船用铝-钢爆炸复合过渡接头性能要求及分析

对铝-钢爆炸复合过渡接头的材质及规格、制造工艺、标准规范、性能要求、焊接要求等方面进行了介绍及分析,为过渡接头的检验、验收和标准的修订提供了一定的参考。     

国内船用铝-钢爆炸复合过渡接头应用现状及展望

铝-钢爆炸复合过渡接头在船体设计建造中的应用日趋广泛,以常用的铝-铝-钢、铝-钛-钢两种材料组合为主要对象,对爆炸复合技术进行扼要介绍,分析过渡接头的基本性能特点,论述我国铝-钢过渡接头的材料体系、标准体系和焊接工艺方面的研究进展,分析铝-钢爆炸复合过渡接头在应用中存在的典型问题,指出应进一步完善现有铝-钢爆炸复合过渡接头的性能验证、焊接工艺、腐蚀防护等方面的要求,确保材料应用的安全可靠。     

铝-不锈钢复合过渡接头性能试验研究

针对铝-不锈钢复合过渡接头使用要求,对不同材质组合及爆炸工艺的铝-不锈钢过渡接头的常温力学性能、焊接模拟力学性能、微观金相、气密性进行了试验分析,发现温度对接头的力学性能及气密性有一定影响,并确定漏气的主要部位为铝铝界面和铝钛界面,这为改善该接头的气密性提供了研究方向。     

爆炸复合的研究现状和发展趋势

综述了爆炸复合的科技问题，着重介绍了爆炸复合的冶金效应和连接界面。还介绍了爆炸复合的基本的物理原理、应用研究以及工业应用。最后指出了爆炸复合理论及爆炸复合技术发展的最新动向。     

复合材料单搭接头的剪切强度对比实验研究

在常温和湿热高温的环境下,分别进行了三种不同的成碰工艺(RTM、引入缝纫的RTM和胶接)制备的单搭接头的剪切强度实验,研究了成型工艺对单搭接头的剪切强度的影响,并根据实验现象分析了单搭接头的剪切破坏机理.实验结果表明:引入缝纫的RTM成型试样的剪切强度性能最高,而胶接成型试样的剪切强度最低;环境温度对RTM和引入缝纫RTM成型试样的剪切强度影响不大,而对胶接成型试样的剪切强度有较大影响.     

某型船用铝合金-纯铝-钢复合过渡接头界面开裂微观分析

某型船用铝合金-纯铝-钢复合过渡接头焊接后界面开裂,从开裂位置取样,对开裂位置和未开裂位置进行金相分析和扫描电镜分析,结果表明,界面连续的铁-铝金属间化合物层是过渡接头界面开裂的主要原因。     

高聚物夹层材料对层压减振复合钢板拉伸剪切强度的影响

研究了高聚物夹层材料对层压减振复合钢板的拉伸剪切强度的影响。结果指出，高聚物夹层材料较厚时，层压减振复合钢板的拉伸剪切变形规律与高聚物夹层材料的一致；高聚物夹层厚度较小时，复合钢板的拉伸剪切强度较高。与酚醛树脂氯丁橡胶相比，聚氨酯作夹层的层压减振复合钢板具有较高的拉伸剪切强度。     

用爆炸法消除CF钢焊接残余应力可行性研究

对38mm厚CF烟焊接接头进行爆炸消除残余应力可行性试验,为使用调质钢建造的大型焊接结构消除焊接残余应力提供可行的工程方法。CF钢焊后存在很高的拉伸残余应力,爆炸处理可有效地消除残余应力;经爆炸处理后,CF钢除硬度有一定的提高外,其余常规力学性能不变。     

铝-钢爆炸焊接过渡接头的制造和应用

介绍了铝 钢爆炸焊接的特点 ,铝 钢过渡接头的制造方法、性能 ,以及在现代铝电解行业中的应用。     

Investigation of explosive welding parameters and their effects on microhardness and shear strength

The aim of this study was to investigate the strength of explosive welded metals with the same chemical compositions. Different welding interfaces (straight, wavy and continuous solidified-melted) were used with changing explosive welding parameters [stand-off distance (s), explosive loading (R) and anvils]. Joined metals were investigated under heat-treated and untreated conditions. Results on the microstructure, microhardness, tensile shear strength and bending tests are reported. According to the experimental results, the effect of the anvil on the explosive welding process was only the joining or not-joining performance. It was shown that the bonding interface changed from a straight to a wavy structure when the explosive loading and stand-off distance were increased. For wavy interfaces, when the explosive loading was increased the wavy length and amplitude increased. Results of tensile shear and bending tests showed that heat-treated specimens have more strength than untreated samples. According to tensile shear test results, straight and wavy interfaces had similar strength. In addition, in bending tests of untreated specimens it was shown that the bending zone had some cracks.     

