后张无粘结预应力技术在公路桥上的应用实例

从无粘结预应力桥板特点及施工,介绍后张无粘结预应力技术在公路桥上的应用实例。     

粘结技术在修船中应用

随着科学技术的不断进步和发展，粘结技术的开发和应用，已经渗透到 各行各业，越来越为人们所重视。这对提高产品的质量和生产率，降低能耗都起着重要的作用。当今世界工业发达的国家，已将粘结技术广泛应用于工业和国防。近年来在船舶修造行业中，也开始为人们所广泛应用。我厂在修船中应用粘结剂的历史已达10余年。在062型艇，037型艇，登陆艇的轴、舵系，主机垫片， 螺旋桨与艉轴配合等方面采用粘结技术施工，到目前为止，从未发生过任何因粘结技术失败的事故。现针对我厂的运用情况谈谈粘结技术在修船上的应用。     

无粘结预应力技术在圆形水处理池中的应用

1前言 无粘结预应力分段张拉技术在圆形水处理池中的应用，在我国是从90年代开始的。在90年代以前，我国圆形水处理池大都采用预制壁板拼装结构，对于特殊高大的圆形水处理池则采用现浇结构．预制或现浇壁板外侧采用连续配筋方式，即用绕丝机缠绕预应力高强钢丝来施加预应力，这类绕丝预应力圆形水处理池在我国已建成300余座．遍布全国近20个省、市的50多个城市。进入90年代后．随着我国预应力技术和张拉工艺迅速发展．特别是近十年来无粘结预应力成套技术，包括无粘结预应力筋的制作、生产，     

缓粘结预应力技术在综合体建筑大跨度梁中的应用

缓粘结预应力技术是一种区别于普通预应力和无粘结预应力的新型技术,它具备后张法预应力筋中有粘结和无粘结的共同优点,且又克服了二者的缺点.文章通过介绍广州南沙国际邮轮母港综合体项目中大跨度梁缓粘结预应力的应用,阐述了缓粘结预应力技术施工工艺及特点,并对应用效果进行了详细的分析,期望能为后续类似综合体建筑大跨度梁采用缓粘结预...     

FRP筋混凝土粘结滑移有限元分析

FRP筋与混凝土间的粘结性能是FRP筋与混凝土共同工作的基础,为充分利用FRP筋强度高的优点,避免粘结破坏,必须找出FRP筋与混凝土间的粘结滑移规律。文中基于连续曲线模型,采用特殊单元模拟FRP筋与混凝土间的粘结滑移,通过有限元分析,归纳出FRP筋与混凝土间的粘结滑移规律。     

环氧树脂钢筋的粘结锚固性能

介绍国内外对环氧树脂钢筋的粘结锚固问题的研究情况及有关标准的规定，结合试验研究对现行业标准提出了补充建议，并对纤维塑料筋作了比较。     

粘结技术在轮机工程安装中的优势

本文介绍了船舶艉轴管定位安装和主机安装垫片分别采用传统安装工艺与粘结技术安装工艺的方法，通过两种不同工艺的比较，说明了粘结技术在船舶轮机工程安装中的优势。     

水泥混凝土桥梁桥面防水粘结层性能要求及对比分析

桥梁防水粘结层对延缓桥面铺装损坏和延长桥梁结构混凝土使用寿命具有十分重要的作用,是桥面铺装的重要组成部分。通过对桥面防水粘结层材料的类型和特点的分析,选择目前常用的4种防水粘结材料进行室内性能测试和现场性能验证。结果表明,采用热融沥青的结构性防水层粘结性能和剪切性能均优于涂膜类材料,而且剪切强度尤为明显,表明结构性防水层中的碎石有利于提高防水粘结层的抗剪切强度。     

