目錄
摘要 1
Abstract 2
1 緒論 3
1.1 課題研究背景 3
1.2 國內外研究狀況 4
1.3 課題研究的目的及意義 6
2 曲軸三維造型的建立 7
2.1 Pro/E軟件簡介 7
2.2曲軸的設計 7
2.3 曲軸的簡化 10
2.4 曲軸實體建模 10
3 曲軸的自由模態(tài)分析 16
3.1 ANSYS Workbench簡介 16
3.2 整體曲軸有限元模型的建立 16
3.3 曲軸自由模態(tài)分析步驟 17
3.3 模態(tài)分析結果 20
4 結論 28
總結與體會 29
致謝 30
參考文獻 31

發(fā)動機曲軸三維造型及自由模態(tài)分析

摘 要

根據(jù)3108柴油機給定的參數(shù),依據(jù)經(jīng)驗公式,對曲軸的結構尺寸進行了一個新的改進設計,改變了平衡塊的形狀,并在其末端適當?shù)耐诹诵】滓詼p少曲軸的質量,改善曲軸的動平衡特性,然后基于Pro/E軟件，在適當?shù)暮喕瘲l件下，建立曲軸的三維模型，并利用ANSYS Workbench對曲軸在自由和約束兩種狀態(tài)下分別進行了模態(tài)分析，得出曲軸的前6階模態(tài)，即前6階固有頻率及其振型圖。結果表明，曲軸的固有頻率均高于工作轉速對應的頻率，不易產(chǎn)生共振；曲軸在低階頻率下，主要以彎曲模態(tài)為主,隨著階數(shù)的增長,變形也隨之增大,但變形發(fā)生的部位有所不同。通過模態(tài)分析的研究，為后續(xù)曲軸的動態(tài)響應分析奠定了堅實的基礎。
關鍵詞：曲軸，模態(tài)分析，頻率，振型
3D Modeling and Free Modal Analysis on Engine Crankshaft

Abstract

A new structure design of the 3108 diesel engine crankshaft was carried out according to the empirical formula and the original parameters, the design included the change of the balance block shape, dig holes in the end of the crankshaft in order to reduce the quality and improve the balance features, then the 3D model of three-cylinder diesel engine crankshaft was constructed based on Pro/E software in the appropriate simplified conditions. Two different model analysis on the freedom and constraint case were undertaken with the ANSYS Workbench, the results obtain the first six modals, included their inherent frequencies and the vibration modes of the fist six orders. The results showed that the inherent frequency of the crankshaft was higher than the frequency while the crankshaft is working, and it wouldn’t produce resonance easily; the crankshaft was mainly in bending modals during the low frequencies, and the deformation increased with the growth of the modes, but the deformation occurred in different parts. The mode analysis of the crankshaft made a solid foundation for the follow-up dynamic response analysis of the crankshaft.
Key words: crankshaft, modal analysis, frequencies, vibration modes