Welding of medium-carbon structural steel

The optimum filler material was selected and the technological and mechanical properties and structure welded joints are investigated.     

单一节理岩体R—R破坏准则及参数确定

为评价岩体中节理对岩体强度特性的影响，分析了单一节理的分布性状，介绍了单一节理岩体破坏的Ｒａｏ－Ｒａｍａｍｕｒｔｈｙ准则及其参数试验确定方法，并应用于峨口铁矿采场边坡两种典型的单一节理岩体强度的研究。     

Laser probe measurements of quality evolution of solder joints during thermal cycling ageing tests

We present the results of a non-destructive measuring method allowing us to characterize the evolution of solder joints during thermal cycling ageing tests. The method uses a high resolution optical probe to detect selectively pure Joule and Peltier thermal responses of the solder joint subject to a given current pulse. The results show the Peltier and Joule responses to be good indicators for the evaluation of the age and the degradation of solder joints.     

空间异型节点极限承载力有限元分析

运用有限元分析软件 ANSYS,考虑材料非线性和几何非线性,对某工程一空间异型相贯节点进行了非线性分析,考察了该节点的应力分布、变形特征和塑性区扩展情况,得出了该节点的极限承载力,并将分析结果与足尺试验结果进行了比较,结果表明所建立的有限元模型较为准确地描述了节点的实际受力性能。最后对该节点的优化设计提出了一些有参考价值的建议。     

轻钢结构刚架支撑设计

简要介绍刚架支撑的设计原理,提出刚架支撑的设计方法及节点构造。根据《钢结构设计规范》(GB 50017-2003)选取合适的纵向水平位移容许值,并用一工程实例加以说明。     

混凝土雷达(超声法)检测混凝土结构施工缝

超声检测技术是混凝土非破损检测技术中的一个重要方面,在混凝土结构工程检测中应用极为广泛,特别是在检测混凝土内部缺陷与匀质性等方面非常有效。     

Special features of brazing VZhM4 and VZhM5 single crystal alloys

The processes of recrystallization of single crystal nickel creep-resisting alloys in brazing were investigated. The methods of preventing recrystallization of the single crystal alloys are described. The microstructure of the brazed joints in the VZhM4 and VZhM5 alloys is investigated. The effect of heat treatment on the microstructure of the brazed joints in the VZhM4 and VZhM5 alloys is described and the strength of the brazed joints determined.     

The effect of cataphoretic and powder coatings on the strength and failure modes of EN AW-5754 aluminium alloy adhesive joints

The aim of this study is to determine the effect of cataphoretic and powder coatings and also the method of application the primer on the adherends surface on the strength and failure modes of EN AW-5754 aluminium alloy adhesive joints. The study is performed on lap joints made of EN AW-5754 aluminium alloy, subjected to three different types of surface treatment; namely a) polyurethane cataphoretic coating, b) powder coating based on black mat RAL 9005 UL polyester resin and c) no coating. The tested adhesive joints were made using a one-component polyurethane adhesive Terostat 8596, which was dedicated for automotive and cured under a constant load of 0.018 MPa at 20 ± 2 °C. In addition, this study investigates the effect of the application of Terostat 8519P adhesion promoter which is a liquid polyurethane-based primer containing solvents and which is corresponding to Terostat 8596 polyurethane adhesive. Terostat 8519P adhesion promoter was applied in two different ways: a) to one substrate and b) to both substrates. The produced adhesive joints were subjected to strength tests using the Zwick/Roell Z150 testing machine. The examination of fracture in the tested adhesive joints was performed in accordance with the EN ISO 10365 standard. The shear strength results have demonstrated that both the method of application of the adhesion promoter (Terostat 8519 P) and the presence of cataphoretic coating had an influence on adhesive joints strength. The use of the adhesion promoter significantly affects the strength of both uncoated EN AW-5754 aluminium alloy adhesive joints and the adhesive joints subjected to powder coating. The use of the adhesion promoter has a less significant effect on the cataphoretic-coated samples.     

Solid state reactions between SiC and Ir

Reactivity between SiC and Ir as a function of SiC-crystallinity was investigated by diffusion bonding technique under a vacuum and over the temperature range of 1200–1450 °C. As reaction products, various Ir-silicides and free unreacted-C were detected. Reactivity is strongly affected by the temperature and SiC-crystallinity involving a series of interactions, from “no reaction” to “massive exothermic reactions”. In particular, interfacial phenomena are more pronounced by the presence of defects and grain boundaries.Solid state reactions result in formation of fine C-precipitates rearranged in a quasi-periodic microstructure. On the contrary, clustering of highly ordered C-precipitates (C-graphitized) occurs after “massive reactions” take place.A relationship between the degree of graphitization (from 1 to multi-layers of graphene), temperature and SiC crystallinity was found by Raman spectroscopy. 2D-layering phenomenon is enhanced in polycrystalline SiC at high temperature.