Sonoprobe method has been applied in non-destructive inspection of anchorage project. The fundament is that dynamic transient excitation causes the elastic vibration of an anchor bar, and flaws can be estimated or ded...Sonoprobe method has been applied in non-destructive inspection of anchorage project. The fundament is that dynamic transient excitation causes the elastic vibration of an anchor bar, and flaws can be estimated or deduced by determining transient response of the anchor bar. FEA numeric solution of hyperbolic equation indicates that deductions must comply with acoustic parameters such as velocity of sound, vibration range, wave shape etc when inspecting interior flaws in the grout of an anchor bar. Based on wavelet packet analysis, the energy eigenvector is a flaw vector, which could be regarded as the basis in the nondestructive inspection of anchors. As a non-linear dynamical system, artifical neural networks dealing with quality inspection of gray system have been proved efficient.展开更多
The steel bonded carbide, a composite material, is very difficult to be machined to a fine finish mirror surface. In this paper, an electrolytic in-process dressing (ELID) grinding with metallic bond super-hard abrasi...The steel bonded carbide, a composite material, is very difficult to be machined to a fine finish mirror surface. In this paper, an electrolytic in-process dressing (ELID) grinding with metallic bond super-hard abrasive wheel was developed for grinding steel bonded carbide GT35. Factors affecting ELID grinding performance were analyzed by an atomic force microscope (AFM). Based on the analysis of AFM topography of the fine ground mirror surface of the steel bonded carbide, a schematic diagram of the mechanism of micro-removal of the ground surface was described. The AFM topography also shows that the hard brittle carbide particles, on the surface of steel bonded carbide, were machined out by ductile cutting. Since the grinding cracks in the ground surface are due to temperature gradient, temperature distribution in the grinding area was analyzed by finite element method (FEM). Experimental results indicate that a good mirror surface with Ra<0.02pm can be obtained by the developed ELID grinding system.展开更多
基金Funded by High-tech Foundation of National Planning Committee (No. [1992]2062)
文摘Sonoprobe method has been applied in non-destructive inspection of anchorage project. The fundament is that dynamic transient excitation causes the elastic vibration of an anchor bar, and flaws can be estimated or deduced by determining transient response of the anchor bar. FEA numeric solution of hyperbolic equation indicates that deductions must comply with acoustic parameters such as velocity of sound, vibration range, wave shape etc when inspecting interior flaws in the grout of an anchor bar. Based on wavelet packet analysis, the energy eigenvector is a flaw vector, which could be regarded as the basis in the nondestructive inspection of anchors. As a non-linear dynamical system, artifical neural networks dealing with quality inspection of gray system have been proved efficient.
文摘The steel bonded carbide, a composite material, is very difficult to be machined to a fine finish mirror surface. In this paper, an electrolytic in-process dressing (ELID) grinding with metallic bond super-hard abrasive wheel was developed for grinding steel bonded carbide GT35. Factors affecting ELID grinding performance were analyzed by an atomic force microscope (AFM). Based on the analysis of AFM topography of the fine ground mirror surface of the steel bonded carbide, a schematic diagram of the mechanism of micro-removal of the ground surface was described. The AFM topography also shows that the hard brittle carbide particles, on the surface of steel bonded carbide, were machined out by ductile cutting. Since the grinding cracks in the ground surface are due to temperature gradient, temperature distribution in the grinding area was analyzed by finite element method (FEM). Experimental results indicate that a good mirror surface with Ra<0.02pm can be obtained by the developed ELID grinding system.
