高g值冲击下泡沫铝填充变截面壳缓冲吸能特性研究

发布时间：2018-03-25 15:13

本文选题：侵彻　切入点：变截面壳　出处：《中北大学》2017年硕士论文

【摘要】：在弹体侵彻硬目标过程中,弹载测控电路承受高g值加速度冲击作用。为了对测控电路进行更好的缓冲保护,本文提出了阶梯形变截面金属壳的几何构型。在不同半正弦高g值加速度载荷下,设计了多组不同厚度的变截面壳及等效厚度的圆柱壳作为缓冲元件,对记录电路进行单次或者多次缓冲保护,从屈曲模态、比吸能、加速度缓冲效果等方面进行缓冲吸能特性评估。并通过落锤试验对结构的缓冲特性进行验证。此外,泡沫铝填充壳结合了壳结构载荷波动小和泡沫铝具有变形能力大、密度小等优点,因此,以冲击过程中泡沫铝填充变截面壳吸收能量最大化及测控电路承受加速度幅值最小化为目标约束函数,壳厚度及泡沫铝密度为优化参数,基于多项式响应面模型和目标规划法对泡沫铝填充变截面壳的缓冲吸能特性进行了多目标优化。最后以变截面壳和优化的泡沫铝填充壳结构作为缓冲元件在弹体侵彻多层钢板情况下对记录电路进行缓冲保护。结果表明:(1)变截面壳的屈曲模态为从厚度较小一端依次屈曲变形的轴对称叠缩模式,这样更好地降低了加速度初始幅值,又能避免后阶段被压实而导致的加速度幅值大幅度增大的情况,且吸能效果相对是最理想的,因此,变截面壳对于弹体侵彻多层靶时对电路的缓冲保护具有重要研究意义。(2)多目标优化综合考虑了评价结构抗冲击性能的多个重要指标,在一定载荷作用下对于选取更优的缓冲结构具有重要指导意义。
[Abstract]:In the process of projectile penetration into hard target, the projectile measurement and control circuit is subjected to high g acceleration shock. In order to better buffer the measurement and control circuit, In this paper, the geometric configuration of stepped metal shell with variable cross section is presented. Under different acceleration loads with high g value of half sinusoidal value, several groups of variable section shells with different thickness and cylindrical shells with equivalent thickness are designed as buffer elements. The single or multiple buffering protection of the recording circuit is carried out, and the buffered energy absorption characteristics of the structure are evaluated from the aspects of buckling mode, specific energy absorption and acceleration buffering effect, and the buffer characteristics of the structure are verified by the drop weight test. The aluminum foam filled shell combines the advantages of small load fluctuation of shell structure and large deformation ability and low density of aluminum foam. The objective constraint function is to maximize the absorption energy of aluminum foam filled shell with variable cross section and minimize the acceleration amplitude of measurement and control circuit. The thickness of shell and the density of aluminum foam are optimized parameters. Based on polynomial response surface model and objective programming method, the energy absorption characteristics of aluminum foam filled with variable cross section shell are optimized by multi-objective method. Finally, the variable section shell and the optimized aluminum foam filled shell structure are used as buffer elements in projectile body. The results show that the buckling mode of the variable section shell is an axisymmetric stacking mode of buckling and deformation from one end to the other. In this way, the initial amplitude of acceleration can be reduced better, and the acceleration amplitude caused by compaction in later stage can be avoided, and the energy absorption effect is relatively ideal. The variable cross section shell is of great significance for the buffer protection of the circuit when the projectile penetrates the multilayer target.) the multi-objective optimization considers several important indexes to evaluate the impact resistance of the structure. It is important to select a better buffer structure under a certain load.
【学位授予单位】：中北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TJ410;TB383.4

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