Craze Damage Field Near the Crack Tip of Non-crystalline Polymers
M. Jie,   C.C.Li  (Dept. Mech., Huazhong Univ. of Sci. & Tech., Wuhan, P.R.China)
Y.P.Li^ª¬  (Dept Civil Engng, Yueyang Univ., Yueyang, P.R.China )ª¬
£Ã.Y.Tang     (Dept Manufacturing Engng, The Hongkong Polytechnic Univ., Hong Kong )

Abstract: Craze damage is introduced in the plastic region near the crack tip of non-crystalline polymers. A modified Dugdale model is proposed, from which the size of t he plastic region is determined. Example shows that the craze damage leads to the increasing of the size of plastic region. Besides, the plastic region near the steadily extending crack tip is studied under Dugdale model. Based on such assumptions as slowly extending crack, small scale crazing and linear viscoelastic materials, etc., a nonlinear differential-integral equation governing the crack growth is obtained, via the energy principle. From this equation, it is found that the effect of craze damage is rather dominant.
Keywords: non-crystalline polymer, crack tip, craze damage.