Ag-Cu-Ti急冷钎料钎焊Si3N4陶瓷接头界面结构及性能

采用（Ag72Cu28）％Ti4急冷钎料钎焊Si3N4陶瓷,研究联接温度、时间和压力等工艺参数对Si3N4陶瓷的接头界面结构以及强度的影响,并与同成分的常规钎料进行对比．研究结果表明：钎焊温度、保温时间和钎焊时施加的压力对钎焊接头强度均有影响,主要通过影响反应层结构和厚度来体现;Si3N4／（Ag72Cu28）96Ti4界面微观结构为Si3N4／TiN／Ti—Si化合物／Ag-Cu共晶;在相同的试验条件下,采用（Ag72Cu28）96Ti4急冷钎料钎焊的接头强度比常规钎料钎焊的接头强度提高37％．     

金塘大桥箱梁湿接头裂缝的原因分析与防治措施

本文阐述了金塘大桥非通航孔桥箱梁湿接头裂缝产生的情况,并结合现场施工的实际分析了裂缝产生的可能原因,同时为避免后期施工的湿接头产生裂缝提出了防裂措施。     

5900DWT沥青船开发和设计

5900DWT沥青船是一种全新的船型,设计过程中需要考虑高温、热传导损失、弹性联接等高温船的特点。该船型采用独立液货舱的特殊结构形式,并进行了有限元非线性校核,满足大部分油船的布置,其中管系布置较常规船型更为复杂。     

中部地区水泥路面切割缝的伸缩量测定及填缝材料的选择

阐述了填缝材料的选用原则和性能要求,对我国中部地区水泥路面的几个路段的切割缝的伸缩缝进行了实地测量,并考察了填缝材料的使用情况,发现气候差异、材料性能及是否及时对切割缝进行处理等是导致水泥混凝土路面产生各种病害的原因,提出填缝材料必须具有良好的粘结性、优良的耐候性和一定的弹性恢复能力和抗嵌入能力。     

钢桁架拱梁组合体系桥梁的总体设计研究

结合现有钢桁架拱梁组合体系桥梁资料,对其总体设计中的拱肋桁架布置形式、拱轴线的选取、矢跨比、拱顶和拱脚高度的选择、杆件截面形式、桁架节点的构造等方面进行了研究和比对。     

影响填挖方结合段的质量因素及防治措施

结合工程实际．分析了路基填挖方结合段常见病害及成因．并提出了工程防治措施。     

毛勒伸缩缝工作原理及安装工艺

毛勒伸缩缝是一种钢橡胶组合型桥梁伸缩缝,具有安全传递荷载、密封防水性良好、伸缩自如、施工安装简便等特点．是目前国际上先进的桥梁伸缩装置。介绍了毛勒伸缩缝的结构和工作原理．并结合河龙线、保衡线等路线的建设经验。介绍了毛勒伸缩缝的设计与施工工艺。     

软体排浅滩陡坡对铺施工工艺

在长江南京以下12. 5 m深水航道建设工程一期工程通州沙Ⅱ标段实施中,存在有大范围高滩排和深水排过渡段的软体排铺设。针对如何实现浅滩陡坡软体排一次性铺设的问题,进行船舶选型和施工方法的研究和论述,采用浅滩陡坡对铺施工工艺,实现了高滩排和深水排过渡段的一次性铺设,避免了软体排分幅搭接可能导致的质量问题,能够有效地保证施工质量,为类似工程提供参考和借鉴。     

Three Dimensional Numerical Simulation Study on the Tensile Test of the Embedded Components in Segment Joints of Deep Buried Storage and Drainage Shield Tunnels北大核心CSCD

The numerical simulation was carried out based on tensile test of the embedded components in segment joints of the deep buried storage and drainage shield-driven tunnel in Shanghai in order to study the numerical approach for mechanical analysis of segment joints of the tunnel. Using the concrete damage plasticity model and nonlinear springs, the 3D refined numerical model was established, in which the embedded components with complex geometries and the bond-slip behaviors between the concrete and bars were taken into consideration. Three kinds of embedded component models with different degrees of refinement were established and simply loaded. By comparing the calculation results and considering the spent time and the accuracy of calculation, the simplified form of the embedded components used in the overall model was determined. Nonlinear springs between anchor bars and concrete were set in the model in order to simulate the bond-slip behavior between them. In addition, two contrast models were also established using binding constraint and face-face contact constraint between concrete and anchor bars respectively. The three types of models were loaded in accordance with the test conditions. Comparing the results of the numerical calculation with the test results, it is shown that the "nonlinear spring model", which takes the bond-slip behavior into consideration, is more consistent with the test results than the "face to face contact model" and "binding model". And the model also reflects the failure mode very well. It indicates that the three dimensional refined modeling method used in this paper is applicable for similar tensile tests. © 2018, Editorial Office of "Modern Tunnelling Technology". All right reserved.     

薄板焊接变形高精度预测方法的研究

采用固有应变方法预测焊接变形时,传统方法是把纵向收缩、横向收缩和角变形这三成分作为接头的固有变形来估算焊接变形。但是,由于薄板的刚度低,在纵向方向上的弯曲变形也较明显,采用传统方法会影响薄板焊接变形的预测精度。为提高精度,文章对传统的方法进行了改进,开发了包括考虑纵向弯曲在内的四成分固有变形数值计算方法来预测薄板焊接变形。数值模拟结果表明:运用该方法预测薄板的焊接变形时,比传统的方法有更高的精度,而且预测结果与热弹塑性有限元的模拟结果十分吻合。