精密挤压(拔制)圆角方型材等相似成形模具映射建模优化

本文针对亟待实现的挤压 (拔制 )异型材模具精密快速加工设计理论课题 ,借助于近代共形映射理论研究成果 ,求解了异型材挤压 (拔制 )模具相似成形塑性流动的数学模型 ,建立了圆角方型材精密挤压 (拔制 )模具模腔数学模型及其优化函数方程 ,建立了为实现模腔精密快速的CAD/CAM一体化的理论模型     

Special-shaped tube drawing forming and conformal optimization of die cavity

Aiming at the issues in quick processing and modeling design of drawing special-shaped tube die, by Conformal Mapping Theory and the numerical trigonometry method of interpolation between odd points and even points, the conformal mapping function is obtained. As the result, three-dimension drawing forming were converted into that of two-dimension problems, and the plastic stream function was analyzed, die cavity modeling and its optimized function were set up. Combining with modern processing technology, NC program and CAM of die cavity can be realized. Taking the drawing forming of hexagon tube with arc radii r and ellipse-shaped tube as instances, the drawing die cavity optimization of special-shaped tube was achieved, as well as, the changing principle of wall thickness was analyzed.     

椭圆异型材挤压及模腔共形优化

针对金属椭圆异型挤压塑性成型及模腔优化的理论课题，应用复变共形映射数学研究成果，利用奇偶点相互迭代的三角插值法和法线收敛法，将三维金属异型材挤压塑性成型问题转化为二维轴对称成型问题，求解异型挤压模腔曲面函数，建立映射函数解析方法，推导椭圆异型材挤压金属塑性成型连续流动场和应变速度场的数学解析式，并应用金属塑性成型能量板值原理，进行异型材挤压模腔参数的优化，同时为精密快速地实现挤压模腔的CAD／CAM一体化目标提供技术支持。     

基于简支弹性矩形板含集中质量振动基波频率共形映射解析

借助共形映射理论,采用矩形板边界域奇偶插值点两序列的三角插值方法,寻求了带圆角矩形板等复杂域与单位圆域的共形映射函数;针对含有集中质量振动简支弹性异型板基波频率值的求解,在平面常应力状态下,完成该复杂弹性板以单位圆域方法描述的振动方程,求解板基波频率系数。以带圆角矩形简支板域求解为示例,分析了集中质量大小与位置、矩形长宽比值e、平面常应力系数Sp对基波频率的影响。     

Mapping analysis of vibrating fundamenta frequency for simple-supported elastic rectangle-plates with coneentrated mass

By conformal mapping theory, a trigonometric interpolation method between odd and even sequences in rectangle boundary region was provided, and the conformal mapping function of rectangle-plate with arc radius between complicated region and unite dish region was carried out. Aiming at calculating the vibrating fundamental frequency of special-shaped, elastic simple-supported rectangle-plates, in the in-plane state of constant stress, the vibration function of this complicated plate was depicted by unit dish region. The coefficient of ftmdamental frequency was calculated. Whilst, taking simple-supported elastic rectangle-plates with arc radius as an example, the effects on fundamental frequency caused by the concentrated mass and position, the ratio of the length to width of rectangle, as well as the coefficient of constant in-plane stress were analyzed respectively.     

椭圆异型挤压塑性成形映射理论及模腔优化解析

针对金属椭圆异型挤压塑性成形及模腔优化的理论课题,应用复变共形映射数学研究成果,利用奇偶点相互迭代的三角插值法和法线收敛法,将三维金属异型挤压塑性成形问题转化为二维轴对称成形问题,求解异型挤压模腔曲面函数,建立映射函数解析方法,推导椭圆异型材挤压金属塑性成形连续流动场和应变速度场的数学解析式,并应用金属塑性成形能量极值原理,进行异型材挤压模腔参数的优化,同时为精密快速地实现挤压模腔的CAD/CAM一体化目标提供技术支持。     

椭圆异型挤压塑性成形及模腔映射优化

针对非轴对称金属异型挤压塑性流动及模腔研究的理论课题,借助于近代共形映射数学理论研究成果,利用法线收敛法,建立了映射函数解析方法。将三维金属异型材挤压塑性成形问题转化为二维轴对称成形问题,求解椭圆异型挤压金属塑性成形连续流动场和应变速度场的数学解析模型,并应用金属塑性成形理论,建立了精密挤压异型材优化模腔的数学模型,同时为精密快速地实现挤压模腔的CAD／CAM一体化目标提供了技术支持。     

精密挤压金属方型材相似成形与模具映射优化研究

针对圆角方型材精密挤压金属塑性流动描述及相似模具几何参数优化的焦点问题 ,借助于复变共形映射理论 ,建立了表达塑性流动的数学模型及其模具参数 ,塑性体的能量方程 ,实现了模具参数优化及几何解析函数的建立     

Automatic testing system design and data analysis of permafrost temperature in Qinghai-Tibet Railway

Aimed at the characteristics of permafrost temperature influencing the safety of Qinghai-Tibet Railway and its on-line testing system, comparing the achievement of permafrost study nationwide with those worldwide, an automatic testing system of permafrost temperature, containing a master computer and some slave computers, was designed. By choosing high-precise thermistors as temperature sensor, designing and positioning the depth and interval of testing sections, testing, keeping and sending permafrost temperature data at time over slave computers, and receiving, processing and analyzing the data of collecting permafrost temperature over master computer, the change of the permafrost temperature can be described and analyzed, which can provide information for permafrost railway engineering design. Moreover, by taking permafrost temperature testing in a certain section of Qinghai-Tibet Railway as an instance, the collected data of permafrost temperature were analyzed, and the effect of permafrost behavior was depicted under the railway, as well as, a BP model was set up to predict the permafrost characteristics. This testing system will provide information timely about the change of the permafrost to support the safety operation in Qinghai-Tibet Railway.     

Mapping analysis of vibrating fundamental frequency for simple-supported elastic rectangle-plates with concentrated mass

By conformal mapping theory, a trigonometric interpolation method between odd and even sequences in rectangle boundary region was provided, and the conformal mapping function of rectangle-plate with arc radius between complicated region and unite dish region was carried out. Aiming at calculating the vibrating fundamental frequency of special-shaped, elastic simple-supported rectangle-plates, in the in-plane state of constant stress, the vibration function of this complicated plate was depicted by unit dish region. The coefficient of fundamental frequency was calculated. Whilst, taking simple-supported elastic rectangle-plates with arc radius as an example, the effects on fundamental frequency caused by the concentrated mass and position, the ratio of the length to width of rectangle, as well as the coefficient of constant in-plane stress were analyzed respectively.