PSI - Issue 42

Vítor M. G. Gomes et al. / Procedia Structural Integrity 42 (2022) 1552–1559 V.M.G. Gomes et al. / Structural Integrity Procedia 00 (2019) 000–000

1554

3

n

θ

π

b

q

q

a

α

α

φ

q

a

b

Fig. 1. Illustration of the determination of resolved shear stress direction (see Susmel (2010)).

3. Parabolic Leaf Springs in Freight Wagons

3.1. Geometry

The UIC parabolic leaf spring applied in axle-suspension wagons is constituted by five leaves. The first set of four leaves are designed as main leaf and the last leaf the auxiliary leaf. Additionally, the first leaf is the most important one and it is denominated as master leaf. The UIC parabolic leaf springs illustrated in figure 2 is a two-stage leaf spring because it provides two regimes of sti ff ness. This feature improves the movement of the wagon for low and high weight goods. Other elements used to assemble the leaves such as the spring band, linings, taper-key, and gid-headed key. The general dimensions of UIC parabolic leaf springs is presented in Table 1.

h

W

Fig. 2. Illustration of main geometric parameters to describe the parabolic leaf spring accordingly UIC517 (2007) standard.

Table 1. Nominal characteristics of parabolic leaf spring provided by UIC 517. Characteristics

Symbol

Unit

Value

Length of main spring leaf (between the centres of the rolled eyes)

L

mm mm mm

1175

Cross-section of the 1 st set of spring leaves Cross-section of the 2 nd set of spring leaves

2 2

W W

ls × h ls , i ls × h ls , i

120 × 21 120 × 36