使用ANSYS之機械結構動態分析

Dynamic Analyses for Machine Structures by using ANSYS

蘇崑熙(KUN-HIS SU)

指導教授 ： 康淵

中原大學/工學院/機械工程研究所/碩士(2003年)

https://doi.org/10.6840/cycu200300648

摘要

中文摘要
本研究探討工具機結構設計與結構剛性之特性。磨床結構與線馬磨床是由工作台、鞍座、軌道及底座構成。將次結構組合成整機，在整機分析時以有限元素法，使用ANSYS軟體，探討其共振頻率、模態形狀、動剛度等動態分析。
工具機所引起振動主要因素為外力激振與自激激振。因結構設計不當，造成工具機在切削時所產生不穩定顫振，使工件表面會產生波紋。外力激振所造成的原因可藉由人力改善，而自激激振所造成的原因必須藉由結構設計來改善。因此改善自激激振的先決條件，可藉由工具機整機結構的動態分析結果，來完成結構設計。
因此，本研究使用商用軟體ANSYS來建立有限元素分析模型，離散化網格，求解工具機整機結構之動態分析，經由模態測試所求得之頻率值作相互比對，以驗證分析結果與實驗值之準確性，並依其差異性進行探討、修模及參數校正。

關鍵字

模態分析 ； 動態分析 ； 有限元素分析 ； 磨床 ； 工具機 ； 模態測試 ； 結構設計

並列摘要

ABSTRACT

The research investigated the characteristics of machine tools structural design and structural stiffness. Grinder structural and linear motor grinder are composed from bench, saddle, track and base, then composed the substructure to the complete structure. When doing the complete structure analysis, using the ANSYS software in the finite element to investigate the resonant frequency, mode shape, dynamic stiffness and dynamic analysis.
The major factors to make machine tools vibration are external excitation and self-excitation. Because of the structural design is not well done, causing the unstable vibration when machine tools are cutting and make the ripple on the surface of the work piece. The effect that external excitation make can improve by manpower, however the self-excitation should through structural design. So, the primary condition to improve the self-excitation, can through the dynamic analysis result for complete structural of the machine tools to finish the structure design.
Therefore, the research is using ANSYS software to establish the finite element model, discrete and solving for the dynamic analysis of machine tools. Then compare with the frequency value that got form the model testing. To prove the analysis result and experiment value accuracy, and according to its difference to proceed investigate, revise model and correct parameter.

並列關鍵字

Mode analysis ； Structural design ； Grinder ； Machine tools ； Dynamic analysis ； Finite element model ； Modal testing

參考文獻

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5. D. J. Dawe, "Matrix and finite element displacement analysis of structures," Clarendon Press, 1984.