电网设备线夹开裂原因

某电力公司变电站用铝合金设备线夹在运行过程发生批次开裂事故,通过宏观观察、断口分析、化学成分分析、力学性能测试、冷冻模拟试验等方法,对设备线夹的开裂原因和开裂机理进行了分析。结果表明:设备线夹焊缝存在焊接缺陷,导致焊缝强度下降;设备线夹接线管底部存在积水空间,寒冷天气下积水结冰,体积膨胀,使焊缝承受设计工况外的负载而过载开裂,造成了线夹开裂。     

水下连接器毂座加工工艺研究

针对水下连接器典型工件毂座的加工难点,通过研究其结构特点与材料特性,制定了工艺路线,并通过工艺试验,研究了抑制颤振和自适应插补在复杂型面数控加工中实现技术,确定了关键工序的工艺参数,满足了水下连接器毂座的加工精度和使用性能要求,也为类似结构加工制造提供借鉴。     

Synthesis of Zn0·1Cd0·9S heterostructure with N-doped graphene quantum dots and graphene for enhancing photoelectric performance in UV–visible light

In the present study, a heterostructure based on Zn_0·1Cd_0·9S, N-doped graphene quantum dots (N-GQDs), and graphene was successfully prepared by a simple method. Various analyses are conducted to determine the structure, morphology, and materials performance of the synthesized composite. The results exhibit that the Zn_0·1Cd_0·9S/N-GQDs/graphene heterostructure presents excellent photoelectric performance with a high photocurrent of 4.43 × 10⁻⁵ A/cm² and 3.43 × 10⁻⁵ A/cm² under light irradiation of 365 nm and 405 nm, respectively. It demonstrates a two-fold photocurrent enhancement in comparison to blank Zn_0·1Cd_0.9S. This remarkable improvement is ascribed to a mechanism in which the N-GQDs act as photosensitizers, enhancing the absorption ability. Concurrently, graphene serves as a carrier mobility substrate, facilitating the separation of the photogenerated electron–hole pairs. The synergetic effect between Zn_0·1Cd_0·9S, the N-GQDs, and graphene enhances the photoelectric performance. The Zn_0·1Cd_0·9S/N-GQDs/graphene heterostructure provides a new route for the enhancement of the photoelectric performance of a semiconductor under UV–visible light.     

群钉连接件在桥梁工程中的应用

介绍了群钉连接件的国内外研究状况,阐述了群钉连接件在桁架组合桥、连续组合箱梁桥、大跨度斜拉桥桥塔等桥梁工程中的使用情况,并总结了群钉连接件的优点,以进一步推广群钉连接件的广泛应用。     

组合桁架中节点板上升式连接件有限元分析模型

为了探讨组合桁架中节点板上升式连接件内应力应变分布规律及其受力机理，本文先对整体测试的组合桁架中这类连接件进行受力分析，然后建立有限元模型，编制ＦＯＲＴＲＡＮ程序，计算出一系列应力，以便于后文中与实测值比较分析。     

地铁车站地下连续墙钢筋接驳器安装工艺的改进

地下连续墙的钢筋接驳器就是在地下连续墙钢筋施工的同时,根据以后地下结构楼板的标高要求,为以后地下连续墙和楼板整体连接而预埋在地下连续墙钢筋笼上的接驳件,接驳器的形式为钢管内螺纹式。在苏州地铁星湖街站的施工中,通过对接驳器施工的质量现状的调查和分析,提出了一种改进接驳器施工质量的方法——"定位卡"及"封盖板",现场试验的效果表明,改进工艺后克服了接驳器定位偏差和丝牙破坏、锈蚀等弊病。     

Large-scale test of symmetric cold-formed steel (CFS)-concrete composite beams with BTTST enhancement

A new connection device, based on bent-up tab shear transfer enhancement called bent-up triangular tab shear transfer (BTTST), has been studied through a symmetric cold-formed steel (CFS)-concrete composite beam subjected to a static bending test. BTTST provides an alternative connector system unique to CFS where CFS sections are usually thinner than hot-rolled sections and welding of headed-stud shear connectors is inapplicable. Coupled with the back-to-back arrangement of two CFS channels where symmetricity of the built-up section is restored, the resulting composite floor system has been proven to possess adequate strength and stiffness properties under static loads. The work has shown that the predicted values of the flexural capacities calculated using a new equation of shear capacity of BTTST agrees reasonably well with the experimental values.     

体内预应力组合梁混凝土预压应力分析

针对在混凝土翼板中设置后张预应力的连续组合梁,提出由分担预加轴力、主弯矩和次弯矩产生的混凝土法向应力计算公式,主要分析施加于混凝土翼板的预应力通过剪力键向钢梁传递的力学模型,建立混凝土翼板承担的预压力沿梁纵轴的分布函数和理论解,求得考虑剪力键柔性的混凝土法向应力计算公式,作为组合梁抗裂设计依据。     

设置碟形弹簧的框架-摇摆墙结构抗震性能试验研究

受控摇摆墙通常采用预应力筋的形式实现，预应力筋基础锚固施工困难，墙体摇摆幅度很小且易与基础发生碰撞。为解决上述问题，研发了一种受控摇摆墙，主要通过基于碟形弹簧的装置实现墙体的受控约束，墙体与主体框架、基础分别采用耗能连接件和V形支撑连接。设计制作了缩尺比为1∶2的对比框架与框架-摇摆墙试件，通过低周往复加载试验研究其抗震性能、破坏模式和自复位特性。结果表明，设置碟形弹簧的框架-摇摆墙较对比框架承载力提高了107.1%，且具有更好的刚度退化性能与耗能性能，框架结构的变形模式得到改善，使得各层的层间位移趋于均匀。连接件是影响框架-摇摆墙结构耗能及协调层间变形的关键，应进一步研究其改进措施及优化设计。     

板片空间结构体系连接设计方法研究

板片空间结构体系中板片与骨架或板片之间是由有限个点连接的 ,连接点之间的板杆间存在缝隙。将点对接触算法用于该体系的板杆共同工作分析 ,该算法模型能很好地反映该体系的实际工作状态 ,用于板片空间结构连接设计分析能够取得良好的效果 ,并可作为该体系连接设计简化方法的理论依据