Schwingfestigkeit von Schraube‐Mutter‐Verbindungen

High cycle fatigue of bolted connections Extensive tests regarding the influences on the fatigue of bolt‐nut‐connections of preloading with torsion, of preloading with yielding, of loading with superimposed bending and of the tested lot are processed. These influences are not yet known according to VDI 2230. New testing devices were designed for these tests, which allow a far less expensive operation and may easily be used for bolts of diameters up to M100 and testing frequencies up to 1000 Hz. The validity of fatigue resistance according to VDI 2230 is specified with respect to the test results. The determined influence of the tested lots is unexpectedly high. The manufacturing process of bolts should be improved to minimize this influence.     

用于数控设备的弹性环联轴器

介绍了一种适用于数控设备改造的无键联轴器，从其原理、设计、加工各方面作了阐述，并且总结了许 多实际应用经验和适用参数。     

Multi-Scale Dilated Convolutional Neural Network for Hyperspectral Image Classification

基于多尺度空洞卷积神经网络的高光谱图像分类

郑姗姗¹,刘文¹,单锐¹,赵静一²,江国乾³,张智⁴

（1. 燕山大学理学院,河北 秦皇岛 066004;2. 燕山大学机械工程学院,河北 秦皇岛 066004;3. 燕山大学电气工程学院,河北 秦皇岛 066004;4. 北京航天研究所,北京 100094）

创新点说明：

1）将图像分割方法——空洞卷积用于卷积神经网络进行高光谱图像分类,提取更加广泛、抽象的图像特征。

2）构建基于多尺度空洞卷积神经网络的高光谱图像分类方法。搭建多尺度聚合结构,在每个通道中使用快捷连接和空洞卷积结构,有效提取图像特征,避免信息丢失。

研究目的：

针对图像信息丢失问题,得到高精度的高光谱图像分类方法。

研究方法：

在Indian Pines和Pavia University数据集上,与4个已有的高光谱图像分类方法进行对比实验,比较OA, AA和Kappa值。

研究结果：

多尺度空洞卷积神经网络在Indian Pines和Pavia University数据集上OA值分别达到了99.58%,99.92%。AA值分别达到了99.57%,99.90%。Kappa分别达到了99.52%,99.89%。

结论：

1）在卷积神经网络中引入空洞卷积,可以有效避免图像信息丢失。

2）多尺度空洞卷积神经网络能提取更佳的判别性特征,实现高分类性能。

关键词：多尺度聚合;空洞卷积;高光谱图像分类;快捷连接

     

钢管塔架K型加肋节点的承载力分析

通过试验对1／4加肋K型钢管插板连接节点的极限承载力进行了研究,同时借助有限元分析了主管壁厚,环板宽度和厚度以及不同加肋方式对节点极限承载力的影响。在此基础上根据试验和有限元结果以及节点的破坏模式提出了适用于估算此类节点极限承载力的极限分析模型和建议公式。结果表明：加肋K型钢管插板连接节点的承载力受主管壁厚和环板宽度和厚度的影响较大,且分主管控制和环板控制2种情况来讨论。采用的四铰破坏机理和五铰破坏机理极限分析模型能较好的反映此类节点的受力性能。     

计算机多级网络控制技术

介绍在西门子 Win CC视窗过程控制中心操作平台上集中多种网络通信技术的应用 ,多级网络控制系统由以太网 (TCP/IP协议 )、工业以太网 (SINEC H1协议 )、现场总线 (PROFIBUS协议 )、点到点链 RS42 2 (3 964 R系列 RK5 1 2 -方式 )组成     

PLC内部资源开发的探讨

利用PLC内部富余资源 ,实现对PLC外部输入控制电器的短路和开路故障检测。探讨了设计思路 ,给出了实际控制电器短路和开路故障的检测梯形图     

Evaluating increasing block tariff pricing policies when applied to multiple household connections

This paper develops a model for evaluating the consequences of increasing block tariff pricing policies when multiple households share a connection and applies it to a sample from Kumasi, Ghana. Results show that for any given consumption, a household's average share of total monthly water bill for shared connections can either be higher or lower than its single-household equivalent. Significant differences between the average and single-household equivalent bills were found in these cases, although this difference is under-estimated if the sample is not disaggregated by payment group.     

Strengthening steel joint of architectural structure under loading condition

Through the comparative analysis of steel plate reinforced,ceramics reinforced and non-reinforced joints under loading condition,the feasibility of strengthening steel joint of architectural structure was studied.By using element birth and death technology simulation of the fi nite element software ANSYS,it is found that when the reinforced structure is 10 mm in thickness and using steel structure to reinforce the concerned areas,the equivalent stress in concerned regionals reduces by 31.1% compared with that when the structure is not reinforced.When reinforced with ceramics,the equivalent stress in concerned regionals reduces by 24.1% compared with that reinforced with steels;when the reinforced structure is 20 mm in thickness using steels to reinforce the concerned area,the equivalent stress in concerned regionals reduces by 39.4% compared with that when the structure is not reinforced.When using ceramics to reinforce the concerned areas,the equivalent stress only decreases by 3.7% compared with that reinforced with steels.     

双腹板、顶底角钢半刚性连接节点的非线性有限元分析

用ANSYS有限元程序对双腹板、顶底角钢半刚性连接节点的非线性性能进行了理论分析,并将计算结果与试验结果进行了比较,两者吻合较好.通过对7个系列共23个双腹板、顶底角钢连接试件的有限元分析,重点探讨了连接的各类组件对节点力学性能的影响.结果表明:梁截面高度、顶底角钢厚度及与柱翼缘相连的顶底角钢螺栓间距对节点力学性能的影响较大;腹板角钢厚度对节点力学性能有一定的影响;柱腹板水平加劲肋、柱截面高度和螺栓直径对节点力学性能的影响较小.双腹板、顶底角钢连接梁柱节点属于典型的半刚性连接节点,建议在设计中考虑其对结构受力性能的影响.