PSI - Issue 64

Kun Feng et al. / Procedia Structural Integrity 64 (2024) 596–603 Kun Feng et al. / Structural Integrity Procedia 00 (2019) 000 – 000

598

3

2. Vehicle Bridge Interaction Model In this study, the bridge is modelled as a short-span concrete beam, with 15 m in length and 15 m in width, as depicted in Fig. 1. The specifics of its properties, as outlined in Table 1, are derived from prior research (González, Feng et al. 2023). The damping ratio, , in concrete bridge is not considered in this preliminary study. Concerning the finite element modelling approach, the beam is segmented into 15 finite beam elements, each characterized by 4 degrees of freedom. These include vertical translation and in-plane rotation at the end nodes of each element. Additionally, the bridge damage is modelled as Sinha’s crack model, adopted from (Sinha, Friswell et al. 2002).

Fig. 1. Vehicle bridge interaction model.

Table 1. Properties of the bridge. Parameter

Length, Width, Depth, ℎ

Value

Unit

15 15

m m m

Mass per unit length, 2nd moment of area, Modulus of elasticity, 1st, 2nd, 3rd Frequency, 1 ; 2 ; 3

0.75

28125 0.5273

kg/m

m 4

35

GPa

5.66; 22.62; 50.90 Hz The bus vehicle is simulated using a quarter-vehicle model, incorporating 2 degrees of freedom that account for the vertical movements of both the sprung and unsprung masses. The vehicle's specifications are based on research by Cebon in 1999 (Cebon 1999), while the bus's curb weight of 14300 kg is referenced from research work by McGrath et al. in 2022 (McGrath, Blades et al. 2022). Considering the bus's seating capacity, which comfortably accommodates up to 74 passengers without compromise, the operational weight of the bus is variable. It ranges from the base weight of 14300 kg, plus 75 kg for the driver, to an additional 68 kg per passenger, resulting in a total operational vehicle weight ranging from 14375 kg to 19407 kg, depending on the number of seated passengers.

Table 2. Properties of the vehicle. Parameter

Value 16900 15800

Unit

Vehicle Weight Sprung mass, Unsprung mass, Suspension stiffness, Tyre stiffness, Suspension damping, Tyre damping, 1st, 2nd Frequency, 1 ; 2

kg kg kg

1100

2 × 10 3

kN/m kN/m

3.5 × 10 3

40

kN s/m kN s/m

4

1.89; 11.35

Hz