Papers by Author: Yong Wang

Abstract: It is great significance to study self-healing aluminum alloy materials for spacecraft the structure protection from high energy space weapon attack and debris impact in future. In this paper, Using aluminum alloy (6063) as matrix material with low melting point alloy (Sn60Pb40, the melting point of 183°C) as repairing materials, the self-healing Aluminum Alloy material was designed and manufactured by the smelting and casting method. The crack damage repair performance of the self-healing Al alloy was researched through the experiment. The results show that the self-healing aluminum alloy has certain self-healing ability without help, when the temperature reaches the melting point temperature of Sn60Pb40. The repair time is about 20min, the crack filling rate can reach 84%. The research conclusion can provide a reference for the development of metal self-healing material technology.

Abstract: In this paper, the authors employ the M/M/1 system and single-queue and single-server system of gated service, the information packets of Bi-directional cable network are calculated and analyzed theoretically, and the loss rate of information packet is also simulated by computer compared to the theoretical analysis in the paper. Simulation results show that the theoretical analysis and simulation are consistent.And the information packet of Bi-directional cable TV network using single-queue and single-server system’s loss rate analysis of information packet in the transformation provides reference to the theoretical analysis and computer simulation.

Abstract: For the implementation of digital multimedia communication, an efficient, reliable, deterministic transmission system plays a vital role. Quadrature amplitude modulation (QAM) is commonly used in digital communication systems. We focuses on simulation and analysis of M-level QAM by using MATLAB in this paper.

Abstract: A mechanical model of the visco-elastic compressible material is established in order to investigate the viscous effect in dynamic growing crack-tip field. The constitutive equations on the visco-elastic compressible material are deducted. Through asymptotic analysis, it is shown that in the stable creep growing stage, the elastic-deformation and the visco-deformation are equally dominant in the near-tip field, as 1 ( 1) n r− − . The asymptotic solutions of separative variable in the crack-tip field are aslo obtained. According to numerical calculation, the curves of stress, stain and displacement are given. The results indicate that the near-tip fields are mainly governed by the creep exponent n and Mach number M ; the stress fields of mode I and mode II is slightly affected by the elastic compressible deformation; the strain and displacement fields of mode I are deeply affected by the elastic compressible deformation. However, the strain and displacement fields of mode II are less affected by the elastic compressible deformation. The asymptotic solutions of dynamic growing crack-tip field gained here can conveniently degenerate the incompressible case, when the Poisson ratio 0.5 ν→ , named as HR field. The conclusions can provide the references for further studying the dynamic growing crack-tip field in compressible material.

Abstract: Based on the strain energy function proposed by GAO Y C and the theory of finite deformation dynamics, the question about the cavity dynamic formation and bifurcation of the incompressible homogeneous solid sphere under a suddenly applied uniform tensile dead-load was studied. The condition under which a dynamic bifurcated solution exists was examined. The relationship between the dead-load and the cavity radius, the critical load, the stress distributions after the cavity formation, the vibration phase diagram of the cavity radius and the approximate vibration period were also determined.

Abstract: In this paper, the conception of natural fracture stress in rocks is given according to mesomechanics analysis. The quantitative analysis about wellbore collapse and stratum fracture is made and the density range of drilling fluid is determined. The result is the same as the conclusion which was given by the traditional Mohr-Coulomb criterion in petroleum engineering. The new method of combining mesomechanics with fracture mechanics is used to study the wellbore stability in petroleum engineering, which can reveal the nature of the rock deformation mechanism and provide theoretical reference to design of the drilling engineering.