Effect of gusset connection configurations on frame–gusset interaction in steel buckling‐restrained braced frame

Although buckling restrained braces (BRBs) are commonly applied in seismic buildings to mitigate structural damage, their performance was often limited by rupture of the corner gusset connections due to additional frame action. This issue may be resolved by alternative gusset connections to mitigate the frame–gusset interaction. In this study, commonly used procedures for design of the traditional gusset connection are reviewed, followed by a case study on the effect of frame action on the structural behavior of these gusset connections in steel frames with BRBs. Inspired by these analysis, two different strategies, aiming at releasing frame–gusset shear interaction using sliding gusset connection or reducing normal interaction using dual gusset plates, are tried to mitigate the frame action effects. Finite element analysis is conducted on steel frame subassemblages with/without BRBs to examine the effect of different gusset connections on the structural behavior of these framing systems. It shows that the sliding gusset connection shows beneficial effect in reducing the frame action, having much smaller stress responses on the gusset interfaces, as well as smaller shear force and plastic responses on the framing system. Thus, it becomes a promising gusset connection for improved seismic performance of the steel framing system with brace‐type dampers.     

交流弧焊机初级串接电容对空载性能的影响

论述并分析了交流弧焊机初级串接电容后对焊机空裁状态各性能参数的影响,通过实验证实了理论分析是正确的。对于交流弧焊机的应用有实际的指导意义。     

微机控制等离子喷焊设备的研制

本文介绍了用MCS-51单片机对等离子喷焊设备的工艺程序控制和对转移弧电流的闭环实时调节。简述了等离子喷焊设备的技术要求和基本组成,及所研制的等离子喷焊弧长调节器的调节原理。     

探空温湿压系统研制

介绍了用于测量大气湿度、温度和气压探空集成传感器系统.利用集成温湿压传感器采集信号,测量采用24位AD精度MCU,借助CC1000将信号调制,MAX2235将信号功率放大无线发送.给出了集成温湿压传感器结构、测量系统的原理、测量系统的硬件框图及关键软件的设计流程.实验结果证明该系统在满足测量精度的条件下,降低了系统的体积和成本.     

An approach for pattern recognition of hand activities based on EEG and Fuzzy neural network

Electroencephalography (EEG) is another interesting bio-electrical signal to differ from EMG (Electromyography). In order to pursue its application in the control of the multi-fingered robot hand or the prosthetic hand, the pattern recognition technology of the human hand activities based on EEG should be investigated as a very important and elementary research objective at first. After discussing our research strategy about EEG applied in the control of the robot hand, the recognition model named as Fuzzy Neural Network (FNN) is set up in this paper, and then its related algorithms, such as the fundamental knowledge produced, the learning samples set, the features extracted, and the patterns recognized with the artificial neural network (ANN), are deeply discussed for achieving the classification of some basic mental tasks. In addition, the experimental research has also been done using a two-channel system of measuring EEG signal, and the result shows the new recognition model using FNN can extract not only the effective spectral features of the hand movements and the other usual accompanying mental tasks, such as blinking eyes, watching red color and listening music, so as to achieve the fundamental knowledge production and the feature extraction, but also has the good capability of the pattern recognition about the human hand activities through the fuzzy setting of the learning samples and the training of its ANN.     

种植屋面用耐根穿刺防水涂料检测技术研究

从应用性能和耐根穿刺性能两方面研究了耐根穿刺防水涂料的检测技术:应用性能方面除耐霉菌性能外,还根据防水涂料分层多次涂刷或喷涂、可连续施工的特点,制定了涂层间剥离强度试验方法;耐根穿刺性能检测方法研究中,新增了潮湿层的种类,重点介绍了内衬箱的制作方法,从内衬箱选材和构造、涂层厚度和质量多个方面进行控制,确保种植箱制备成功。通过该研究,完善了耐根穿刺防水涂料性能的检测方法,为各检验机构和生产企业开展耐根穿刺防水涂料性能检测提供参考。     

亦庄线地下车站出入口设计随想

结合创作实践,通过分析、研究目前国内外地铁站出入口建设的现状,认为地铁出入口建筑不应仅重视其外观的塑造和功能的满足,并通过北京市轨道交通亦庄线工程地铁出入口的设计,提出了若干人文、人本的设计手法与理念,同时也解决了地铁出入口易识别性和与城市景观相协调的问题。     

预制混凝土夹芯保温墙桁架连接件抗剪性能研究

桁架连接件是连接混凝土夹芯墙板内外叶墙板的重要构件。为了研究桁架连接件的抗剪性能,对2组不同保温层厚度的4个受剪试件进行了试验研究和有限元分析。试验研究表明：剪力作用下夹芯墙桁架连接件的破坏形式为其腹杆受压屈曲后受拉腹杆断裂或受拉腹杆被拔出的锚固破坏。在试验的基础上,对夹芯墙体桁架连接件抗剪性能做了变参数数值分析,主要考虑了桁架腹杆直径、节点间距和保温层厚度等参数的变化。模拟结果表明：夹芯墙的屈服和极限承载力随着腹杆直径的增大而增加,随着节点间距的减小而增大;随着保温层厚度的减小,墙体的抗剪屈服承载力增大,而由于保温板的高压缩性,导致其极限荷载与保温层厚度的相关性不明显。     

Evaluating leakages through GMB/GCL composite liners considering random hole distributions in wrinkle networks

This paper presents a study on the development of a hydraulic connectivity analysis-based approach for evaluating leakage rates through geomembrane (GMB)-geosynthetic clay liner (GCL) composite liners considering random hole distributions in a GMB wrinkle network. An algorithm for hydraulic connectivity analysis was developed to find the hydraulically connected wrinkles from a wrinkle network, and an explicitly expressed criterion is proposed to define the hydraulic connection between wrinkles under the assumption that only one of the two adjacent wrinkles is possible to be damaged. A Monte Carlo simulation was used to evaluate the probability weighted average of the total leakage through multiple randomly distributed holes considering numerous possible combinations of locations of holes. The proposed approach was applied to typical examples reported in the literature and shows that it can objectively quantify the effect of the hydraulic properties of the liner and overburden pressure on the hydraulic connectivity between wrinkles in a wrinkle network. The proposed approach also allowed assessing the effect of different probabilities of various hole distributions on the calculated leakage, which was demonstrated to be non-negligible, especially when the hole frequency is small.