot Method for a Tensile Crack in a Power-Law Hardening Material”, Journ. Appl. Mech., 50, 1983, 777–782

    Article  ADS  Google Scholar 

  8. Kalthoff, J.F., Beinert, J., Winkler, S., “Analysis of Fast Running and Arresting Cracks by the Shadow-Optical Method of Caustics”, I.U.T.A.M. Symposium on Optical Methods in Mechanics of Solids, Ed. A. Lagarde, University of Poitiers, France, Sept. 10–14, 1979, Sijthoff and Nordhoff, 1980, 497–508

    Google Scholar 

  9. Beinert, J., Kalthoff, J.F., “Experimental Determination of Dynamic Stress Intensity Factors by Shadow Patterns”, in: “Mechanics of Fracture, Vol. 7, Experimental Fracture Mechanics”, Ed. G.C. Sih, Martinus Nijhoff Publishers, The Hague, Boston, London, 1981, 280–330

    Google Scholar 

  10. Kalthoff, J.F., “Stress Intensity Factor Determination by Caustics”, Proc. Int. Conf. on Experimental Stress Analysis, organized by Japan Society of Mechanical Engineers (JSME) and American Society for Experimental Stress Analysis (SESA), Honolulu-Maui, Hawaii, May 23–29, 1982, 1119–1126

    Google Scholar 

  11. Kalthoff, J.F., Böhme, W., Winkler, S., “Analysis of Impact Fracture Phenomena by Means of the Shadow Optical Method of Caustics”, Proc. VIIth Int. Conf. on Experimental Stress Analysis, organized by SESA, Haifa, Israel, Aug. 23–27, 1982, 148–160

    Google Scholar 

  12. Born, M., Wolf, E., “Principles of Optics”, Pergamon Press, Oxford, London, Edinburgh, New York, Paris, Frankfurt, 1970

    Google Scholar 

  13. Broek, D., “Elementary Engineering Fracture Mechanics”, Martinus Nijhoff Publishers, The Hague, Boston, London, 1982

    Book  Google Scholar 

  14. Paris, P.C., Sih, G.C., “Stress Analysis of Cracks”, Fracture Toughness Testing and its Application, ASTM STP 381, American Society for Testing and Materials, Philadelphia, 1965, 30–83

    Book  Google Scholar 

  15. Theocaris, P.S., “Complex Stress Intensity Factors of Bifurated Cracks”, Journ. Mech. Phys. Solids, 20, 1972, 265–279

    Article  ADS  Google Scholar 

  16. Seidelmann, U., “Anwendung des schattenoptischen Kaustikenverfahrens zur Bestimmung bruchmechanischer Kennwerte bei überlagerter Normal-und Scherbeanspruchung”, Bericht 2/76 des Fraunhofer-Instituts für Festkörpermechanik, Freiburg, 1976

    Google Scholar 

  17. Sih, G.C., “Handbook of Stress Intensity Factors”, Institute of Fracture and Solid Mechanics, Lehigh University, Bethlehem, Pa., 1973

    Google Scholar 

  18. Freund, L.B., “Crack Propagation in an Elastic Solid Subjected to General Loading–I. Constant Rate of Extension”, Journ. Mech. Phys. Solids, 20, 1972, 129–140

    Article  ADS  MATH  MathSciNet  Google Scholar 

  19. Kalthoff, J.F., “Zur Ausbreitung und Arretierung schnell laufender Risse”, Fortschritt-Berichte der VDI-Zeitschriften, Reihe 18, Nr. 4, VDI-Verlag, Düsseldorf, 1987, 1–95

    Google Scholar 

  20. Williams, M.L., “On the Stress Distribution at the Base of a Stationary Crack”, Journ. Appl. Mech., 24, 1957, 109–114

    MATH  Google Scholar 

  21. Hutchinson, J.W., “Plastic Stress and Strain Fields of a Tensile Crack”, J.urn. Mech. Phys. Soldids, 16, 1968, 13–31

    Article  ADS  MATH  Google Scholar 

  22. Rice, J.R., Rosengreen, G.F., “Plane Strain Deformation Near a Crack Tip in a Power Law Hardening Material”, Journ. Mech. Phys. Solids, 16, 1968, 1–12

    Article  ADS  MATH  Google Scholar 

  23. Hutchinson, J.W., “Plastic Stress and Strain Fields of a Crack Tip”, J.urn. Mech. Phys. Solids, 16, 1968, 337–347

    Article  ADS  Google Scholar 

  24. Kalthoff, J.F., Winkler, S., Beinert, J., “The Influence of Dynamic Effects in Impact Testing”, Int. Journ. of Fracture, 13, 1977, 528–531

    Google Scholar 

  25. Kalthoff, J.F., Böhme, W., Winkler, S., Klemm, W., “Measurements of Dynamic Stress Intensity Factors in Impacted Bend Specimens”, CSNISpecialist Meeting on Instrumented Precracked Charpy-Testing, Electric Power Research Institute, Palo Alto, Calif., Dec. 1–3, 1980, 1–17