预应力板在滨州龙悦国际酒店中的应用

本文主要论述无粘结预应力板在框筒结构体系中的应用，为框筒结构设计提供了一种新思路。     

塑料粘结技术在修船中的应用

本文主要介绍了白马船厂十余年来在修船中应用塑料粘结技术的具体情况,对粘结剂的配方、使用方法等也都作了详细的说明。     

船舶玻璃窗采用弹性粘接的强度近似分析与设计探讨

弹性粘接是一项较新的技术，与传统方法相比，具有较多优点。其中最显著的优点是接头具有弹性，避免应力集中，并且整个粘接面都参与接头强度的形成，因此可以简单通过增大粘接面面积来传递更大的力。该技术用于汽车玻璃窗的粘接已经有20多年的历史，但在国内造船行业应用很少。通过分析船舶玻璃窗的受力状况和采用弹性粘接时粘接层的应力状况，介绍了粘接层强度近似分析方法，并且探讨了粘接层尺寸设计原则，说明船舶玻璃窗采用粘接剂粘接是安全可靠的。     

船用胶粘剂粘接工艺

某新型常温固化船用胶粘剂粘合强度,技术指标要求≥1.5 MPa,为了实际应用该胶粘剂,研究了胶粘剂的粘接工艺。以胶粘剂粘接钢/橡胶拉伸试样为对象,研究了不同施压载荷和时间对粘合强度的影响。在固定施压载荷和时间的条件下,对单位面积胶粘剂用量与粘合强度的关系进行了研究。结果表明,在施压压力0.18 MPa、施压时间5 h条件下,将单位面积胶粘剂用量控制在(21.64～59.43)g/m2(双面),其粘合强度可满足技术指标要求。     

风电叶片用胶粘剂研究现状

本文介绍了胶粘剂在风电叶片上的应用,详细论述了风电叶片用胶粘剂必备的特殊性能,综合分析了国内外在该领域的研究进展和现状。通过对比目前市面上最主流的三种风电叶片用胶粘剂的力学性能与工艺性能,阐明了国产胶粘剂与国外同类产品的差距。     

IC封装导电银胶用片状银粉的研制

先通过液相化学还原法制备原始银粉,再利用机械球磨法制得片状银粉,对银粉的形貌、粒度分布、粉体密度、比表面积、水分灰分进行表征,研究原始粉制备工艺、球磨工艺对片状银粉形貌尺寸、粒度分布及密度的影响。结果表明,以分散性好及平均粒径约3μm的球形银粉为原始银粉、无水乙醇为介质,2 mm尺寸规格的氧化锆球为磨球,球磨时间为35 h,机械球磨法制得片状化程度高、粒径均匀、平均粒径小于7μm的片状银粉。将片状银粉用环氧树脂体系配制成IC封装导电银胶,测试导电胶固化前的物性参数、固化片的特性、固化粘接特性及环境测试,并常温下观察是否分层,均达到了应用指标要求。     

Experimental and numerical investigation of the behavior of ship windows subjected to quasi-static pressure loads

High load-carrying capacity of ship windows is important for ship safety. This aspect has recently become significant after several incidents with broken windows in superstructures had occurred. In order to get more insight into the failure behavior and into the interaction between glass windows and surrounding wall structure, experiments and numerical investigations of windows subjected to quasi-static as well as impact loads were performed. In this paper quasi-static ultimate load tests with full-scale test models, each containing a clamped or bonded laminated safety glass window, are described. Finite element modeling of the steel structure, laminated glass, and elastomer bonding or gasket is outlined in detail. Material data are based on small-scale tests of steel and glass specimens, and on published data. Afterwards a method to calculate failure probabilities of glass panes under pressure loads is presented. Failure probabilities for the glass panes in the tests are determined and failure mechanisms are clarified. Finally, hints for designing safe windows and for improving window designs are given.     

Effects of adhesive type on the mechanical properties of adhesive joints between polyurethane top coats and polyurethane-based adhesives after accelerated atmospheric ageing

