ACTA MECHANICA SOLIDA SINICA elastic modulus(MPa)step 12-(0) nax principal stress(MPa) step 12(0 elastic modulus(MPa)step 16-(0 max principal stress(MPa)step 16-(0) elastic modulus(MPa) step 26(0) max principal stress(MPa) step 26(0) elastic modulus(MPa)step 30H-(0) Lax principal stress(MPa)step 30(0) elastic modulus(MPa)step 4G(0 Imax principal stress(MPa) step 46(0) (a)modulus (b) max principal stress Fig 3. Fractural processes of laminated model in this block do not propagate horizontally On the other hand, from Fig 4(b), though most AE event occur along the vertical direction, more AE events could be found in the horizontal one. It is quite clear that most horizontal AE events are located within soft layers. In addition, the radii of AE events shown in Fig 4(a) do not change rapidly from the area near the bottom of the beam to the upper part This shows that the energy dissipated from each cells in the fracture belt is almost at the same level But it can be seen from Fig 4(b) that the energy dissipated from the vertical cracks is much greater than that in the horizontal direction. The same conclusion can also be obtained from Ref. 15 in the 2D condition· 144 · ACTA MECHANICA SOLIDA SINICA 2007 Fig. 3. Fractural processes of laminated model. in this block do not propagate horizontally. On the other hand, from Fig.4(b), though most AE events occur along the vertical direction, more AE events could be found in the horizontal one. It is quite clear that most horizontal AE events are located within soft layers. In addition, the radii of AE events shown in Fig.4(a) do not change rapidly from the area near the bottom of the beam to the upper part. This shows that the energy dissipated from each cells in the fracture belt is almost at the same level. But it can be seen from Fig.4(b) that the energy dissipated from the vertical cracks is much greater than that in the horizontal direction. The same conclusion can also be obtained from Ref.[15] in the 2D condition