Estimation of a joint diameter distribution by an implicit scheme and interpolation technique

A new technique to estimate the diameter distribution of a joint set from the contained trace length distribution is suggested. This technique obtains the diameter distribution directly from the sample histogram of the contained trace lengths without using any information about the trace length distribution of an infinite window. Compared with the previous method of Song and Lee [Estimation of joint length distribution using window sampling. Int J Rock Mech Mining Sci 2001; 38: 519–28], it is more accurate for small-size joint samples. To obtain more accurate estimates, we adopt an interpolation technique of B-spline to smooth out the sampled contained trace length distribution. The effect of the B-spline as a function of three kinds of predefined diameter distributions is examined by Monte Carlo simulations.     

Networked Product＇s Cooperative Design and Manufacturing Based on Top Basic Skeleton Model

This paper discusses the top-down design flow. An ifinovative theory and method, Top Basic Skeleton （TBS） model, is put forward, which supports cooperative design. The principle, the function of the TBS and its application are detailedly explicated on the cooperative design by the design examples.     

伸张区宽度和韧窝直径与常规力学性能之间的关系

研究了伸张区宽度(I)和韧窝直径(P)与常规力学性能之间的关系.研究结果表明,l与σ_y/(1 n)之间、D与(S_F-σ_b)/S_F之间均呈现出良好的线性相关关系.这可从伸张区和韧窝形成过程与各阶段塑性变形的关系中得到解释.     

650轧钢车间出炉辊道的改进

针对６５０轧钢车间出炉辊道在使用过程中出现的问题进行了改进，提高使用寿命１～２倍，经济效益十分显著。     

Hierarchical Ring Network design

A Hierarchical Ring Network is obtained from a ring network by appending at most one subsidiary ring to each node of the ring and, recursively, to each node of each subsidiary ring. The depth d is the number of levels of the recursive appending of subsidiary rings. There are different definitions according to which rings are appended to nodes created at the preceding level (called an HRN) or to any node (called here an HBN for Hierarchical Bubble Network). The case of an HRN was considered by Aiello et al. who give bounds (not tight) on the diameter of such an HRN as a function of the depth and the number of nodes. Here we determine the exact order of the diameter both for an HRN and an HBN. In fact we consider the optimization problem of maximizing the number of nodes of an HBN (or an HRN) of given depth d and diameter D. We reduce the problem to a system of equations with a complex objective function. Solving this system enables us to determine precisely the structure of an optimal HBN and to show that the maximum number of nodes is of order D ^d /d!.     

斜拉跨越结构的优化分析

考虑斜拉索直径、塔架高度和斜拉索与塔架连接间距三方面因素,利用有限元法对斜拉跨越的结构形式进行优化分析。结果表明,斜拉索的尺寸变化对结构的强度影响不大,而对结构的变形影响很大,其中斜拉索的直径以从管架桥中间到两边逐渐减小的分布形式最好。塔架高度变化对结构的变形影响不大,而对结构的强度影响很大,塔架高度为46m时结构的强度更好。斜拉索与塔架的连接间距变化对结构的变形影响很小,而对结构强度影响很大,当间距为7.5×10-2 m时结构的强度更好。     

凝汽器软胶球直径对收球率的影响分析

为了了解胶球直径和收球率的内在联系,对胶球进行受力分析,得到保证胶球顺利通过换热管需要的压力差△P的计算公式,设计了验证实验台,验证了该公式并对其进行了改进.结果表明：要使胶球能顺利通过换热管,保证系统收球率,则必须满足该公式计算得到的最小△P值.     

基于IMAQ的小孔径测量

利用IMAQ的逼近法寻找圆周边缘可以实现孔径检测，但是对于小孔径测量是无效的。采用圆弧定圆心法和微圆填充法，用于小孔径的尺寸测量；通过尺寸校正系数获得测量值。实验结果表明，利用数字图像处理技术对零件孔径进行检测，是一种有效的方法。     

顶帆和顶舵雷达天线转台仿真系统研制中的有关问题

在《顶帆和顶舵雷达天线转台系统仿真设计中的若干问题》一文的基础上,对天线系统的最大回转半径、天线转台仿真系统与舰船桅杆基座的联接方式、顶帆雷达天线与方位转台的联接方式以及顶帆雷达球形支座的展开图作了分析,提出系统研制中需要注意的一些问题。     

运用均衡凝固理论设计液压机上横梁底雨淋式浇注系统

400 t液压机上横梁,材质HT200,铸件重4 670 kg,主要壁厚55 mm,轮廓尺寸1 818 mm×1 262 mm×730 mm,普通粘土砂手工造型,干型、干芯。运用大孔出流理论设计底雨淋式浇注系统,直浇道直径φ85 mm,位于55/65 mm×52 mm横浇道中间,两侧横浇道上均布12 mm×60 mm、长40 mm底雨淋内浇道共14只。用均衡凝固收缩模数法核算浇注系统当冒口的补缩能力。生产结果表明,铸件没有气孔、夹砂、夹渣、收缩等铸造缺陷,铸件品质稳定。实测浇注时间平均92 s,与计算值偏差1%,工艺出品率94%。生产实践证明,采用大孔出流理论设计浇注系统,用均衡凝固收缩模数法校核浇注系统的补缩功能,可以满足铸件充型和补缩要求,具有实用价值。