Characterization of micro-scale creep deformation of an electro-active paper actuator
Characterization of micro-scale creep deformation of an electro-active paper actuator
复制标题
电活性纸致动器微尺度蠕变变形的表征
DOI：
10.1088/0964-1726/18/9/095008
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发表时间：
2009
影响因子：
4.1
通讯作者：
Chulho Yang
中科院分区：
文献类型：
--
作者：
Sang;Joo;Kwang;Jaehwan Kim;H. Kim;Chulho Yang
通过采用逐步自重加载来研究电活性纸（EAPap）致动器的蠕变变形过程。为了了解 EAPap 薄膜的变形机制，包括形态和结构变化，对玻璃纸 EAPap 施加了低于屈服强度的各种载荷条件。从结构观察来看，在低于屈服强度10%的外加载荷下检测到了微韧窝和微裂纹，而在更高的载荷条件下则没有发现它们。据推测，在低负载条件下，只有非晶区域中的短且随机的纤维可以响应所施加的应力，而不是结晶区域中的纤维。结果，局部点处的变形能量积累并在表面产生了微缺陷。同时，当蠕变载荷增加到高水平时，结晶区中的纤维可以承受大部分载荷。纤维中的分子链可以在高负载下旋转和伸长。仅在高负载水平下才观察到拉长的纤维。根据作为所施加载荷的函数的结构变化，通过广角 X 射线测量仅在高载荷条件下观察到晶体取向的峰移。这可以证实蠕变变形可能引起 EAPap 的结构变化。
The creep deformation process of an electro-active paper (EAPap) actuator was investigated by adapting stepwise dead-weight loading. To understand the deformation mechanism of the EAPap film, including morphological and structural changes, various loading conditions below yield strength were applied to cellophane EAPap. From the structural observation, micro-dimples and micro-cracks were detected at applied load lower than 10% of yield strength, while they were not found in higher load conditions. It is hypothesized that only short and random fibers in the amorphous region may respond to the applied stress at the low loading condition, not the fibers in the crystalline area. As a result, deformation energy at the localized spot accumulated and created micro-defects at the surface. Meanwhile, fibers in the crystalline region may sustain most of the loads as creep load increases to a high level. Molecular chains in the fiber may rotate and elongate with high load. Elongated fibers were observed only at a high level of load. From the structural change as a function of applied load, a peak shift of crystal orientation was observed only in high load conditions by wide angle x-ray measurement. This may confirm that creep deformation could give rise to structure changes in EAPap.