PSI - Issue 59

634 O. Fomin et al. / Procedia Structural Integrity 59 (2024) 629–635 6 Oleksij Fomin, Serhii Kara, Dmytro Turovets, Andrii Klymash, Serhii Kuzmenko / Structural Integrity Procedia 00 (2023) 000 – 000

cars, even considering their high cost. The efficiency of the use of rolling stock directly depends on the material capacity of the structure, its durability, the cost of production, and operating costs. At the same time, the main parameters of freight cars (tare weight, load capacity, durability, etc.), which are made of traditional materials, have practically no reserve for further improvement. The use of composite materials in the elements of the freight car helps to increase corrosion resistance without the use of an expensive coating, which allows for a reduction in the frequency of repairs or to avoid them. In addition, the use of new materials ensures a reduction in the weight of the wagon. The cost of a typical fibrous polymer composition is, on average, 3 times higher than the cost of a steel sheet, but at the same time, the effectiveness of the use of the composite material is higher due to its strength characteristics. In the production of parts with increased requirements for mechanical properties, savings are achieved by reducing the thickness and weight of the part compared to a metal product. During the production of parts of a complex shape, the costs of processing and painting can be significantly lower compared to the production of similar components from steel sheets. The most famous and widespread representatives of composite materials used in engineering, including railway transport, are fibrous polymer composite materials (carbon, glass, organoplastics). Prerequisites have also now appeared for using polymer composite materials based on carbon nanotubes in the design of transport for various purposes. Carbon nanotubes have high strength and elasticity and can withstand high stress without breaking. Table 4 shows various polymer fibers and their mechanical properties

Table 4. Mechanical properties of different fibers.

Average strength on base 10 mm, σf

Modulus elasticity, E

Density, ρ·10 -2, kg/m 3

Boundary formation ε f , %

Brand

GPa

Fiberglass

VM-1

2.58 2.56 2.89 2.49 1.45 1.45

95 74

4.20 2.00 3.50 4.80

4.8 3.6 3.2 5.4

Acid resistant No. 7 – A

M-glass S – 994 Turlon Kevlar

110

87

Organic aramid fibers

130÷160

3.3÷3.6

2.7÷3.5

60

2.7

4.5

Carbon fibers

Coulomb

1.9 1.6

2.0 2.0

0.4 1.3 1.3 0.5

400÷600

Elur

150 238

Thornel-300 Modmor-1

1.77 2.0

3.15

400÷500

1.7÷2.5

4. Conclusions Based on the results of impact tests of the device for transporting semi-trailers on a platform wagon with a semi trailer installed on it in a loaded state, it is established that the maximum stresses do not exceed the value (during impact tests from the side of the device for transporting semi-trailers, the maximum value of stresses was 225.97 MPa, channel 8; 277.42 MPa, channel 1; during impact tests from the opposite side of the device for transporting semi- trailers, the maximum value of stresses was 169.03 MPa, channel 8), σ y =345 MPa. During the wedge drop tests, the maximum stress value was 35.22 MPa, channel 11 during lateral sway. This study provides an opportunity to further improve devices for transporting semi-trailers on a platform wagon. For example, selecting materials (aluminum, composite, etc.), can increase strength and shock resistance during non-linear loads from an installed semi-trailer.