混杂纤维混凝土锚固伸缩缝结构承压性能研究

桥梁伸缩缝处在桥梁薄弱部位,存在长期受车辆局部荷载作用下的严重受损问题,其力学性能需得到改善。试验采用不同的伸缩缝区锚固材料以及不同类型的型钢单缝装置在局部受压试验下,研究不同伸缩缝锚固材料与不同种类的型钢单缝装置下伸缩缝结构的受力性能。结果表明,相比于素混凝土试件,混杂纤维混凝土伸缩缝试件的强度和延性有明显的提升;同时采用E型钢单缝装置和晶须混凝土试件的性能也均有所提高。这些结论已为目前工程的伸缩缝结构设计提供依据,也将为后续伸缩缝结构局部受压损伤机理的深入研究提供参考。     

玻璃熔窑的膨胀缝处理方法

膨胀缝是玻璃熔窑很重要的一种结构形式.介绍了玻璃熔窑膨胀缝的几种形式、标注方法、膨胀缝的留设原则、技术要求和施工注意事项等,并简要分析了玻璃熔窑各个不同部位膨胀缝的处理方法及其利弊.     

公路桥梁梳形板伸缩缝施工技术

文章基于实际的高速公路桥梁案例,分析梳形板伸缩缝施工技术在工程中的应用,首先介绍该项目工程的基本概况,然后在测量放线、切缝施工、伸缩缝吊装施工等方面研究梳形板伸缩缝的施工要点,通过研究可知梳形板伸缩缝施工技术的广泛应用可以提升公路桥梁的施工质量,这也为我国公路桥梁的建设作出了巨大的贡献。     

新型抗冲击纤维混凝土桥梁伸缩缝健康监测研究

以赣粤高速公路新建桥梁伸缩缝为对象,采用新型抗冲击纤维混凝土作为灌缝材料替代原设计采用的素混凝土,并通过在灌缝材料中埋设长标距光纤传感器的健康监测手段,定量评价新型抗冲击纤维混凝土对桥梁伸缩缝长期性能的改善效果。结果表明,通过在灌缝混凝土中埋设长标距光纤传感器,可以实现对伸缩缝灌缝混凝土损伤的长期跟踪监测;从监测数据分析可知,采用不同配比的新型抗冲击纤维混凝土,对伸缩缝长期性能均有明显提升,采用新型抗冲击纤维混凝土的灌封区混凝土开裂应变较素混凝土平均增加约100με。     

钢筋混凝土水池伸缩缝漏水原因分析及处理措施

大型水池设置伸缩缝时，由于伸缩缝处钢筋较密、止水带难以固定等原因，伸缩缝漏水现象经常发生。对某消防水池伸缩缝漏水的原因进行了分析，分别就新加背贴式止水带和取消伸缩缝2种处理方法的优缺点进行了对比，最终选择了取消伸缩缝连续浇筑膨胀加强带的处理方法。经过1 a多的运行，伸缩缝没有再出现扩张和漏水现象。运行实践表明该方法效果良好，安全可靠。     

新型水煤浆加压气化炉耐火砖膨胀缝的优化设计

介绍了新型水煤浆加压气化炉燃烧室内衬耐火材料结构情况,分析了膨胀缝处耐火砖易损的原因。根据向火面砖的膨胀量、灰缝压缩量、炉壳膨胀量等进行计算,确定了较为合理的耐火砖的膨胀缝预留尺寸;其他膨胀缝填有陶瓷纸、可压塑材料、纤维填充材料等,可以有效缓冲热应力带来的耐火材料的膨胀。优化后,膨胀缝处耐火砖使用良好,无异常现象发生,为气化炉的长周期稳定运行打下了基础,也为整个生产系统的稳定、效益运行提供了有利保障。     