    Google Scholar 

  26. Kalthoff, J.F., Winkler, S., Bohne, W., Klemm, W., “Determination of the Dynamic Fracture Toughness Kid in Impact Tests by Means of Response Curves”, Proc. 5th Int. Conf. on Fracture, Cannes, March 29–April 3, 1981, in “Advances in Fracture Research”, Pergamon Press, 1981, 363–373

    Google Scholar 

  27. ASTM E 399, “Standard Test Method for Plane-Strain Fracture Toughness of Metallic Materials”, Annual Book of ASTM Standards, Part 10, American Society for Testing and Materials, Philadelphia, 1983

    Google Scholar 

  28. Ireland, D.R., “Critical Review of Instrumented Precracked Charpy Testing”, Proc. Int. Conf. D.namic Fracture Toughness, London, July 5–7, 1976, 47–62

    Google Scholar 

  29. Kalthoff, J.F., Winkler, S., Beinert, J., “Dynamic Stress Intensity Factors for Arresting Cracks in DCB Specimens”, Int. Journ. of Fracture, 12, 1976, 317–319

    Article  Google Scholar 

  30. Kalthoff, J.F., Beinert, J., Winkler, S., “Measurements of Dynamic Stress Intensity Factors for Fast Running and Arresting Cracks in Double-Cantilever-Beam Specimens”, Fast Fracture and Crack Arrest, ASTM STP 627, Eds. G.T. Hahn and M.F. Kanninen, American Society for Testing and Materials, Philadelphia, 1977, 161–176

    Chapter  Google Scholar 

  31. Kalthoff, J.F., Beinert, J., Winkler, S., Klemm, W., “Experimental Analysis of Dynamic Effects in Different Crack Arrest Test Specimens”, Crack Arrest Methodology and Applications, ASTM STP 711, Eds. G.T. Hahn and M.F. Kanninen, American Society for Testing and Materials, Philadelphia, 1980, 109–127

    Chapter  Google Scholar 

  32. Kalthoff, J.F., “Bruchdynamik laufender und arretierender Risse”, Int. Seminar über Bruchmechanik, Schadensanalyse für die Praxis, Bruchsicherheit, Ed. H.P. Rossmanith, Wien, 12./13. Juni 1980, K 1–22; published in “Grundlagen der Bruchmechanik”, Ed. H.P. Rossmanith, Springer Verlag, Wien, New York, 1982, 191–219

    Google Scholar 

  33. Crosley, P.B., Ripling, E.J., “Characteristics of a Run-Arrest Segment of Crack Extension”, Fast Fracture and Crack Arrest, ASTM STP 627, Eds. G.T. Hahn and M.F. Kanninen, American Society for Testing and Materials, Philadelphia, 1977, 203–227

    Chapter  Google Scholar 

  34. Hahn, G.T., et al., “Critical Experiments, Measurements and Analyses to Establish a Crack Arrest Methodology for Nuclear Pressure Vessel Steels”, Reports BMI-1937, 1959, 1985 prepared for U.S. Nuclear Regulatory Commission, Battelle Columbus Laboratories, Ohio, 1975–1978

    Google Scholar 

  35. Kalthoff, J.F., Winkler, S., “Fracture Behavior under Impact”, First Annual Report prepared for United States Army, European Research Office, IWM Report W 8/82, Fraunhofer-Institut für Werkstoffmechanik, Freiburg, 1983

    Google Scholar 

  36. Kalthoff, J.F., Winkler, S., “Fracture Behavior under Impact”, Second Annual Report prepared for United States Army, European Research Office, IWM Report W 10/82, Fraunhofer-Institut für Werkstoffmechanik, Freiburg, 1983

    Google Scholar 

  37. Kalthoff, J.F., “On Some Current Problems in Experimental Fracture Dynamics”, Workshop on Dynamic Fracture, Ed. W.G. Knauss, California Institute of Technology, Pasadena, Calif., Feb. 17–18, 1983, 11–35

    Google Scholar 

  38. Cranz, C. and Schardin, H., “Kinematographie auf ruhendem Film und mit extrem hoher Bildfrequenz”, Z. Phys. 56, 1929, 147–183

    Article  ADS  Google Scholar 

  39. Mach, E., Berichte der Wiener Akademie. Abs. 2a, 92, 625, 1885

    Google Scholar 

  40. Stenzel, A., “Elektronisch gesteuerte Cranz-Schardin-Funkenzeitlupe”, Proc. IV. Int. Congr. High-Speed Phot. Köln, Hellwich, Darmstadt, 1959, 136–138

    Google Scholar 

  41. Vollrath, K., “Funkenlichtquellen und HF-Funkenkinematographie”, Kurzzeitphysik, Ed. K. Vollrath und G. Thomer, Springer, 1967, 76–157

    Google Scholar 

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© 1987 Springer-Verlag Wien

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Kalthoff, J.F. (1987). The Shadow Optical Method of Caustics. In: Lagarde, A. (eds) Static and Dynamic Photoelasticity and Caustics. International Centre for Mechanical Sciences, vol 290. Springer, Vienna. https://doi.org/10.1007/978-3-7091-2630-1_4

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  • DOI: https://doi.org/10.1007/978-3-7091-2630-1_4

  • Publisher Name: Springer, Vienna

  • Print ISBN: 978-3-211-81952-4

  • Online ISBN: 978-3-7091-2630-1

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