异质板材嵌入式冷压变形连接成形规律研究

发布时间：2018-02-27 14:00

本文关键词： 异质板材嵌入式冷压变形连接连接强度连接质量　出处：《哈尔滨理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着社会的不断进步与发展，环保等问题受到的关注与日俱增。在追求节能减排等实效的驱动下，大量的新型材料或结构被航空航天、汽车制造等领域广泛采用。异质材料连接作为实现轻量化的主要途径之一逐渐成为研究者们共同关注的焦点，与激光焊、搅拌摩擦焊等方法相比，螺纹连接、铆接和冲压连接等机械连接方法在解决异质板材连接过程中存在的板厚差异大、层数多等瓶颈问题中更具优势。为了进一步提高异质板材连接的法向承载能力及可靠性，本文提出了嵌入式板材冷压变形连接法即对连接部位整体加载作用后，一侧板材受压变形后嵌入到对侧板材的预制孔中形成互锁连接结构。并设计了搭接-嵌入式、交互-嵌入式和插孔-嵌入式等三种不同的接头结构方案，以工业纯铝1100与304不锈钢板为例，利用万能材料试验机进行连接实验及连接强度测试。本文首先确定了异质板材冷压变形连接过程可分为三个主要阶段：调整阶段、压合阶段和嵌入阶段，结合各阶段的变形连接特征揭示了其主导的因素并加以深入阐述；然后研究了加载压力、预制孔型和冲头压下量等对异质板材冷压变形连接过程及连接质量等方面的影响。其中，，利用有限元模拟分析了不同方案连接过程中的两板材接头部位的塑性变形特征、金属流动行为和嵌入充填行为等规律；又借助工艺实验研究了板材连接部位的宏观形貌、宽度及厚度变化并进行了工艺优化，结合具体工艺条件分析确定失效形式及内因机理。上述研究结果表明，不同方案连接过程中铝板在加载压力作用下均有向不锈钢板预制孔内产生充填流动并嵌入其中的趋势。同时，连接部位的厚度均为从对称面处向两侧依次递减且与加载压力呈反比关系变化。经三种冷压变形连接方案连接强度的对比可得知，插孔-嵌入式方案明显高于其它两种方案。
[Abstract]:With the continuous progress and development of the society, environmental protection issues are getting more and more attention. Driven by the pursuit of energy saving and emission reduction, a large number of new materials or structures have been aerospace, Heterogeneity material connection as one of the main ways to achieve lightweight has gradually become the focus of attention of researchers. Compared with laser welding, friction stir welding and other methods, thread connection, The mechanical connection methods such as riveting and punching are more advantageous in solving the bottleneck problems such as large difference in thickness and number of layers in the process of heterogeneous plate joining. In order to further improve the normal bearing capacity and reliability of the heterogeneity plate connection, this paper proposes an embedded plate cold-pressing deformation connection method, that is, after the integral loading of the connection site, After compression deformation, one side plate is embedded into the prefabricated hole of the opposite side plate to form interlocking connection structure. Three different joint structure schemes are designed: lap-embedded, interactive-embedded and Jack-embedded. Taking the industrial pure aluminum 1100 and 304 stainless steel plate as an example, the connection experiment and the joint strength test were carried out by using universal material testing machine. In this paper, we first determine that the process of cold-pressing deformation of heterogeneous plates can be divided into three main stages: the adjustment stage, the compression stage and the embedded stage. Combined with the deformation and connection characteristics of each stage, the dominant factors are revealed and explained deeply. Then, the effects of loading pressure, preform pass and punch reduction on the connection process and connection quality of heterostructure sheet are studied. The plastic deformation characteristics, metal flow behavior and embedded filling behavior of the joint of two plates are analyzed by finite element simulation, and the macroscopic morphology of the joint is studied by means of technological experiments. The width and thickness of the process were optimized, and the failure form and internal mechanism were determined by analyzing the specific process conditions. The results show that under the loading pressure, the aluminum plate has the tendency of filling flow and embedding in the prefabricated hole of stainless steel plate during the connection process of different schemes. The thickness of the connection site decreases from the symmetrical plane to the two sides in turn and is inversely proportional to the loading pressure. Through the comparison of the connection strength of the three cold compression deformation connection schemes, it can be seen that the Jack embedded scheme is obviously higher than the other two schemes.
【学位授予单位】：哈尔滨理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG457.19

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