摘要
本研究針對圓柱旋轉壓縮成形，考慮不同之摩擦型態(定剪摩擦、庫倫摩擦、混合摩擦)，分別以切片法、上界限法及有限元素法加以分析探討旋轉壓縮成形特性，其中切片法、上界限法(只限定剪摩擦)可建立理論解析模式、商用有限元素軟體(SUPERFORM)可進行有限元素模擬並求得最佳外形之壓縮參數，並可從有限元素模擬中求得等效應力、等效應變、速度場、圓柱鼓起外形、壓縮負荷及扭轉扭矩等壓縮特性，最後以實驗加以驗證分析模式之適用性。因圓柱在旋轉時被壓縮，除在徑向有變形外，在周向亦有扭轉變形，故在徑向摩擦剪應力與周向摩擦剪應力之間會產生摩擦角( )，因此解析模式將比無旋轉之壓縮成形更為複雜。本研究有系統地探討不同壓縮條件，如摩擦因子(或摩擦係數)、旋轉角速度、幾何外觀比、塑流應力、摩擦因子比(或摩擦係數比)等，對於壓縮特性之影響。並藉由切片法、上界限法、SUPERFORM模擬分析及實驗結果相互驗證，以驗證旋轉壓縮成形之可行性與實用性。本研究可應用於圓柱工件之預鍛及扣件旋轉鍛造，未來更可用於精微成形以減少晶粒尺寸大小。
並列摘要
This study aims at the rotating compression forming of cylinder considering different frictional type (constant shear friction, coulomb friction, hybrid friction) to use the slab method, upper bound method and finite element method respectively to investigate and analyze the rotating compression; slab method and the upper bound method (only suitable for forming constant shear friction) can be used to establish the theoretically analytical model, a commercial FEM (SUPERFORM) software can be used to perform FEM simulation and find the compression parameters of optimum shape. Besides, the compression characteristics, such as equivalent stress and strain, velocity field, bulging shape of cylinder, compression force and rotating torque etc, can be obtained from the FEM simulation. Finally, the acceptance of analysis model has been verified from the experiment. Under the rotating compression of cylinder, in addition radial direction deformation, circumference direction has the twist deformation, Therefore, the frictional angle( ) is occurred between the frictional shear stress of radial direction and that of the circumference direction, the analytical models are more complicated in comparison with that without rotating. Furthermore, the effects of frictional factor (or frictional coefficient), rotating angular velocity, aspect ratio, flow stress, and frictional factor ratio (or frictional coefficient ratio) on the compression characteristics are explored systematically. The feasibility of and practicability of the rotating compression of cylinder can be verified by performing the comparison among the theoretical analysis based on the slab method and the upper bound method, the simulation analysis based on SUPERFORM software, and experimental results. This study can be applied to the perform of cylinder and rotating forging of fasteners. In the near future, the rotating compression forming can be used in the micro-meso forming to reduce the grain size.
參考文獻
延伸閱讀
- 鄒國益、成清吉、黃敏郎（2007）。圓柱扭轉鍛造成形之研究。鍛造，16(2)，5-12。https://doi.org/10.29791/Forging.200707.0002
- 李榮顯、陳彥儒、王水鐸（2004）。利用凹槽設計於圓柱鍛粗試驗之可行性探討。鍛造，13(4)，29-34。https://doi.org/10.29791/Forging.200411.0001
- 陳正修（2020）。有限長多圓柱流場實驗之研究〔碩士論文，國立臺灣大學〕。華藝線上圖書館。https://doi.org/10.6342/NTU202003476
- 梁鈞凱（2014）。Material Characterization Using Cylinder Cavity with Different Mode〔碩士論文，國立清華大學〕。華藝線上圖書館。https://www.airitilibrary.com/Article/Detail?DocID=U0016-2912201413534228
- 曾博駿（2008）。Design and testing of a couette-flow system with rotating outer cylinder〔碩士論文，淡江大學〕。華藝線上圖書館。https://doi.org/10.6846/TKU.2008.01037