CRH2动车组轴箱弹簧疲劳试验方案研究

　[收稿日期]2008206214

　[作者简介]宁晓丹(19832),女,2006年大学毕业,硕士生,现主要从事车辆零部件的现代设计理论与方法方面的研究工作。C RH 2动车组轴箱弹簧疲劳试验方案研究

宁晓丹,孙保卫,商跃进,王　红　(兰州交通大学机电工程学院,甘肃兰州730070)

[摘要]在现有机车车辆圆柱螺旋弹簧试验标准的基础上,针对CR H2动车组轴箱弹簧的特点,利用疲劳理论确定了该弹簧的疲劳试验方案,即在弹簧表面质量完好的情况下,疲劳试验次数达到300万次后,弹簧未发生断裂,可判定其合格。研究表明,该方案可以作为CR H2动车组轴箱弹簧进行产品质量检验的疲劳试验依据。

[关键词]动车组;轴箱弹簧;疲劳试验;疲劳寿命

[中图分类号]U26014[文献标识码]A [文章编号]167321409(2008)032N258202

随着铁路客车第6次大提速,动车组在我国许多线路上得到了广泛应用,这使得研究如何对其零部件进行试验评价的问题提到议事日程上来。为此,笔者针对CR H2动车组轴箱弹簧的疲劳试验方案进行可行性分析。

1　试验方案确定依据

铁路车辆采用的圆柱压缩螺旋弹簧通常按TB/T221121991进行疲劳试验。按式(1)确定试验载荷P ,达到规定的试验次数N 后,未发生断裂者,判定其为合格。可见试验方案取决于动荷系数K 和试验次数N 。

P =(1±K )・P m

(1)

式中,P m 为作用于弹簧上的垂向静载荷;K 为动荷系数。2　试验参数确定

211　动荷系数确定

表1　常数a 、b 、c 、d 的取值a 簧上簧下b c 簧上簧下d 货车客车1153150105014270156911653

TB/T133521996《铁道车辆强度设计及试验鉴定

规范》规定车辆零部件的动荷系数计算公式为:

K dy =a +bV f j +dc f j (2)式中,V 为车辆构造速度;f j 为静挠度;a 、b 、c 、d 为常数,按表1取值。

212　试验次数确定

为了保证试验方案的有效性,试验次数应该大于等于弹簧的设计寿命。由疲劳理论可知弹簧的设计寿命为:

N =[τ-1]τ-1d

m ・N 0(3)式中,[τ-1]为对称循环下的许用应力;τ-1d 为对称循环下的当量应力;m 为材料常数,m =4～8,通常取

m =5134;N 0为循环基数。

由文献[1]和[2]可知:

τ-1d =(K +012)・τm ≤[τ-1]

(4) τm =8・P m ・D ・βπ・d

3(5)

・852・长江大学学报(自然科学版)　

2008年9月第5卷第3期:理工Journal of Yangtze U niversity (N at Sci Edit)　Sep 12008,Vol 15No 13:Sci &Eng

式中,τm 为平均应力;d 为簧条直径;D 为平均直径;β为应力修正系数,β=4m -14m -4+01615m

;m 为弹簧指数,m =D/d 。

3　CRH 2动车组弹簧疲劳试验方案

311　动荷系数确定

CR H2动车组营业最高速度V =200km/h ,满员时,每组内簧和外簧的总载荷为P m =5818kN ,则静挠度f m =4613mm ;由式(2)可得动荷系数K =0144,由于制定公式的工况与目前铁路现状有很大差异,所以疲劳试验时取动荷系数K =015。由式(1)得,试验载荷为2914～8812kN 。312　试验次数确定

将试验载荷和弹簧的基本参数(见表2)代入式(5),得到内簧的应力为435162M Pa ,外簧的应力为442192M Pa ,可见只要外簧通过疲劳试验,在理论上内簧也可以通过试验。因此,笔者取外簧的应力进行分析计算。

表2　弹簧参数

弹簧类型

簧条直径d /mm 平均直径D /mm 自由高H /mm 刚度C /N ・mm -1外簧

4122025691511内簧2614324035512

不同钢厂生产的弹簧钢的质量存在着差异,同一钢厂不同批次的弹簧钢质量也不稳定,另外各弹簧厂在生产弹簧的质量控制上也有差异。不过,经过多次疲劳试验发现,当τ-1d ≤

305M Pa 时,用60Si 2CrVA T 弹簧钢制成的弹簧基本上都可以通过300万次的疲劳试验。故取[τ-1]=305M Pa ,N 0=300万次。另外,由式(4)得弹簧的当量应力为31011M Pa 。将上述数据代入式(3)可得弹簧的设计寿命为275万次。为了提高对弹簧制造质量的要求,取试验次数N =300万次。

