旋轉式壓縮機之單一滑動葉片應力與疲勞分析

Analyses of Stress and Fatigue of a Single Sliding Vane for a Rotary Compressor

許碩哲(Shuo-Che Hsu)

指導教授 ： 黃元茂

國立臺灣大學/工學院/機械工程學研究所/碩士(2006年)

https://doi.org/10.6342/NTU.2006.01526

摘要

本研究探討單一滑動葉片旋轉式壓縮機之葉片的應力、疲勞損傷與疲勞壽命。當葉片運轉時所承受的負載，包括氣體壓縮時隨角度變化之氣體力、葉片本身因移動與轉動所造成的慣性力以及葉片與滑槽間、定子內壁等的接觸力。由於滑動葉片的所有負載之作用點以及邊界條件隨著葉片旋轉角度而改變，本文使用由彎曲力矩為出發點的一維樑理論，先求得上述所有負載作用下葉片各位置之彎曲力矩分佈，則可透過葉片截面積之性質求得該處彎曲應力之結果。另外，本文使用三維有限元素分析軟體ANSYS建構滑動葉片之三維模型，並建立正確之邊界條件與負載，以模擬葉片在承受負載後之應力結果，與樑理論在葉片橫截面上因彎矩所造成之正向應力做比較，以驗證樑理論所得結果的正確性。接著將有限元素軟體所得到之應力結果使用峰值法記數應力振幅的資料，再代入修正後之古德曼圖求得各應力振幅所對應之完全反覆應力與疲勞轉數，最後利用Morrow的塑性功交互破壞法則求得各應力振幅所產生之全反覆應力以及總和壽命所得到的疲勞壽命。當壓縮機轉子轉速為1500 rpm，滑動葉片大約在 循環即約為 小時的疲勞壽命時，累積的疲勞損傷程度將達到1；而疲勞破壞發生的位置，並非在葉片與滑槽間或定子內壁最常接觸的地方，而是發生在滑動葉片的中心位置。

關鍵字

應力 ； 疲勞 ； 滑動葉片 ； 旋轉式壓縮機

並列摘要

This study analyzes the stress, the fatigue life of the single sliding vane in a rotary compressor. When the compressor operates, forces acted on the vane including the force generated by air pressure, inertia forces produced during moving and rotating with the rotor and contact forces pressed by the stator inner contour and the slot of the rotor. Locations of loads acted on the vane and boundary conditions vary with angular locations of the sliding vane. The beam theory is used for the bending stress analysis of the vane. The finite element software ANSYS is used to generate a 3-D vane model with loadings and boundary conditions to calculate normal stresses on cross-sections of the vane, and the results are used to verify the bending stress calculated by using the beam theory. Subsequently, the stresses obtained from ANSYS are analyzed by the peak method to determine stress amplitudes and fatigue lives by the modified Goodman diagram. The plastic work interaction damage rule of Morrow is utilized to calculate the fatigue damage by each stress amplitude and the total fatigue life. When compressor rotates at 1500 rpm, the accumulated fatigue life is cycles or hours. The fatigue failure occurs at the center of sliding vane.

並列關鍵字

stress ； fatigue ； sliding vane ； rotary compressor

參考文獻

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