چكيده به لاتين
The development and high speed of railway lines has led to an increase in the speed of trains. The stability and comfort of movement and the comfort of cargo and passengers have prompted researchers to turn to new systems in the train. Magnetic dampers that create viscous and damping properties with iron particles have recently been used in industries as shock absorbers or energy and vibration absorbers. The application of magnetic dampers in the suspension system as a semi-active system brought about improvements in the field of train suspension system, which led to the improvement of the performance of the train suspension system compared to the previous systems. However, the use of magnetic dampers in the connections between two wagons has received less attention from researchers, especially in freight wagons. In any case, the feasibility of using these shock absorbers in wagon joints requires checking the conditions of design, operation, maintenance and repair, and most importantly, the cost of their implementation. Smart materials are materials that can sense external stimuli and are able to adapt to changing external conditions. Smart materials are a physical structure that has a purpose, means and necessity to achieve that purpose and a biological pattern of performance. Magnetically and electrically responsive materials. . Magnetic fluid consists of a liquid carrier, iron particles with a diameter of several microns, and surfactant additives, which are used to prevent particles from settling. The magnetic field changes the shear strain rate of the magnetic fluid, in the same sense that the fluid becomes more sensitive to shear with the increase of the magnetic field. When a magnetic field is applied, the magnetic fluid changes from a liquid state to a semi-solid state in just a few milliseconds. Therefore, it is an infinitely variable and controllable magnetic damper capable of applying large damping forces. Magnetic dampers offer a significant solution for energy absorption in mechanical systems, which can be considered as a fail-safe device. In this thesis, magnetic dampers are used as dampers used in a train hook shock absorber. Silicone oil and MRF 336AG oil were used to make the shock absorber with magnetic damper, CK60 steel was used to make the shock absorber spring, and VCN steel was used for the shock absorber shell steel. After designing and preparing the plans and making the shock absorber, a dynamic test was performed on the magnetic damper in four compressive forces of 6, 8, 10, and 12 tons and in four current intensities of 0, 0.5, 1, and 1.5. The results showed that when using magnetic oil in the shock absorber after applying the current intensity, the force damped by the damper increases by 21, 42 and 51% for currents of 0.5, 0 and 1.5 amps, respectively. While these values are 32, 42 and 48% for the state without using magnetic oil. In general, the force damped by the magnetic damper is 50% more than the damper without magnetic oil.
