PSI - Issue 28

Mikhail Perelmuter et al. / Procedia Structural Integrity 28 (2020) 2320–2327

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M.N. Perelmuter / Structural Integrity Procedia 00 (2020) 000–000

a )

b ) Fig. 5. The rates of deformation energy absorption by bonds for di ff erent values of relative materials sti ff ness vs the relative crack bridged length, t = d / : a ): for shear deformations, G x bond ( d , ); b ): for normal deformations, G y bond ( d , ).

a ) b ) Fig. 6. The rates of deformation energy absorption by bonds for di ff erent values of materials Poisson’s ratios vs the relative crack bridged length, t = d / : a ): for shear deformations, G x bond ( d , ); b ): for normal deformations, G y bond ( d , ). The dependencies of the rate of deformation energy absorption by bonds for di ff erent Poisson’s ratios of materials are shown in Fig. 6. Variation in the materials Poisson’s ratio at ( ν 1 = ν 2 = ν ) also (as in Fig. 5) leads to changing in the ratio between the terms of the rate of deformation energy absorption by bonds. With the decreasing in Poisson’s ratio, the contribution of shear deformations G x bond ( d , ) is increased and and G y bond ( d , ) decreases, while maintaining the total value of G bond ( d , ). The e ff ect of changing in bonds compliance along the crack bridging zone on the rate of deformation energy absorption by bonds is considered for functions of the form a ) γ ( ξ ) = 1 / 1 − ξ 2 , b ) γ ( ξ ) = 1 − ξ 2 , ξ = x (14) Fig. 7 shows the dependencies of the rate of absorption of deformation energy by bonds G bond ( d , ) and the term of this parameter corresponding to shear deformations G x bond ( d , ) with changing in bonds compliance along the crack bridging zone. Noticeable di ff erences are observed for the size of the bridging zone d / < 0 . 5. An increase in bond compliance (see relations (14), ξ → 1 corresponds to small size of bridged zone t = d / ) leads to decreasing in the