光學機構之動態特性與模態分析

Dynamic Characteristics and Modal Analysis of an Opto-Mechanical Structure

陳怡呈(Yi-Cheng Chen) ； 李良愷(Liang-Kai Lee)

《科儀新知》 149期 (2005/12) Pp. 57-66

https://doi.org/10.29662/IT.200512.0007

摘要

光學機構必須具備一定的靜態與動態結構穩定性，以保持光學元件之間的相對位置並維持整體光學系統的成像品質，本研究使用有限元素分析，針對一光機模組進行模態分析與剛性改善。首先利用振動試驗機進行整體光機結構之正弦掃描振動測試，找出光機結構的動態特性與共振頻率，然後建立與試驗結果相符之有限元素分析模型，進行有限元素模態分析與設計改進，包含主結構的分析與改善，以及次鏡支撐樑之分析與改善，最後提出提升共振頻率與改善結構剛性之可行方案。

並列摘要

Optical mechanisms must possess static and dynamic stability to maintain relative positions between optical components and to ensure the image qualities of optical systems. Based on finite element analyses, this study applies modal analyses to improve the rigidity of an opto-mechanical structure. Firstly, a swept sine vibration test is performed to study the dynamic characteristics and natural frequencies of the opto-mechanical structure. Then, a reliable finite element model is built, based on which finite element modal analyses are performed to improve design parameters. Finite element modal analyses of the main structure and the secondary mirror support beam are performed to improve their rigidity, respectively. Finally, feasible solutions are proposed to attain an increased natural frequency and improved rigidity.