Abstract Light activated shape memory polymer (LaSMP) is one of novel shape memory polymers with dynamic strain and Young’s modulus when exposed to UV lights. This study investigates distributed microscopic control actions of LaSMP patches on hemispherical shells with free boundary. Based on strain models established in the experiments, governing equations of the spherical shell are defined and control forces in the meridional, circumferential and transverse directions are derived respectively. In case studies of LaSMP patch laminated on the shell by covering specific wavelength at each mode in the circumferential direction, the meridional and circumferential forces turn to zero. Then, the dominant transverse control forces and its components resulting from the bending moments and membrane forces are compared at different modes. Parametric analyses are carried out to evaluate the microscopic actuation effects of actuator position, thickness and shell radius, LaSMP thickness, etc. LaSMP induced meridional and circumferential microscopic membrane/bending control actions on hemispherical shells are evaluated. The analyses indicate that the transverse control forces increase with increasing of LaSMP patch thickness and decreasing of hemispherical shell thickness and radius. Then, the normalized control forces are derived by dividing LaSMP patch size. The parametric analyses confirm that the normalized control forces caused by membrane forces dominate the control effect and the best control position is near the boundary of hemispherical shell. This work provides an analysis procedure on estimating LaSMP vibration control actions and gives theoretical predictions for idealized LaSMP vibration control of hemispherical shells.

中文翻译：

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LaSMP 致动器对半球壳的微观控制作用

摘要 光激活形状记忆聚合物（LaSMP）是一种新型的形状记忆聚合物，在紫外光照射下具有动态应变和杨氏模量。本研究调查了 LaSMP 贴片在具有自由边界的半球壳上的分布式微观控制作用。在实验建立的应变模型的基础上，定义了球壳的控制方程，分别推导出了经向、周向和横向的控制力。在 LaSMP 贴片层压在壳上的案例研究中，通过在圆周方向的每个模式覆盖特定波长，经向力和圆周力变为零。然后，比较了不同模式下由弯矩和膜力产生的主要横向控制力及其分量。进行参数分析以评估致动器位置、厚度和壳半径、LaSMP 厚度等的微观驱动效果。评估 LaSMP 引起的对半球壳的经向和周向微观膜/弯曲控制作用。分析表明，横向控制力随着 LaSMP 贴片厚度的增加和半球壳厚度和半径的减小而增加。然后，通过划分 LaSMP 贴片大小得出归一化控制力。参数分析证实膜力引起的归一化控制力主导控制效果，最佳控制位置靠近半球壳边界。