Issue 70

S.K. Shandiz et alii, Frattura ed Integrità Strutturale, 70 (2024) 24-54; DOI: 10.3221/IGF-ESIS.70.02

is shown in Fig. 3. The schematic of the 6 Degrees of Freedom (DoF) TT assembly which will be used as a signal acquisition vehicle is shown in Fig. 4a. The dynamic equation of TT vibration can be written as follows:

Figure 3: Tractor and trailer (TT).

d [ ]{}[ ]{}[ ]{}{ }    T T T T M C K   d d F

(3)

The mass, damping, stiffness, and force matrices are presented in Appendix A.

c ₁ k ₁ k ₂ m ₂ m ₁ b ₁ b ₂ d ₁ m ₀

b ₃

v d ₂

u ₃ c t1 k t1 m t1 m t0 k t2 c t2 x ₃ m t0 k t2 c t2 x ₃ u ₃ c t1 k t1 m t1

d ₅ d ₆

c ₄ k ₄ c ₂

d ₃

d ₄

u ₁ c ₃ k ₃

r ሺ x ሻ

u ₂

x ₂

x ₁

L

c ₁ k ₁ k ₂ m ₂ m ₁ b ₁ b ₂ d ₁ m ₀

b ₃

v d ₂

d ₅ d ₆

c ₄ k ₄ c ₂

d ₃

d ₄

u ₁ c ₃ k ₃

r ሺ x ሻ

u ₂

x ₁

x ₂

L

Figure 4: Bridge and TT’s degrees of freedom in (Top) FEM, (Bottom) Modal Analysis Method.

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