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关键词： Crushing  

摘要： Here, to explore the optimal hierarchical size ratio of hierarchical honeycomb materials and improve their energy absorption Performance, a hierarchical honeycomb material model was established based on classical honeycomb materials and using self-similar honeycombs to replace honeycomb walls. Deformation mode, crushing force and energy absorption characteristics of self-similar hierarchical honeycomb materials under different impact velocity conditions were studied using numerical Simulation method. Effects of changes of hierarchical size on in-plane dynamic crushing behavior of self-similar hierarchical honeycomb materials were discussed in detail. The study results showed that self-similar hierarchical honeycomb materials have superior mechanical properties and energy absorption capacity compared to honeycomb materials;crushing forces of self-similar hierarchical honeycomb materials exhibit a trend of firstly increasing and then decreasing with increase in hierarchical size ratio;H-18 self-similar hierarchical honeycomb material has the largest crushing force, and under low-speed impact conditions, the average crushing force of H-18 self-similar hierarchical honeycomb material is 600% higher than that of H-0 honeycomb material;In addition, if hierarchical size ratio varies, abilities of self-similar hierarchical honeycomb materials to adapt to impact velocity changing also vary, and the optimal hierarchical size is proposed to provide a theoretical basis for systematic studying and application of hierarchical honeycomb materials. © 2025 Chinese Vibration Engineering Society. All rights reserved.

关键词： 甘草   凯纹透翅蛾   幼虫   Iwao回归分析法   Taylor幂法则   空间分布型   抽样技术  

摘要： 为了明确凯纹透翅蛾幼虫在甘草根部的为害及其空间分布型和理论抽样技术，为科学开展该害虫的虫口调查和防治工作提供技术支撑，试验采用6种聚集度指数（C、Ca、I、m*、m*/m、k）、Iwao回归分析法和Taylor幂法则分析研究了甘草根部凯纹透翅蛾幼虫的空间分布型，应用Iwao理论抽样和序贯抽样技术，计算了Blackith聚集平均值λ，分析了凯纹透翅蛾幼虫种群聚集的原因，建立甘草根部凯纹透翅蛾幼虫田间调查的理论取样数量和序贯抽样模型。结果表明，凯纹透翅蛾幼虫对不同年生甘草的危害率为4.83%～43.00%，平均虫口密度为0.02～1.75头/株。凯纹透翅蛾幼虫在甘草田间的空间分布模式总体上呈聚集分布，分布的基本成分为个体群，且个体间相互吸引，受种群密度的影响较大，随着种群密度的上升，其聚集的程度也逐渐增强，聚集原因是由环境条件和其固有特性共同作用的结果。进一步分析提出了不同种群密度下凯纹透翅蛾幼虫的理论抽样模型和基于防治指标的序贯抽样技术。

关键词： Antenna phased arrays  

摘要： Large antennas have important application backgrounds in aerospace engineering fields of earth observation and space-based early warning. However, due to their large size, high flexibility and low damping, they are prone to generate significant nonlinear vibration during in-orbit operation. Here, nonlinear dynamic behavior and active vibration control of large spatial planar phased array antennas were studied. Firstly, the nonlinear finite element method was used to solve geometric nonlinear dynamic problem of antenna structure. Secondly, a cable actuator was used to control vibration of antenna structure, and a design method for the control law considering the unidirectionality and saturation of cable control force was proposed. Finally, the theoretical study results were verified with numerical simulation. The simulation results showed that the proposed control strategy can effectively suppress vibration of the studied antenna structure. © 2025 Chinese Vibration Engineering Society. All rights reserved.