組合式可變螺距複合材料螺槳之結構設計與分析

Structural Design and Analysis of a Replaceable Blade and Adjustable Pitch Composite Marine Propeller

本文發展一新型的複合材料組合可變螺距螺槳，進行設計、製造、測試、分析及改良等工作。以二個小型船舶使用的舷外機螺槳為分析對象，在可組合螺葉及可改變螺距的條件下，進行CAD設計並轉換成CNC切削資料，製作射出成形模具，並完成複合材料組合可變螺距螺槳原型，使用的軟體包括I-Deas、Ansys和PSF2。採用之基材材料為Nylon、PPS及GV-5H，為配合射出成型，加強材採用2mm短纖玻璃纖維，其中Nylon及PPS應用在螺槳一上，GV-5H則應用在螺槳二上。依螺葉單點受力測試結果顯示，Nylon螺槳有變形太大缺點，PPS螺槳雖然剛性較高，但極限應變太小，容易發生脆性破壞，GV-5H的強度遠高於Nylon及PPS，是三者中較適合應用在複合材料組合可變螺距螺槳者。此外，在分析方面，分別採用PSF2與ANSYS於螺槳流力負荷及結構計算，並探討加寬螺葉與螺轂連接長度、增加螺葉厚度及採用較高強度材料來改進複合材料螺槳強度。 A new type of replaceable blade and adjustable pitch composite marine propeller was developed in this paper. Two small out board propeller were considered in the analysis. Works of development includes design, manufacture, testing, analysis and structural improvement. The softwares, I-Deas, ANSYS and PSF2, were used in the CAD, structure and fluid numerical evaluation. Designed data was transfer to CNC cutting machine to produce three injection molds for the manufacture of parts of composite propeller. Matrix of Nylon, PPS and glass fiber with 2mm length were used in the first propeller. The so called GV-5H material was used in the second propeller. A simple one-point loading test was applied in the structural testing of composite propeller blade. It is found that too much deflection occurred in the Nylon propeller and too brittle in PPS propeller, though all in safety. However, the strength of GV-5H propeller is the best of these three. Increasing of connecting area of blade and hub and the thickness of blade were analyzed to improve the strength of composite propellers.