ACTA MECHANICA SOLIDA SINICA he fractural work K, make the crack deflected and more energy dissipated and, therefore, reduce the brittleness of the material. The numerical simulation is in excellent agreement with the laboratory tests carried out by Cail3] and Tan[lal. The results from 2D numerical simulation performed by Chang[6 do not conflict with the present ones. The approaches adopted in this study can also be applied to other materials with laminated structure As a matter of fact, several toughening mechanisms may work together, however, the energy dissipation discussed in this section is the primary one elastic modulus(MPa)step 128(0) acoustic emission step 128-(0) X elastic modulus(MPa)step 99-(0) acoustic emission step 99(0) elastic modulus(MPa)step 96(0) astic modulus(MPa)step 98-0 acoustic emission step 98(0) acoustic emission step 80(0) specimen 5 (a) modulus V. CONCLUSION A large-scale three-dimensional simulation was conducted using parallel computer approaches. The fractural process of a beam model with soft layers under three-point loading was simulated. In the course· 146 · ACTA MECHANICA SOLIDA SINICA 2007 the fractural work K, make the crack deflected and more energy dissipated and, therefore, reduce the brittleness of the material. The numerical simulation is in excellent agreement with the laboratory tests carried out by Cai[13] and Tan[14]. The results from 2D numerical simulation performed by Chang[6] do not conflict with the present ones. The approaches adopted in this study can also be applied to other materials with laminated structure. As a matter of fact, several toughening mechanisms may work together, however, the energy dissipation discussed in this section is the primary one. V. CONCLUSION A large-scale three-dimensional simulation was conducted using parallel computer approaches. The fractural process of a beam model with soft layers under three-point loading was simulated. In the course