Z.-L. Guo’s scientific contributions

A new Dopple detection system (DPS) array and a high-speed framing camera are used to test the surface dynamics and local velocity profiles of the expansion, fracture propagation and rupture of TC4 case initiated by high explosive for the research on complex dynamic response of metal case at high-strain rate. The engineering strain at the moment of surface crack initiation and explosion product leakage is estimated through comparative analysis, and the surface crack mode and the influence of crack initiation on velocity profiles are observed. Furthermore, The fracture property of metal case is confirmed from the fracture morphologies of recovered fragments.

Relying on the explosively driven setting of one-end detonator initiation and using the Doppler velocimetry and high-speed framing camera, we diagnosed the expansion and fracture process of the cylindrical shell. The results obtained from our experiment provide the velocity-time history of the shell surface and its dynamic snapshots referring to expansion deformation, crack initiation and propagation, and explosion product leakage. The results from the SPH simulation are in reasonably good agreement with the experimental findings. Systemic analysis of experiments and simulations determine incident angle of shock wave for cylindrical shell, releasing angle of explosion wave, velocity and pressure profile of internal wall and deformed strain, fracture process of cylindrical shell.

An experimental platform is built to investigate the dynamic fragmentation of multiple metal rings, the layout of multiple metal rings, initiation system and principle, are detailed. Then the platform is applied to conduct the dynamic loading of pure aluminium and oxygen-free electronic copper materials, and the fractured strain and statistical distribution of reassembled fragments are obtained. It is shown that the experimental platform can achieve simultaneous and stable loading of multiple metal rings. Morever, the statistical distribution is well fitted by the Weibull function. ©, 2015, Chinese Journal of High Pressure Physics. All right reserved.

The finite element program LS-DYNA3D and the molecular dynamic method were applied to investigate the plastic zone formation, evolution process and the consequent dynamic failure behaviors under the dynamic tensile loading in a metal sheet with a preset flaw at macroscopic and microscopic levels, respectively. The calculated results show that the formation of the plastic zone stems from the stress wave-flaw and stress wave-stress wave interactions. The macroscopic and microscopic simulations represent the similar physical characteristics: the crack initiates at the front of the flaw boundary, then connects with the flaw and eventually leads to the global failure.