摘要：The lightweight and high efficiency of natural structures are the inexhaustible sources for engineering improvements. The goal of the study is to find innovative solutions for mechanical lightweight design through the application of structural bionic approaches. Giant waterlily leaf ribs and cactus stem are investigated for their optimal framework and superior performance. Their structural characteristics are extracted and used in the bio-inspired design of Lin MC6000 gantry machining center crossbeam. By mimicking analogous network structure, the bionic model is established, which has better load-carrying capacity than conventional distribution. Finite Element Method （FEM） is used for numerical simulation. Results show better specific stiffness of the bionic model, which is increased by 17.36%. Finally the scaled models are fabricated by precision casting for static and dynamic tests. The physical experiments are compared to numerical simulation. The results show that the maximum static deformation of the bionic model is reduced by about 16.22%, with 3.31% weight reduction. In addition, the first four natural frequencies are improved obviously. The structural bionic design is a valuable reference for updating conventional mechanical structures with better performance and less material consumption.

摘要：低散射金属支架是隐身武器研制过程中的重要装备,主要用于电磁散射测量中的目标支撑。在紧缩场中对待测目标进行RCS测量时,目标定位结构形式及支架整体刚度性能非常重要。本文对橄榄形截面金属支架结构特点进行了分析,并计算了空间转轴位置参数。在200 kg载荷下进行力学分析,借助ADAMS对运动特性进行了仿真分析,得到了运动关系曲线,为此类金属支架原动装置的设计制造提供有效的参考依据。

摘要：High-speed machine tool working table restrains the machining accuracy and machining efficiency,so lightweight design of the table is an important *** nature,leaf has developed a plate structure that maximizes the surface-to-volume *** can be seen as a plate structure stiffened by *** with a high-speed machine tool working table,leaf veins play a role of supporting part which is similar to that of stiffening ribs,and they can provide some new design ideas for lightweight design of the *** this paper,distribution rules of leaf veins were investigated,and a structural bionic design for the table was achieved based on regulation of leaf ***,statistical analysis on geometric structure of leaf veins was carried out,and four distribution rules were ***,relevant mechanical models were developed and analyzed in finite element *** on the results from mechanical analysis on those relevant models,the four distribution rules were translated into the design rules and a structural bionic design for the working table was *** simulation and experimental verifications were carried out,and results showed that the average displacement of the working table was reduced by about 33.9%.

摘要：A concept of Specific Structure Efficiency (SSE) was proposed that can be used in the lightweight effect evaluation *** main procedures of bionic structure design were introduced *** parameter relationship betweenhollow stem of plant and the minimum weight was deduced in *** order to improve SSE of pylons, the structural characteristicsof hollow stem were investigated and *** pylon was designed based on analogous biological *** finite element method based simulation, the displacements and stresses in the bionic pylon were comparedwith those of the conventional *** show that the SSE of bionic pylon is improved ***, dynamic andelectromagnetism tests were carried out on conventional and bionic *** weight, stress, displacement and Radar CrossSection (RCS) of both pylons were *** results illustrate that the SSE of bionic pylon is markedly improvedthat specific strength efficiency and specific stiffness efficiency of bionic pylon are increased by 52.9% and 43.6% *** RCS of bionic pylon is reduced significantly.

摘要：小型翼结构设计主要是确定翼梁、翼肋的形式、分布和尺寸,以满足机翼结构强度、刚度要求。生物骨架以其结构、材料的合理分布和组合满足生物体的多种功能需求,为飞行器结构仿生设计提供了不竭灵感。叶脉形状为椭圆形空心管,并且尺寸沿轴线逐渐减小,最主要结构特征是倾斜、交错、分叉,以适应不同部位应力分布特点。在分析小型翼结构设计特点的基础上,借鉴叶脉结构特征,利用相似原理,设计仿生型机翼结构。有限元分析表明,仿生机翼比原型机翼具有更高的结构效能。采用选择性激光烧结(Selectivelasersintering,SLS)技术制作原型与仿生型机翼样件,并对其进行静力弯曲试验,与原型机翼相比,仿生型机翼质量、变形、应力都相应减少,证实了小型翼结构仿生设计的有效性和有限元分析的可靠性。