4　结 语

笔者在现有机车车辆圆柱螺旋弹簧试验标准的基础上,针对CR H2动车组轴箱弹簧的特点,利用疲劳理论确定了该弹簧的疲劳试验方案,即通过合理选取动荷系数以确定试验载荷P 后,对CR H2动车组轴箱弹簧进行疲劳试验,达到规定的试验次数300万次后,未发生断裂者,判定其为合格。该方案可以作为CR H2动车组轴箱弹簧进行产品质量检验的疲劳试验依据。

[参考文献]

[1]商跃进,王红1铁路货车变刚度弹簧组疲劳强度设计方法研究[J ]1机械强度,2006,28(1):141～1451

[2]严隽耄1车辆工程[M ]1北京:中国铁道出版社,19991

[编辑]　易国华

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952・第5卷第3期:理工宁晓丹等:CR H2动车组轴箱弹簧疲劳试验方案研究　

as secure as it was reckoned1It may be insecure under particular conditions1In order to perfect t heir security we brought forward a new cryptoanalysis met hod2only lengt h attack aiming at t he limita2 tions of one2time system1At t he same time,new means to attack protocols of quant um cryptograp hy and t he modified quant um encrypt protocol equipped wit h correcting codes and monitor measure are propo sed1

K ey w ords:one2time system;quant um cryptograp hy;cryptograp hy;perfect secrecy

229Three W ay H andshakes B ased on Self2certif ied of Public K ey

WANGLin2jie,H AN Chun2xia　(Tong ren College,Tong ren554300)

Abstract:First,a self2certified signat ure based on p ublic key crypto system was p ropo sed1In t his scheme,a user anonymously f ulfills identity registration wit h t he protocol of user registration,and get s t he certificate of p ublic key generated from CA and t he user1Based on t his certificate,t he p ublic key of a user can be comp uted1The bot h end users of handshaking can finish t he verification of p ub2 lic key for each ot her wit h t he protocol of self2certified of p ublic key1The receiver of message can recover t he original message based on t he signat ure1Therefore,t he propo sed signat ure scheme has i2 dentity aut henticated and message confidentiality1Second,generates a secret handshake making use of a scheme1In a secret handshake protocol,an honest member in t he group never reveals his group af?liation unless t he ot her party is a valid member of t he same group1If a handshake between two parties fails,t he identity of eit her party is not disclosed1

K ey w ords:self2certified of p ublic key,aut henticated encryption scheme,privacy key,handshake, key exchange

244Study on22Cr2duplex Stainless Steel Corrosion R esistance of U niform in Different Acid Media FAN Y u2guang LI N H ong2xian　(X i’an S hi you Universit y,X i’an710065)

Abstract:The22Cr2duplex stainless steel and ordinary austenitic stainless steel316L were st udied on uniform corrosion of by means of electrochemical met hods in HCl and H2SO4solution,in50% HAC solution co ntaining formic acid,in t he p ho sp horic acid containing H F and choride ions1The result s show t hat22Cr2duplex stainless steel corro sion resistance of uniform is better t han316L austenitic stainless steel1

K ey w ords:22Cr2duplex stainless steel;uniform;corro sion;elect rochemical met hods

255Finite Element Analysis and Optimized Design to Large2scale Sphere T ank

ZH ANG Zhi2liang　(S out hwest Pet roleum Universit y,Cheng du610500)

LE NG X i　(X inj iang Pet roleum A dminiat ration B ureau,Karamay834000)

HOU Y ong2jun　(S out hwest Pet roleum Universit y,Cheng du610500)

Abstract:It used t he finite element met hod to analyze and optimize t he design of t he large2scale sp here tank,and st ress assessment1At t he same time,t he top pillar height,pallet t hickness and t he cylinder wall t hickness are optimized and designed1

K ey w ords:Sp here tank;finite element;design optimization

258R esearch on the F atigue T est Project of Axle Box Springs Used for CRH2Multiple U nits NI NG X iao2dan,SUN Bao2wei,SH ANG Y ue2jin,WANG H ong　(L anz hou J iaotong Universit y,L anz hou730070)

Abstract:Based on existed fatigue test specification of the cylindrical screw springs and the features of axle box Springs used for CRH2Multiple Units,the fatigue test project is present by using the fatigue theory1In the complete quality of the spring surface and after the number of fatigue test reaches to300million,the springs can be judged when they are not broken1The research indicates that the plan can be used for inspec2 ting product quality of axle box springs based on the fatigue test project1

K ey w ords:multiple unit s;spring;fatigue test;fatigue life

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