相关统计技术在力学检测中的应用

通过对Q235A热轧圆盘条抗拉强度过程能力指数和化学成分进行统计分析．确定了抗拉强度和化学成分的相关性．建立和验证了两者之间的多元回归函数关系．并通过回归方程来词整钢材的化学成分，从而提高过程能力指数。     

Strain Measurement in a Shape Memory Alloy with Strain Gauges

Abstract:  The recovery of shape due to temperature-induced martensite to austenite phase transformation in shape memory alloys (SMA), such as nickel titanium alloys, has been investigated and utilised in applications for many years. One of the problems in incorporating SMA in host materials, such as composites, is the poor bonding characteristics of the SMA. A closely related problem in experiments is the measurement of strains in SMA specimens; as thin wires have been used in many of the experimental investigations, strains have been deduced from length measurements. In the current work, electrical resistance strain gauges have been bonded on SMA strips. Tensile strains up to 8% during tensile loading as well as compressive strains during strain recovery due to subsequent heating have been measured. Strains determined by other methods, such as extensometer and length measurements, are also reported and compared. The major contribution of this work is the successful bonding of strain gauges on SMA and the measurement of large strains (up to 8%).     

Plasma transferred arc deposition of beryllium

The exceptional properties of beryllium (Be), including low density and high elastic modulus, make it the material of choice in many defense and aerospace applications. However, health hazards associated with Be material handling limit the applications that are suited for its use. Innovative solutions that enable continued use of Be in critical applications while addressing worker health concerns are highly desirable. Plasma transferred arc solid free-form fabrication is being evaluated as a Be fabrication technique for civilian and military space-based components. Initial experiments producing Be deposits are reported here. Deposit shape, microstructure, and mechanical properties are reported. This article was originally published inBuilding on 100 Years of Success, Proceedings of the 2006 International Thermal Spray Conference (Seattle, WA), May 15–18, 2006, B.R. Marple, M.M. Hyland, Y.-Ch. Lau, R.S. Lima, and J. Voyer, Ed., ASM International, Materials Park, OH, 2006.     

Numerical modeling of the dynamic tensile behavior of irregular fibers

Most fibers are irregular and are often subjected to rapid straining during mechanical processing and end‐use applications. In this article, the effect of fiber dimensional irregularities on the dynamic tensile behavior of irregular fibers was examined using the finite‐element method (FEM). Fiber dimensional irregularities are simulated with sine waves of different magnitude (10, 30, and 50% level of diameter variation). The tensile behavior of irregular fibers was examined at different strain rates (333, 3333, and 30,000%/s). The breaking load and breaking extension of irregular fibers at different strain rates were then calculated from the finite‐element model. The results indicate that strain rate has a significant effect on the dynamic tensile behavior of an irregular fiber, and that the position of the thinnest segment along the fiber significantly affects the simulation results. Under dynamic conditions, an irregular fiber does not necessarily break at the thinnest segment, which is different from the quasi‐static results. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2855–2861, 2004     

抗拉强度对钨丝质量的影响

通过分析加工过程中钨丝的抗拉强度对钨丝质量的影响，提出了合理选择退火点，严格控制钨丝抗拉强度σb值等改进工艺及提高钨丝质量的具体措施。     

全介质自承式架空光缆的研制

本文提出了全介质自承式架空光缆结构参数的设计方法，并对光缆材料的选取，工艺技术的关键点进行了分析，最后给出了我们研制的全介质自承式架空光缆的测试数据。     

The effects of heat loss on the burning velocity of cellular premixed flames generated by hydrodynamic and diffusive-thermal instabilities

The effects of heat loss on the burning velocity of cellular premixed flames are investigated by two-dimensional unsteady calculations of reactive flows based on the compressible Navier-Stokes equation and on the diffusive-thermal model equation. Hydrodynamic and diffusive-thermal instabilities are taken into account as contributing to the intrinsic instability of premixed flames. A sufficiently small disturbance is superimposed on a planar flame to obtain the relation between the growth rate and the wavenumber, i.e., the dispersion relation. As the heat loss becomes larger, the growth rate decreases and the unstable range narrows. This is because hydrodynamic instability caused by thermal expansion weakens for nonadiabatic flames. To investigate the characteristics of cellular flames, the disturbance with the linearly most unstable wavenumber, i.e., the critical wavenumber, is superimposed. As the superimposed disturbance evolves, the cellular-flame front forms due to the intrinsic instability. The lateral movement of cellular flames is observed at low Lewis numbers, and the behavior of cellular-flame fronts becomes more unstable for nonadiabatic flames. As the heat-loss parameter increases, the burning velocity of a cellular flame normalized by that of a planar flame increases at Lewis numbers lower than unity. By contrast, when the Lewis number is not less than unity, the burning-velocity increment decreases by increasing the heat loss. Diffusive-thermal instability thus has a pronounced influence on the unstable behavior and burning velocity of nonadiabatic cellular flames.     

Structural Instability and Microstructural Change of La3+-Doped M-Type Calcium Ferrite

Several compositions were selected to investigate the formation of M phase. It was found that by reducing Fe₂O₃ or increasing La₂O₃, we were able to obtain pure M phase, as deduced from X-ray patterns, but CaO.2Fe₂O₃ was always observed in micrographs of the polished surfaces. The instability of the M phases might be due to the distortion of the lattice structure. The development of humps in the microstructures was related to the distribution of La³⁺. Retardation in the formation of M phase when sintered in O₂ could be interpreted by the defect equation.     

温度对Fe3Al合金抗拉性能影响的研究

研究了Ｆｅ３Ａｌ合金从室温到１２００℃的抗拉性能，用扫描电观察口并对脆韬转变进行了分析。结果表明，由于水汽环境的影响，Ｆｅ３Ａｌ使金的抗性能温度的变化，不是连续地升高或下降。     

The strength, elongation and toughness of fresh and weathered bituminous roofing membranes

The author describes in detail, complete with diagrams and test data, the procedures adopted and results obtained. The main problem involving the elongation of the membranes is the large difference between the elongation of the polyester-fibre-based modified bituminous membranes, and the elongation of the glass-fibre-based oxidized bitumen membranes.