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JETRO G. SARAJENA STE 224- STRUCTURAL DYNAMICS 2-λ 2-λ 2-λ -1 1-λ -1 2-λ - -1 -1 -1 1-λ 0 + 2-λ -1 2-λ -1 1-λ -1 - -1 -1 1-λ 0 + -1 2-λ 2-λ -1 1-λ -1 - -1 -1 -1 1-λ 0 + 1 1 0 2-λ -1 1-λ -1 - -1 -1 -1 1-λ 0 =0 2-λ 2-λ 1-λ -1 + 1 2-λ 0 -1 1-λ + 2-λ -1 2-λ 1-λ -1 + 1 2-λ 0 + -1 2-λ 2-λ 1-λ -1 + -1 1 -1 1-λ + 1 0 2-λ 1-λ -1 + 1 1 0 =0 λ 5 simplifying the equation we got a polynomial into 5th degree. -9λ 4 +28λ 3 -35λ 2 +15λ -1=0 Using Synthetic Division, Solve for λ: λ = 0.081 1 λ = 0.690 2 λ = 1.715 3 λ = 2.831 4 λ = 3.682 5 mh³ λ= ω² 12EI λ = 0.081, ω=15.60 rad/s 1 λ = 0.690, ω=45.55 rad/s 2 λ = 1.715, ω=71.81 rad/s 3 λ = 2.831, ω=92.25 rad/s 4 λ = 3.682, ω=105.22 rad/s 5 Solve for the First Mode: [k-ω²m]θ =0 1 2-λ 2-λ 2-λ 2-λ 1-λ -1 -1 -1 -1 -1 -1 -1 -1 0 0 0 0 0 0 0 0 0 0 0 0 =0 θ θ θ θ θ 1 2 3 4 5 using λ = 0.081, we have 2-λ 2-λ 2-λ 2-λ 1-λ -1 -1 -1 -1 -1 -1 -1 -1 0 0 0 0 0 0 0 0 0 0 0 0 = θ θ θ θ θ 11 12 13 14 15 1.919 -1 -1 1.919 -1 1.919 0.919 -1 1.919 -1 -1 -1 -1 0 0 0 0 0 0 0 0 0 0 0 0 = θ θ θ θ θ 11 12 13 14 15 0 0 0 0 0 0 0 0 0 0 6

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  • JETRO G. SARAJENASTE 224- STRUCTURAL DYNAMICS

    2- 2- 2- -11--12- - -1-1 -1

    1- 0 + 2- -12- -1

    1--1 - -1-11- 0 + -1 2-

    2- -11--1

    - -1 -1 -11- 0 + 1 1 0

    2- -11--1 - -1

    -1 -11- 0 =0

    2-. 2- 1- -1 + 1 2-.

    0

    -1 1- + 2- -1 2- 1- -1 + 1 2- 0 + -1 2- 2- 1- -1

    + -1 1 -1 1- + 1 0 2- 1- -1 + 1 1 0 =0

    5simplifying the equation we got a polynomial into 5th degree.

    -9 4+283-352+15-1=0Using Synthetic Division, Solve for :

    = 0.0811 = 0.6902 = 1.7153 = 2.8314 = 3.6825

    mh = 12EI

    = 0.081, =15.60 rad/s1 = 0.690, =45.55 rad/s2 = 1.715, =71.81 rad/s3 = 2.831, =92.25 rad/s4 = 3.682, =105.22 rad/s5

    Solve for the First Mode:[k-m] =01

    2-2-

    2-2-

    1-

    -1-1 -1

    -1 -1-1 -1

    -1

    00 00 0

    00 00 0 0

    0 =0

    12345

    using = 0.081, we have

    2-2-

    2-2-

    1-

    -1-1 -1

    -1 -1-1 -1

    -1

    00 00 0

    00 00 0 0

    0 =

    1112131415

    1.919 -1 -1 1.919

    -11.919

    0.919

    -11.919 -1

    -1-1-1

    0 0 0 0 0

    0 0 0 0 0 0 0

    =

    1112131415

    00000

    00000

    6