Advertisement

Application of the Caustic Method to an Environmental Crack-Craze Growth Problem

  • K. Takahashi
  • N. Takeda
  • A. E. Abo-El-Ezz

Abstract

The stress intensity factor KI(c) is a controlling parameter for craze initiation and growth at crack tips of linear glassy polymers in environmental liquids (Marshall 1970). However, as the craze grows larger than the one which the Dugdale model (Dugdale 1960) assumes, linear fracture mechanics fails to describe the craze growth behavior. The caustic method is applied to a study of the environmental crack-craze stress field in poly(methyl methacrylate)(PMMA). The change of the caustic shape and size reflecting the nonuniform stress state along a craze is experimentally correlated with the craze growth behavior (Abo-El-Ezz). The caustic method was originally based on an elastic assumption (Mannog 1966; Theocaris 1970) and later was applied to materials displaying a large amount of plasticity and strain-hardening (Theocaris 1973, 1974). The two-step stress distribution model along a craze is introduced for a quantitative analysis by the elasto-plastic caustic theory (Takeda). The theoretical caustic shape and size based on this model is then compared with the experimental results.

Keywords

Stress Intensity Factor Linear Fracture Mechanic Dugdale Model Initial Curf Craze Growth 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Abo-El-Ezz AE, Takeda N, Takahashi K (to be published) Caustics observations for a study of environmental crack-craze stress fields. J Mater SciGoogle Scholar
  2. Brown WF Jr, Srawley JE (1966) Plane-strain crack toughness testing of high-strength metallic materials. ASTM STP 410Google Scholar
  3. Dugdale DS (1960) Yielding of steel sheets containing slits. J Mech Phys Solids 8: 100–108CrossRefADSGoogle Scholar
  4. Mannog P (1966) Die Lichtablenkung durch eine elastisch beanspruchte Platte und die Schattenfiguren von Kreis-und Risskerbe. Glastechnische Berichte 39: 323–329Google Scholar
  5. Marshall GP, Culver LE, Williams JG (1970) Craze growth in polymethylmethacrylate: a fracture mechanics approach. Proc Roy Soc London A319: 165–187ADSGoogle Scholar
  6. Sakurada Y, Takahashi K (1981) Measurement of the stress-intensity factor for poly(methyl methacrylate) cracks by using the method of caustics. Kobunshi Ronbunshu 38: 369–375 (in Japanese)CrossRefGoogle Scholar
  7. Takeda N, Abo-El-Ezz AE, Takahashi K (to be submitted) The modified theory of caustics for evaluation of the environmental craze stress distribution.Google Scholar
  8. Theocaris PS (1970) Local yielding around a crack tip in plexiglas. J Appl Mech Trans ASME Ser E 37: 409–415CrossRefGoogle Scholar
  9. Theocaris PS (1973) Stress intensity factors in yielding materials by the method of caustics. Int J Frac 9: 185–196CrossRefGoogle Scholar
  10. Theocaris PS, Gdoutos E (1974) The modified Dugdale-Barenblatt model adapted to various fracture configurations in metals. ibid 10: 549–564CrossRefGoogle Scholar
  11. Williams JG (1984) Fracture mechanics of polymers. Ellis Horwood Ltd, Chichester, p 191Google Scholar

Copyright information

© Springer-Verlag Tokyo 1986

Authors and Affiliations

  • K. Takahashi
    • 1
  • N. Takeda
    • 1
  • A. E. Abo-El-Ezz
    • 1
  1. 1.Research Institute for Applied MechanicsKyushu UniversityKasuga-koen, Kasuga, Fukuoka 816Japan

Personalised recommendations