楊光 任尊松 孫守光
摘要: 輪對彈性變形和旋轉(zhuǎn)振動對輪軌系統(tǒng)運行安全性影響需要從理論上進行深入研究。利用ANSYS有限元分析軟件對輪對彈性化處理后,在SIMPACK多體動力學(xué)軟件中建立了包含高速旋轉(zhuǎn)彈性體輪對的車輛系統(tǒng)動力學(xué)模型。采用數(shù)值方法,得到了輪軸彈性彎曲變形量以及不同軌道不平順激擾下輪對垂向振動加速度響應(yīng)等。結(jié)果表明,考慮彈性和旋轉(zhuǎn)振動后,輪對車軸發(fā)生彎曲變形效應(yīng)明顯且中部變形量最大,車輛運行速度對車軸彎曲變形量和輪軌附加動力有一定的影響,輪對垂向振動加速度頻譜出現(xiàn)與旋轉(zhuǎn)速度相關(guān)的頻率特征。本文方法和結(jié)果對揭示輪對真實運動特征和研究高速輪軌安全性具有良好的指導(dǎo)意義。關(guān)鍵詞: 彈性輪對; 高速列車; 旋轉(zhuǎn); 頻率特征
中圖分類號: U260.331+.1文獻(xiàn)標(biāo)志碼: A文章編號: 10044523(2016)04071406
DOI:10.16385/j.cnki.issn.10044523.2016.04.019
引言
近年來,中國穩(wěn)步發(fā)展高速鐵路,高速動車組運營速度已到達(dá)300 km/h。作為列車走行的關(guān)鍵部件,高速旋轉(zhuǎn)輪對運用安全性受到了高度關(guān)注與重視,亟需在高速范圍內(nèi),對旋轉(zhuǎn)輪對發(fā)生彈性變形后引起的輪軌接觸、走行關(guān)系、輪軌附加動力以及車輛系統(tǒng)振動和運行安全性等問題開展深入研究。傳統(tǒng)車輛動力學(xué)研究工作中,輪對一般考慮為剛體或者輪對僅向前做平移運動,無法體現(xiàn)出輪對高速旋轉(zhuǎn)過程中的彈性變形及其對結(jié)構(gòu)振動的影響。近年來,國內(nèi)外關(guān)于輪對彈性化后車輛系統(tǒng)振動特性的研究逐漸增多。萬鵬等[1]分別將輪對考慮為剛性和彈性建立整車模型,得到了輪對彈性化處理以后車輛臨界速度較剛性輪對的值有所降低的結(jié)論;張永貴[2]研究發(fā)現(xiàn),在針對輪軸振動特性的分析中,采用彈性輪對比采用剛性輪對時得到的計算更加準(zhǔn)確,也更符合實際情況;馬衛(wèi)華等[3]通過加大輪軸彎曲剛度來改善輪對的垂向振動和輪軌垂向力,以實現(xiàn)改善輪軌動態(tài)接觸狀態(tài)的目的;張寶安[4]提出彈性輪對的結(jié)構(gòu)振動對輪軌接觸點位置,蠕滑率蠕滑力和脫軌因數(shù)等均產(chǎn)生較明顯的影響;劉韋等[5]研究表明,輪對考慮為彈性體將會更加準(zhǔn)確地反映出車輪多邊形化對輪軌力的影響;Baeza L等[6]對比分析彈性旋轉(zhuǎn)輪對模型和剛性輪對模型在車輪扁疤,軌道不平順激擾下的輪軌力差異。但是,在既有研究中,對于輪對彈性化處理以后,車軸彈性彎曲變形對高速旋轉(zhuǎn)輪對自身振動特性方面的研究尚未涉及。
有鑒于此,本文以某型高速動車組為對象,研究彈性輪軸彎曲變形特征,并進一步分析彎曲變形對高速旋轉(zhuǎn)輪對振動特性的影響。為避免彈性構(gòu)架[7]和彈性車體[89]對輪對垂向加速度頻率成分的影響,這里僅將輪對處理為彈性體,建立剛彈耦合車輛系統(tǒng)動力學(xué)模型。
Abstract: Further theoretical studies are needed about the influences of elastic deformation and rotation vibration of wheelset on the wheelrail system operation safety. The railway vehicle system with the highspeed rotating wheelsets which were considered as elastic bodies with the FEM is established in the SIMPACK software. With the numerical method, the degree of bending deformation of the axle is achieved while the wheelset was considered as the elastic body, and the vertical vibration acceleration response of the wheelset under different rail irregularity excitation is also obtained in this paper. The results show that, while considering the elastic and rotation vibration, the axle bending deformation effects are obvious, and the maximum deformation occurs in the center. The degree of bending deformation and the additional force of wheel rail are affected by the vehicle operation speed. The frequency characteristic associated with the speed of rotation appears in the spectrum of vertical acceleration of the wheelset. The methods and the results in this paper have guiding significance to the real characteristics of the wheelset rotation and the studies on the highspeed wheel rail safety.
Key words: elastic wheelset; highspeed train; rotation; frequency characteristics