复杂环境下建(构)筑物控制爆破拆除的设计与应用

结合湖南岳阳某水泥厂厂房控制爆破拆除情况,通过爆破方案及参数的设计,介绍了炸高的选取,以及利用控制爆破多段延时起爆技术的利弊,经过科学的理论计算采取了有效的防护措施降低了爆破危害,并通过爆破测振仪TC-4850测振数据详细分析了爆破拆除过程中的振动情况,为以后相关类似实例提供了宝贵工程经验。     

Fatigue strength of self‐piercing riveted joints in lap‐shear specimens of aluminium and steel sheets

The self‐piercing riveting (SPR) process is gaining popularity because of its many advantages. This study investigated the fatigue strength of SPR joints in tensile‐shear specimens with dissimilar Al‐5052 and steel sheets. A structural analysis of the specimen was conducted. For this specimen, the upper steel sheet withstood applied load in a monotonic test and played a major role in the low‐cycle region. In the high‐cycle region, however, the harder surface of the upper steel sheet reduced the fatigue strength by enhancing fretting crack initiation on the opposite softer aluminium surface. Therefore, the fatigue endurance of the specimen was reduced. The fatigue endurance of a SPR joint with the combination of steel and aluminium sheets was found to be governed by the strength of the lower sheet, which is more vulnerable to the applied loading. Thus, it is desirable to use a stronger metal sheet as the lower sheet with regard to the fatigue performance. Scanning acoustic microscopy was effectively used to reveal and prove the formation and growth of subsurface cracks in SPR joints. The structural stress can predict the fatigue lifetimes of the SPR joint specimens within a factor of three.     

舰船静置爆炸气泡时总纵强度计算方法研究

新型“大气泡能”概念武器在水下爆炸能产生大气泡，对船体总纵强度造成很大影响，有可能使舰体发生纵向折断或倾覆。为研究这种作用，建立了舰船静置爆炸气泡时总纵弯曲强度的理论计算方法。采用静置爆炸气泡的假设，将气泡产生的浮力损失和压力差转化为等效载荷，计算气泡作用后船体的总纵弯矩和剪力并进行强度校核。以某舰艇为例进行计算，结果表明，爆炸气泡作用下船体的剪力和弯矩比静浮状态增大很多，船体发生纵向折断破坏的危险性也随之增大。     

塑料超声波焊接过程及质量研究 III焊接接头质量影响因素分析

从焊接工艺参数对焊件熔化状态及焊件熔化状态对接头质量的影响两个方面对塑料超声波焊接质量影响因素进行了研究 ,揭示了焊件熔化状态是影响接头质量的直接因素 .利用光学显微镜研究了接头的组织形貌 ,发现接头熔合区组织具有明显的取向 .对接头剪切和弯曲强度进行测试 ,发现接头力学性能具有各向异性 ,熔和区厚度和组织取向程度对接头有重要的影响 .     

Numerical analysis of welded joint treated by explosion shock waves

This paper focuses on the simulation of welding residual stresses and the action of explosion shock waves on welding residual stresses. Firstly, the distributions of welding temperature field and residual stress on a butt joint were numerically simulated with the sequentially coupled method. Secondly, the effect of explosion shock waves, produced by plastic strip-like explosive, on welding residual stress distribution was predicted with coupled Lagrange-ALE algorithm. It was implicated that explosion treatment could effectively reduce welding residual stresses. The simulation work lays a foundation for the further research on the rule of explosion treatment’s effect on welding residual stresses and the factors that may influence it.     

A simulation-based investigation of the staircase method for fatigue strength testing

A critical evaluation of the statistics of the fatigue strength distribution as determined by the staircase (or up-and-down) method is presented. The effects of test parameters (namely, step size and sample size) were analyzed using numerical simulation to determine the accuracy of fatigue strength standard deviation calculations using traditional staircase statistics, resulting in a quantification of standard deviation bias as a function of step size and sample size. A non-linear correction was formulated to mitigate this standard deviation bias inherent in small-sample tests. In addition, the simulation was used to investigate the effectiveness of a bootstrapping algorithm on standard deviation estimates. The bootstrapping algorithm was found to significantly reduce the potential of large standard deviation errors in small-sample tests. Together, the use of the non-linear correction factor and the bootstrapping algorithm may allow an improved method to estimate the statistics of a material’s fatigue strength distribution using a small-sample staircase test strategy.     

Interlaminar shear strength evaluation of curved composite samples

To assess the bonding quality between the different layers of composite rings fabricated by filament winding it is necessary to choose a useful shear test. A method for measuring the shear strength of thin curved samples is proposed herein. Stress distribution within the probe is calculated and evaluated by finite element method.     

Microstructure and shear strength of Mo-Cu/Cr18-Ni8 brazing joint in vacuum

High density Mo-Cu composite and Cr18-Ni8 stainless steel were brazed with Ag-Cu filler metal in vacuum of 10⁻⁵ Pa. The microstructure characteristics of Mo-Cu/Cr18-Ni8 brazed joint were investigated by field-emission scanning electron microscope (FESEM) with energy dispersive spectrometer (EDS) and shear strength was measured by shearing test. The results indicated that a Mo-Cu/Cr18-Ni8 joint with shear strength of 125 MPa was obtained at 940 °C for 20 min. There were Ag-Cu eutectic and Cu-rich phase without brittle intermetallic compounds formed in the joint. The shear fracture exhibited plastic feature with shear dimple and fracture located at the interface between braze seam and Cr18-Ni8 stainless steel.     

HJ混凝土界面处理剂剪切强度的试验研究

为了提高混凝土界面处理剂的剪切强度，得到良好的剪切力学性能，文章研究了不同聚合物种类、掺量和不同灰砂比对界面处理剂剪切强度的影响，并分析了各自的作用机理。试验结果表明：不同聚合物种类具有不同的最佳掺量，可使得界面处理剂的剪切强度达到最高。