Wuhan Universityof Technology11.1 Analysis of vibration freguenciesU, = 1U=1U,=11.0kip.sec/inUk= 600k12=-600k13=0600kips/in1.5U2k21=-600k22=1,800k23=1,2001,2002.0U3k32=—1,200k33=3,000k31=01,800(a)(b)FIGUREE11-1Frameusedinexampleofvibrationanalysis:(a)structuralsystem;(b)stiffnessinfluencecoefficients4-6
4-6 Wuhan University of Technology 11.1 Analysis of vibration frequencies FIGURE E11-1 Frame used in example of vibration analysis: (a) structural system; (b) stiffness influence coefficients
Wuhan University of Technology11.1 Analysis of vibration freguencies0[1.00001.5m=(1kip·sec2/in)002.0]-103-2-1k=(600kips/in)0-25]1-B-10k-w2m=(600kips/in)3-1.5B-2-10-25-2B2B-6004-7
4-7 Wuhan University of Technology 11.1 Analysis of vibration frequencies
Wuhan University of Technology11.1 Analysis of vibration freguenciesB3-5.5B2+7.5B-2=0B1 = 0.3515B2= 1.6066.B3=3.5420210.8814.522W1we963.9631.048rad/secw2w2,125.2046.100w34-8
4-8 Wuhan University of Technology 11.1 Analysis of vibration frequencies
Wuhan UniversityofTechnology11.2 Analysis of vibration mode shapesEE(n)=飞-wmForthispurposeitwillbeassumedthatthefirstelementofthedisplacementvector has a unit amplitude; that is,0in02n02n03n03n.:UNN4-9
4-9 Wuhan University of Technology 11.2 Analysis of vibration mode shapes For this purpose it will be assumed that the first element of the displacement vector has a unit amplitude; that is