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IP屬地：北京 上傳時間：2023-06-25 格式：DOCX 頁數(shù)：42 大?。?71.61KB 積分：12 舉報 版權(quán)申訴

m2f+m2r+m2c=m2f+m2r+m2c= =mr2= a2+m2ry 2 y2my2r2m 2 yr2andpitchvibration"j" simplifyto nemodel4doms：2wheels,sprungmassdistributionr2懸掛質(zhì)量分配系數(shù)：ee＝1connectionmass聯(lián)系質(zhì)量m2cTheverticalmovementofm2fandareindependent.Two domsdoms：onewheelDualmassvibration mur

mufSinglemassvibrationff<5Hzdeflectionoftyreissmall(ft:wheelnaturalfrequency車輪固有頻率,ft10~15HZSinglemassvibrationsys. VibrationofSingleMasssecond-orderequationwithconstantC(z-q)+K(z-q)= assume:assume:2n=Cmw20=2m2w0systemnaturalcircularfrequencyf=w0=K0m2ratio阻尼比，zn=w0 m2K00

2z= belongtosmall\z=Ae-

w

-n2t+a0wr:systemnaturalfrequencywith0有阻尼固有頻率,w=w2 vibrationscopeattenuationaccording e-nt振幅按e-nt衰減AttenuationAttenuationvibration衰減振動曲線AttenuationAttenuationvibrationinfluencedbywrwr=w2-n2＝w00z?wr z＝1wr＝0bigdampnovibration大阻尼時系統(tǒng)不振動z?0.25w0-wrw?3％r00有阻尼后振動頻率變化不大AttenuationvibrationinfluencedbydA1 d=A1

Ae-

=

=e1-z2 Ae-n(t1+T2Measuredξby Measuredξby0nT= = 011+4p2/ln2(dfix

wr=1-z

w1- 1- (x?dFourierFouriertransformationf(t)=differentiationFdnf(t)n=(jw)F(w)n3.Frequencyresponsecharacteristicsofsinglemass+w20 =+w0 fiz(f時域z(t)3.Frequency3.Frequencyresponsecharacteristicsofsinglemass differential 對運(yùn)動微分方程(jw)2z(w)+2n(jw)1z(w)+w2z(w)=2n(jw)1q(w)+w2q(w) -w2+j2nwz(w)=w2+j2nw z(w) w2+q(w)=(w2 0w2)+-0f(t)=dnf(t)F =(jw)nF(w)(dt)n 3.Frequency3.Frequencyresponsecharacteristicsofsinglemassinput輸入q(t) 0(w2-w2)+0w2+=z(w)q(w)0(w2-w2)2+(2nw)0(w2)2+=3.Frequency3.Frequencyresponsecharacteristicsofsinglemass0w00

= 1+2

z(w)

2+wq(w) w

)+

-w2)+0z(w)0q(w)

1+(1-l2)2+l)2

z(w)

(w2)2+00(w2-w2)2+00powerpowerspectrumofscopefrequencycharacteristics?powerspectrumof輸出的功率譜幅頻特性2?ysisysisofscopefrequencyz(w)q(w)

1+(1-l2)2+l)20111012λ=ω/ω=1+(1-l2)2+l2ysisofscopefrequency(LF0z?dynamiccharacteristisysisysisofscopefrequency5l<x=

w0010111012λ=ω/ωz(w) (1-l2)2+1+x?，peakvaluez(w)ysisysisofscopefrequency高頻區(qū)：l>Zx

z(w)0111012λ=ω/ω=1+(1-l2)2+l2=wq(w)

z(w)

z(w)=wq(w) q(w)=q(w)

z(w)q(w)

z(w)q(w)f(t)=F fnnn=(jw)F4.Response4.Responsetoroadsurfacerandominputofsinglemassndn4.Response4.Responsetoroadsurfacerandominputofsinglemass(1)(1)G(f)=G(f2q(2)G(f)fd2w)G(fqF2(3)G(f)= G(f dGq2GG(f)q(w)G(f)=wq2z(w)q(w)2z(w)q(w)G(fqG(f)G(f)=ww2G(fqG(f)G(f)2z(w)q(w)w4G(fq\G(f)=w2G(fqqG(f)=w4G(fqqG(f)=w2G(fqqGG(fq=q=1u1uG(n)q1uG(nq0nn)0G(fG(n2q001f=n=u\G(fq=G(n)n2q00f(f)=(2pf)2G(n (f)=G(n)n2u(2p)4 (f)=G(n)n2u(2p21f=G(n)n2u(2p G(f)=G(n)n2u(2p G(f)=G(nw (f)=G(n)n2u (f)=w2G(fq(f)=w4G(fqfG(f)=w2G(f 4.Response4.Responsetoroadsurfacerandominputofsinglemass

424G(f)=w22

2

2

f4.Response4.ResponsetoroadsurfacerandominputofsinglemassG(f)=w2

G(f)

G(nu(p)

f)

G(n f)

f)

G(nuw) Gq(fGq(f)white

w z(w)z(w

similargraph

z(w)q(w)

1+(1-l2)2+pointof

G(f

w1+

sw1+

flwfl-mainmeasure主要措施flflw0=2p

=2f0=1.1~1.5zcar），f01.5~2ztruck、crosscountry xneed:w0flm2

Km2andneed:x?m2\m1flm24.Response4.ResponsetoroadsurfacerandominputofsinglemassFd==z/g=1 4.Response4.ResponsetoroadsurfacerandominputofsinglemassAffd(w)=z(w)-q(w)=z(w)q(w) q(w) 1+2

1(1-l2+2 f(w) q(w)

(1-l2)2+ Gfd

(f)

fd(w)q(w)

Gq(f)

fd(w)

Gq(f (f)

fd(w)

G(f)=

fd(w)

G(f

wq(w) Gq(f)——whitenoisef(w l2 dd

1

w(1-l2)2+dw0 ?fdd

w

x? G(f)=wfdG(f)=wfd(w)q(w)G(fx?,

w0 ?,fddx?,fdddynamicdeflectionstatic

d 1fd

m2 wK0 wK0f=m2g

static \fd

note:Originofznote:Originofzisonstaticequilibriumiffd=fdneed:fd<fd為KC，車身的垂直位移為z，輸入的路面不平度函數(shù)為q，路2m，路面不平度系數(shù)為輸入功率譜輸入功率譜: (f)q1uGq(n )n- n=3