The performance of a sealed stainless steel bracket system, adhesively bonded with two polyurethane-based adhesives (flexible adhesive, stiff adhesive) onto a marine polyurethane top coat, is investigated. The investigated joint connections on the coatings exhibited a high mechanical stability even after accelerated ageing (salt spray exposure, cyclic temperature variations, high relative humidity). The aged joints retained up to 81% of their tensile strength and up to 92% of their lap-shear strength. The torsional rigidity of the adhesive joint exceeded the required clamping torque of the designed bolt. A cyclical lifetime of >9·10⁶ load cycles was estimated. Effects of cyclic ageing on the creep performance of the adhesive joint were found to be insignificant. Under tensile loads, the joints with stiff adhesive material exhibited a linear-elastic performance without the capability to deform prior to failure. The joints with the flexible adhesive material, in contrast, exhibited a behavior typically for ductile materials featuring a pronounced yield plateau prior to failure. Failure loads were higher, and displacement was notably lower, for the joints with stiff adhesive material. All joint connections met the requirements for a safety factor for the design for marine applications (11.6 for the flexible adhesive; 14.3 for the stiff adhesive). When the flexible adhesive is applied, the cohesive strength of the adhesive material is the limiting design factor. When the stiff adhesive is utilized, the load carrying capacity is higher, and the interface between priming coat and steel substrate is the limiting design area of the joints. The strength utilization of the adhesive materials depended on the particular structure of the entire joint configuration, particularly on the interface between steel substrate and the coating material. A number of assessment factors, namely stress limit factor, coating adhesion factor and safety factor, are introduced and discussed for tensile and shear loads.     

船舶轻量化T型连接结构设计及强度试验

文章从船舶轻量化的角度出发,提出了一种由复合材料夹芯板和增强泡沫胶接而成的新型T型连接结构,解决了船舶复合材料上层建筑内部壁板之间的连接问题。基于复合材料结构的设计原理和力学特性,设计了T型连接结构的拉伸试验和压缩试验,研究其在不同载况下的极限承载和损伤模式,证明T型连接损伤模式复杂,抗拉能力弱,尤其面板与腹板连接区的胶层是承载薄弱环节;依据试验结果验证数值计算方法,并规划3条技术路径以研究T型连接的抗拉特性,应用数值方法提取对应技术路径的应力和位移特征量,分析T型连接面板与腹板连接区的胶层几何参数对抗拉强度和重量的响应规律,获得连接区胶层几何夹角的建议取值为45°~60°,为复合材料船舶轻量化胶接结构的优化设计和实际应用提供了有益参考。     

Mechanical behaviour of vinylester adhesive joints used in laminated material for steel structures

One of the most important applications of adhesives in shipbuilding is the manufacturing of structural laminated materials. The application of these types of hybrid materials in a marine environment for extended periods of time and under adverse environmental conditions results in the accelerated degradation of the adhesive. Therefore, a specific experimental procedure is required to ensure the adequate performance of this adhesive bonded joint during its service life. In this study, an experimental method to analyse a vinylester adhesive in steel–adhesive–steel test specimens was applied (“mixed cantilever beam” specimens were used and mixed mode tests were carried out to obtain the fracture envelope). It was concluded that the energy release rate increased with the stress mode under dry conditions. In addition, the cohesive laws of vinylester showed that both the tangential stress and the strain are higher than the normal stress and strain. Finally, it was observed that adding distilled water to the adhesive joint for short periods of time improved its fracture strength.     

新的皮带机纠偏技术研究与应用

从受力平衡的角度,分析皮带机跑偏的各种因素及常用纠偏方法的不足,研制了一种带传感装置的新 型自动纠偏装置。它能同时自动调整胶带3个方面的受力,使跑偏的胶带迅速回位,实际应用取得了很好的效果。     

纳米碳酸钙表面接枝改性对环氧胶粘剂性能的影响

纳米碳酸钙在胶粘剂中的聚集团聚会影响其在胶粘剂中得到广泛的应用,因此,采用改性剂改性纳米碳酸钙成了控制其团聚的有效措施．采用傅立叶红外光谱（RTIR）、热重（TG—DTA）、扫描电镜（SEM）、剪切强度等测试方法研究了DL-α-丙氨酸改性纳米碳酸钙的改性机理,并将其做为填料加入到树脂中,研究其对环氧胶粘剂粘结性能的影响．结果表明：DL-α-丙氨酸以化学键合的方式吸附在纳米碳酸钙的表面,改性纳米碳酸钙在环氧胶粘剂中分散性良好,其填充的环氧胶粘剂,使剪切强度提高了2MPa．由此得出：改性纳米碳酸钙作为环氧胶粘剂的填料,可以有效地提高胶粘剂的粘结性能．