PSI - Issue 37

Rogério Lopes et al. / Procedia Structural Integrity 37 (2022) 81–88 R. F. Lopes et al./ Structural Integrity Procedia 00 (2019) 000 – 000

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identifying natural frequencies. Therefore, three types of damping configurations are taken into account identified as the normal, low and super rigidity state, as:

1. Low rigidity : 1.19366 × 10 3 ( . . . −1 ) 2. Normal rigidity : 1.19366 × 10 9 ( . . . −1 ) 3. Super rigidity : 1.19366 × 10 15 ( . . . −1 )

It must be mentioned that the smaller damping coefficient leads the structure to be more flexible compared to other configurations. The numerical analyses have been performed and the obtained results on the natural frequency are reported in Table 4. Referring to the acquired results, it can be inferred that different damping coefficients of the joint, in the dynamic behavior at the frequency level, do not reveal significant variation in the results. Since it is a viscous damping, the behavior of which is that the force is proportional to the velocity, and the bus is in static mode, therefore, the kneecap does not interfere with natural frequencies.

Table 4. Modes of vibration varying the coefficient of damping in the articulation.

1 ( ) 2 ( ) 3 ( ) 4 ( ) 5 ( ) 6 ( ) 7 ( ) 8 ( )

Damping configuration (Rigidity)

Capacity

0.4817 0.4817 0.4817 0.0000 0.0000 0.0000

0.9266 0.9266 0.9266 0.3901 0.3901 0.3901

Low

1.3487 1.3487 1.3487 0.5026 0.5026 0.5026

1.7553 1.7553 1.7553 0.9556 0.9556 0.9556

2.0661 2.0661 2.0661 1.6653 1.6653 1.6653

2.6404 2.6404 2.6404 2.0962 2.0962 2.0962

2.8368 2.8368 2.8368 2.4521 2.4521 2.4521

3.2929 3.2929 3.2929 2.7186 2.7186 2.7186

Normal Super

Null

Less

Normal Super

Full

a)

b)

c)

d)