多喷嘴对置式气化炉拱脚膨胀缝耐火砖改造

针对耐火衬里膨胀缝不能单独拆卸更换,导致拱顶砖与膨胀缝耐火砖运行、检修周期不匹配,给检修运行造成了极大的隐患及维修费用浪费的问题,提出了膨胀缝耐火砖型、衬里砌筑结构、膨胀缝尺寸调整的整套改造方案。解决了上膨胀缝砖不能单独拆卸砌筑的问题,达到了消除检修及运行瓶颈,提高运行周期、稳定性及备车率的目的,为最终实现耐火衬里根据运行周期分段检修更换,充分挖掘耐火砖运行潜力,节能降耗,提高气化炉运行效率奠定基础。     

桥梁伸缩缝损坏原因及改进

随着我国交通运输事业的飞速发展,高速公路、高架道路、立交桥的大量兴建,桥梁车辆通行量的增大,车速的提高,橡胶行业为其配套的桥梁伸缩缝在桥梁建设中的地位越来越显得举足轻重。其耐久性、防水性和行车性能日益受到重视,产品更新很快,但伸缩缝的损坏也很普遍,有必要对其损坏的原因进行分析,提出设计施工改进建议,延长使用寿命。常用伸缩缝中板式橡胶伸缩缝及ＢＦ伸缩缝是使用最多、最广泛的,但损坏也比较严重,一年就发现有部分损坏现象,５年后就大部分损坏。一种配衬密封橡胶条的毛勒型钢缝是近几年来得到大范围推广使用的产…     

BEJ型伸缩缝应用效果显著

为解决高等级公路车流量大,车速快,载重车辆多,巨大的冲击力使桥梁橡胶伸缩缝破损、脱落、松动的问题,选用ＢＥＪ型伸缩缝进行更换效果显著。ＢＥＪ型伸缩缝是由两条钢梁嵌装橡胶条组成的机械系统,用一种被称为“ＢＹｉｔｆｌｅｘ”的树脂混合物将伸缩缝桥梁粘结起来...     

伸缩缝施工技术在市政道路施工中的探讨

由于我国道路施工频繁出现问题,很多施工承包单位投入了大量资金来研究施工技术,伸缩缝施工技术便是其中的一种。为了提高该项技术的施工质量,本文以市政道路施工的伸缩缝施工技术作为研究对象,通过技术对比分析,选取板式橡胶伸缩缝技术作为此次研究的核心技术。将该项技术应用到实际工程中,提出施工前的准备工作,并制定了切缝、开槽、型钢安装、混凝土浇筑、养生、安装橡胶条6项施工措施。     

工艺管道热补偿的研究

热胀冷缩是自然界的基本规律。在管道设计上,必须考虑管道的热胀或者冷缩,并且采取相应的措施控制管道的热胀或者冷缩。针对工艺管道的热胀现象,研究工艺管道的热补偿,提出管道热伸长的计算,着重介绍波纹管补偿器及选用程序。     

Contraction stress build‐up of anisotropic conductive films (ACFs) for flip‐chip interconnection: Effect of thermal and mechanical properties of ACFs

The important mechanical mechanism for the electrical conduction of anisotropic conductive films (ACFs) is the joint clamping force after the curing and cooling processes of ACFs. In this study, the mechanism of shrinkage and contraction stress and the relationship between these mechanisms and the thermomechanical properties of ACFs were investigated in detail. Both thickness shrinkages and modulus changes of four kinds of ACFs with different thermomechanical properties were experimentally investigated with thermomechanical and dynamic mechanical analysis. Based on the incremental approach to linear elasticity, contraction stresses of ACFs developed along the thickness direction were estimated. Contraction stresses in ACFs were found to be significantly developed by the cooling process from the glass‐transition temperature to room temperature. Moreover, electrical characteristics of ACF contact during the cooling process indicate that the electrical conduction of ACF joint is robustly maintained by substantial contraction stress below T_g. The increasing rate of contraction stresses below T_g was strongly dependent on both thermal expansion coefficient (CTE) and elastic modulus (E) of ACFs. A linear relationship between the experimental increasing rate and E × CTE reveals that the build‐up behavior of contraction stress is closely correlated with the ACF material properties: thermal expansion coefficient, glassy modulus, and T_g. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2634–2641, 2004     

