Papers by Author: Wei Yang

Abstract: Using classical explicit nonlinear dynamic analysis software of ANSYS/LS-DYNA, this paper analyzes the process of perforating jet penetrating on four types of concrete target with unconfined compressive strength of 30 MPa, 50 MPa, 30 MPa & 50 MPa and 50 MPa & 30 MPa. The result shows that penetration of shaped charge will decrease if cross-formation perforation occurs and in order to guarantee the penetration performance during perforating, perforating should be parallel to the direction of oil formation and be avoided from working on high-strength tight formation and up-and-down cap-rock.

Abstract: A molecular colloidal shear thickening fluid (STF), polyborondimethylsioxane (PBDMS) was synthesized, which differs from traditionally studied Silica/PEG system. Differential Scanning Calorimetry (DSC), the controlled stress rheometer.etc, were used to characterize the produced PBDMS. Scanning Electron Microscope (SEM) is the method to get the surface morphology of the Kevlar fabric impregnated by the fluid. Meanwhile the ballistic and stab tests of the composites materials were investigated.

Abstract: The hyperelastic constitutive model of cardiac muscle is developed based on the animal surgical operation and mechanical experiments from the heart of the dogs, and the relaxation phenomena is also studied based on the Hill three elements model which is viscoelastic. Some numerical simulations are presented by finite element for the cardiac pacing/defibrillation lead interaction with muscles of the heart.

Abstract: Applications of above-coercive electric fields lead to domain switching of a large or global scale. Large scale switching model is proposed to deal with load-induced domains witching in experiment. Both a discussion of crack initiation via the stress intensity factor and a discussion of crack path stability via T-stress are presented. The theoretical predictions and the experimental data roughly coincide for crack initiation, propagation and stability phenomena. Attention is also extended to consider the effect of non-uniform ferro-elastic domain switching in the vicinity of a crack. The domain switching zone is divided into a saturated inner core and an active surrounding annulus. Toughening for ferroelectrics with different poling states is estimated via Reuss type approximation. Solutions obtained according to spherical and cylindrical inclusions cover the range of experimental data.