PSI - Issue 37

Behzad V. Farahani et al. / Procedia Structural Integrity 37 (2022) 668–675 Behzad V. Farahani et al./ Structural Integrity Procedia 00 (2021) 000 – 000

670

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Figure 1. Geometry of the studied bus section respecting the material definition.

Table 1. Material properties.

Young’s modulus [ ] = 69500 = 210000

Density [ / ] = 2.7 × 10 −9 = 8.05 × 10 −9

= 0.33

Material

Poisson’s Coefficient

Aluminium = 0.30 Regarding the plastic behavior, the uniaxial tensile tests were performed on base materials for S420 and AA6005A T6 and the corresponding nonlinear plastic behaviors were characterized as shown in Figure 2. Steel

a) b) Figure 2. Plastic behavior obtained for a) AA6005A-T6 aluminum alloy and b) S420 steel alloy.

Concerning boundary conditions, the ECE R66 regulation suggests the following procedure to define the natural boundary condition, see Figure 3-a). A residual space is defined in the central section of the structure and a maximum displacement was recommended for this type of test, see Figure 3-b). Referring to Figure 3-a); α = 90 ° − arcsin ( 8 H 00 c ) (1) where is the cantrail height (in mm) of the vehicle measured from the horizontal plane on which it is standing as = 2784 ( ) . Therefore, = 73.3 ° and = 16.7 ° . A force with a magnitude of F is imposed with the following decomposition: = ( ) and = ( ) (2) It must be mentioned that the force magnitude must be defined as an approximated value, which would be higher than required; therefore, the suitable load must be defined by an incremental step.