Mechanical behavior of metal-composite joints under impact rates of loading
Mechanical behavior of metal-composite joints under impact rates of loading
复制标题
DOI：
--
复制
发表时间：
2014
期刊：
影响因子：
--
通讯作者：
D. S. González
中科院分区：
文献类型：
--
作者：
D. S. González
金属-复合材料接头在冲击载荷下的力学行为。Gonzalez金属复合材料结构有着广泛的应用，尤其是在汽车、船舶和航空航天领域。材料成分之间的连接机制可以说是任何结构中最关键的组成部分。虽然在静态和循环荷载条件下的结构节点的力学行为已被彻底研究，很少有研究已经在加载的冲击率。由于实际上每个结构都受到时间相关的刺激，因此了解结构节点在动力状态下的行为是至关重要的。在这项研究中，开发了分离式霍普金森压杆（SHPB）来在铝/S2玻璃单搭接头上诱导轴向拉应力脉冲。研究了不同边缘距离（e）与螺栓直径（d）比（单搭接接头中的一个关键参数）下螺栓连接、胶接和混合（螺栓连接/胶接）接头的连接方法对强度和失效模式的影响。结果表明，接头强度随e/d的增加而增加，并且在e/d 3和4之间，失效模式从灾难性失效转变为渐进性轴承损坏。研究结果还表明，混合接头具有较低的E/D比表现出相当的强度螺栓连接在较高的E/D比。在铝/E-玻璃和先进高强度钢（AHSS）/S2-玻璃单搭接螺栓和混合接头中，还考虑了替代材料组合和表面处理对接头性能的影响。此外，在80°C下研究了单搭接接头在高温下的机械行为。在所研究的e/d比范围内，螺栓和混合接头的接头强度均降低了20-30%。建立了单搭接结构节点的设计准则，考虑了e/d比、连接方法、材料成分、表面处理和环境影响。
MECHANICAL BEHAVIOR OF METAL-COMPOSITE JOINTS UNDER IMPACT RATES OF LOADING By David S. Gonzalez Metal-Composite structures have a wide array of applications, most notably in the automotive, marine, and aerospace disciplines. The joining mechanism between the material constituents is arguably the most critical component of any structure. While the mechanical behavior of structural joints under static and cyclic loading conditions has been thoroughly investigated, very little research has been performed at impact rates of loading. Since virtually every structure is subjected to time-dependent stimuli, it is essential to understand the behavior of structural joints in the dynamic regime. In this study, a Split Hopkinson Pressure Bar (SHPB) was developed to induce an axial tensile stress pulse on Aluminum/S2-glass single-lap joints. The effect of joining method on strength and failure mode was investigated for bolted, bonded, and hybrid (bolted/bonded) joints at varying edge distance (e) to bolt diameter (d) ratios, a critical parameter in single-lap joints. It was demonstrated that joint strength increases with e/d and that failure mode transitions from catastrophic failure to progressive bearing damage between e/d 3 and 4. The findings also suggest that hybrid joints with lower e/d ratios exhibit comparable strength to bolted joints at higher e/d ratios. Effects of alternative material combinations and surface preparation on joint performance were also considered in Aluminum/E-glass and Advanced High Strength Steel (AHSS)/S2-glass single-lap bolted and hybrid joints. Additionally, the mechanical behavior of single-lap joints at elevated temperatures was investigated at 80°C. Both bolted and hybrid joints over the investigated range of e/d ratios exhibited a 20-30% decrease in joint strength. Design guidelines were established for single-lap structural joints with consideration for e/d ratio, joining method, material constituents, surface preparation, and environmental effects.