节点文献
金属涂层结合性能的复合弹丸撞击方法研究
【作者】 张强；
【导师】 吴志林；
【作者基本信息】 南京理工大学 ， 机械工程， 2012， 硕士
【摘要】 采用新型复合弹丸撞击法,对金属涂层界面间的结合强度进行了理论分析与试验研究。采用应力波理论,建立了一维应力波模型,对复合弹丸撞击过程中应力波传播过程与规律进行分析；接着,建立复合弹丸撞击金属涂层钢板的试验系统,以弹道枪作为发射装置,采用覆有金属薄膜的弹丸撞击涂层试件,发现了试件上涂层剥落现象,验证了弹丸撞击法的可行性；基于此,采用非线性有限元程序ANSYS/LS-DYNA对复合弹丸撞击涂层钢板的过程进行了数值仿真,获得了基体厚度、弹头薄膜与钢板涂层厚度的比值、弹丸撞击的速度等参数变化时,基体及界面涂层侧法向的应力分布情况,分析了镍涂层与陶瓷涂层对结合性能的影响,并分析了应用壳单元与实体单元在本模型中仿真薄膜与涂层时,得到不同单元对仿真结果精度的影响；结合之前的应力波理论解,将有限元仿真结果与之对比,进行理论上的相互验证；最后提出了应力测量的测试系统,介绍了测试原理,分析了以PVDF压电传感器的不同测量模式下的电路特点,并应用Multisim对测量电路进行仿真与分析。
【Abstract】 A new method of a composite bullet impact against the metal covered with a film is proposed to analyze and research the bonding strength between the metal and film. The work contains two aspects both in theory and experiment.A one-dimensional model is established by the theory of Stress-wave in order to find the rule of the process of composite projectile impacting. Secondly, establish an experimental system of this new method. A ballistic gun is used to launch bullet with a metallic coating to impact the specimen. The result is that the film is falling from the metal and it verifies the feasibility of this method. For this reason, the process of projectile impacting against the specimen is also simulated by using transient explicit finite element code ANSYS/LS-DYNA. Base qualitative analysis of the thickness, the ratio of film and the substrate and the velocity of bullet on the interface normal stress and substrate stress by means of numerical simulation. Analyze the performance of combination when the substrate is covered with different films, for example, the nickel or the ceramic film. Make a contrast and analyze shell elements and solid elements which used to simulate the coating and film in order to get the accurate result of numerical simulation. Theoretical arithmetic of stress wave and numerical simulation are combined to comprise and analyze. At last, put forward a stress test system, describe the test principle and analyze PVDF piezoelectric sensors to measure different characteristics of the circuit mode, and uses the software of Multisim to do circuit simulation and analysis.