Actuation-softening in kagome lattice structures
Actuation-softening in kagome lattice structures
复制标题
kagome 晶格结构中的驱动软化
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
S. Guest
中科院分区：
文献类型：
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作者：
A. Leung;S. Guest
二维 kagome 晶格已被证明是主动变形结构的有前途的基础，具有低致动阻力和高被动刚度。线性致动器取代了桁架的一些构件：致动器的激活导致全局宏观形状变化。结构的线性行为，特别是高被动刚度，很大程度上取决于穿过结构的直杆；但当杆被驱动时，这种直线度就会被破坏。当前的论文通过施加大的驱动来产生几何非线性来研究这种行为。 kagome点阵中引入一列执行器，这样对于每个执行器，正上方和下方的执行器也会被激活；然后测量系统的水平刚度。数值结果表明，当执行器延伸时，在“临界”驱动应变下被动刚度会突然下降。该临界致动应变取决于晶格条的粗细度以及致动器本身的刚度。对于具有收缩执行器的晶格，刚度下降是逐渐的，并且不太严重。
The two-dimensional kagome lattice has been shown to be a promising basis for active shape-changing structures, having both low actuation resistance and high passive stiffness. Linear actuators replace some members of the truss: activation of the actuators results in a global macroscopic shape change. The linear behaviour of the structure, and in particular the high passive stiffness, depends crucially on the straight bars running across the structure; but this straightness is destroyed when bars are actuated. The current paper investigates this behaviour by imposing large actuations to create geometrically non-linearity. A column of actuators is introduced into a kagome lattice, so that for every actuator, the actuator directly above and below is also activated; the horizontal stiffness of the system is then measured. Numerical results show that when the actuators are extended, there is a sudden drop in passive stiffness at a ‘critical’ actuation strain. This critical actuation strain depends on the stockiness of the bars of the lattice, and the stiffness of the actuator itself. For lattices with contracting actuators, the stiffness degradation is gradual, and less severe.