Factors affecting the limiting crack velocity in polymeric materials

It is often stated that the theoretical limit for the velocity of crack pro pagation in materials relates to the free surface Rayleigh wave velocity or other wave related criteria [Roberts DK, Wells AA. Engineering 1954;171:82 0; Field JE. Contemporary Physics, 1983;24(5):439; Schardin H. In: Averbach BL, Fellbeck DJK, Hahn GT, Thomas DA, editors. Fracture, chap. 16, New Yor k: Wiley, 1959; Anderson OL. In: Averbach BL, Fellbeck DJK, Hahn GT, Thomas DA, editors. Fracture, chap. 17, New York: Wiley, 1959.] However, the limi ting crack velocity in many materials is less than this theoretical limit a nd considerably so for tough polymers. Using experimental fracture data obt ained from a range of tough polymers, and a computer model in which toughne ss, stiffness and other material parameters can be independently varied, re lationships have been identified between limiting crack velocity and toughn ess properties of polymers. (C) 2000 Elsevier Science Ltd. All rights reser ved.