高温高压固定管板式换热器膨胀节更换技术

针对加氢预热器膨胀节失效的问题,简要的介绍修复该固定管板式换热器膨胀节所采用的方法,同时还按相关标准校核了膨胀节焊缝的强度,指出了膨胀节拆装的主要注意事项。     

塑料制品压配联接设计

从生产实际出发 ,介绍了典型压配联接的原理以及设计应力、压出力、径向过盈量和热膨胀的计算方法。对压配联接的长期性能和温度变化的影响应该加以考虑 ,尤其对轴和毂材料不同时的压配联接。     

The effect of temperature dependent materials properties on fiber optic cable design

Young's Modulus and the thermal expansion coefficient are material parameters used to predict the low temperature contraction of a fiber optic cable. In the past, room temperature values for these properties were used to estimate this contraction. In this paper, these properties have been determined as functions of temperature. Using these properties, the overall expansion coefficient of the cable was determined as a function of temperature. This overall coefficient was integrated from room temperature to the low operating temperature of the cable to predict the contraction of the cable. In this way, the temperature variations in the materials properties were incorporated into the design, resulting in a more accurate determination of the low temperature contraction of fiber optic cable.     

Exploring contraction–expansion inertial microfluidic-based particle separation devices integrated with curved channels

Separation of particles or cells has various applications in biotechnology, pharmaceutical and chemical industry. Inertial cell separation, in particular, has been gaining a great attention in the recent years since it has exhibited a label-free, high-throughput and efficient performance. In this work, first, an inertial contraction–expansion array microchannel device, capable of passively separating two particles with diameters of 4 and 10 μm, was numerically studied. Then, the validated model was combined with curved geometries in order to investigate the effect of curve features on the separation process. The overall purpose was to investigate the interaction between the two different separation methods (separation with curved channels and with contraction–expansion arrays) to find an ideal model that can enjoy the merits of both contraction–expansion and curved channel based methods. Moreover, the relation between separation strength and the aspect ratio in the contraction and expansion zones of the simulated model as well as its height were examined. Then, a new model that combines the curved and the contraction–expansion geometries was tested for its efficiency. This new geometry showed that separation could be achieved with shorter lengths compared with straight contraction–expansion geometries.     

浅议金属波纹管膨胀节的力学特性、主要类型与工程应用

金属波纹管膨胀节作为管道系统中的柔性补偿元件,依靠波纹管的变形吸收或转移热位移,已在工程上得到越来越广泛的应用。分析了金属波纹管膨胀节的力学特性,压力推力的分布,为管系约束的设置及设备管口的载荷校验提供了依据;介绍了金属膨胀节的主要类型及典型应用,提出了特殊介质及负压工况管系中膨胀节设计的注意事项;最后与同样作为管道软连接的金属软管在工程选择上进行了对比。     

弹性环氧胶的特性与应用研究

叙述了一般环氧胶存在的缺陷,应用时稍有不当,伏下隐患就会造成失效。以双酚A环氧树脂为主剂,配合优质高胺值类固化剂等组成的弹性环氧胶,既保持环氧胶体系良好的胶接性能,又具有类似橡胶弹性行为的特性。其在航天产品电装工艺实施胶装、粘固、灌封中,已获得令人满意的技术结果。     

用于管板连接的液压胀管的研究与应用

换热器管与管板的传统胀接方法是机械胀接。它有许多不确定的因素和缺点。特别是应用在具有腐蚀性场合的化工设备和在不易接近的管胀接工作中。液压胀管是近10年国外发展的新方法。它具有可计算和方便控制的优点,胀管不损伤管并能应用于深孔胀接。它的成功应用可使换热器的结构产生革命性的变化。     

小通道单相流体突扩和突缩局部阻力特性

采用缝隙测压这种在通道上直接测量压力的方法，测量了内径从0.330 mm变化到0.580 mm的小通道内突然扩大和突然缩小的局部阻力特性。结果表明，缝隙测压方式是一种可行的压力测量方法;与常规通道的实验结果相比，在层流阶段，小通道内液体流动具有较小的突扩局部阻力系数以及较大的突缩局部阻力系数;而在湍流阶段，小通道内液体流动的突扩和突缩局阻系数与常规通道的实验结果相同。