摘要：针对薄壁件的轻量化设计要求,在对王莲叶脉分枝结构形态和构型规律分析基础上,以飞机盖板原型为对象,应用结构仿生设计方法,对盖板内部的筋板分布形式进行结构仿生设计,利用ANSYS APDL参数化设计语言建立仿生型结构的参数化模型并进行筋板结构参数优化.有限元分析结果表明,相对于原型盖板,结构参数优化后的仿生型盖板质量减小,比强度结构效能有较大提高,静力学性能明显改善.

摘要：通过溪洛渡水电站与三峡水库之间 ,40 0余km河道冲淤变形的多种途径研究 ,认识到坝下游宽级配卵石河床清水冲刷的冲刷量是有限的。悬移质基本不与床沙交换 ,上游水库淤积多少悬移质泥沙量 ,下游水库入库输沙量就几乎减少同样多的量 ;在上游水库推移质未出库前 ,下游水库入库推移质输沙量随时间增长呈递减。两库之间的河床变形不明显 ,河槽冲刷深度、水位下降幅度很有限 ,对环境影响不大。在不影响溪洛渡水电站的功能和效益的条件下 ,溪洛渡水库泥沙淤积后 ,对三峡水库的减沙效益是显著的。与三峡单库运行相比 ,不但减少了三峡水库淤积量 ,增加了调节库容 ,防洪库容 ,还降低了水库尾部洪水位 ,减小水库淹没损失 ,改善了通航条件。随着三峡上游若干大型水库不断修建 ,上游诸水库与三峡水库进行联合调水调沙 ,三峡泥沙问题将能延缓到大坝设计基准期以后出现。其前提是主要产沙区河流上拦沙能力很强的水库要尽早修建 ,其中最重要的就是金沙江上的白鹤滩水电站 ,必须加快设计 ,尽早建设。

摘要：利用结构仿生的方法对 Lin MC6000型咙门加工中心横梁的筋板结构进行了优化设计。通过对王莲叶脉构型规律的分析,提出了3种仿生构型并利用 Optistruct 软件进行了有限元仿真验证。结果表明,相对于传统的平行均布筋板,最优仿生型筋板的结构比刚度提高了17.36%,前4阶固有频率平均提高7.39%,体现了材料的优化分布和最大结构效能,并总结出横梁内部筋板设计的仿生学规律。这为突破机床构件的传统设计思路、实现结构轻量化提供了一种新方法。

摘要：分析了并联机构的姿态空间,指出了影响姿态空间的因素为物理约束和奇异约束2类,并且分别从这2个方面给出了扩大姿态空间相应的解决方案.以3PRS(PrismaticRevolve Spherical)并联机构为例,提出了采用新的铰链形式和增加冗余UPS(Universal Prismat-ic Spherical)支链来增大姿态空间的方法,详细描述了动平台能够实现在各个方向90°偏转的机构设计过程,并基于遗传算法以机构整个姿态空间中的灵活度为目标对机构进行了优化.优化的结果通过仿真证实了可靠性,这对于进一步扩大并联机构的应用范围提供参考.

摘要：由于机动性和能耗的要求,飞机设计过程当中轻量化设计是十分重要的。经过亿万年的进化,在承受自身重量及生长环境的载荷过程中,生物体获得了适应环境的最优结构。通过分析蜻蜓膜翅和飞机机身加强框的结构相似性,提取决定蜻蜓膜翅结构优良力学性能的结构特征,将其应用到飞机机身加强框的设计当中,并用有限元工具验证了结构的优化效果。在同样的承载条件下,仿生型结构的比刚度比原型结构提高了2%-6%,比强度提高了1%-8%。同时,仿生型结构的最大应力减小,而最小应力明显增大,因此其应力分布更加均匀,从而体现了仿生结构件材料的优化分布和最大效能。