International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

Abstract. The structure and some properties of magnetostrictive powder materials of the Fe .Ga and .Fe-(Ga+Al) systems, obtained by sintering at a temperature of 1150 oC in a neutral Ar environment for 1 h, were studied. The structure and phase composition of the obtained materials were studied. Mechanical tests of the samples were carried out, corrosion resistance was determined and magnetostrictive properties of samples of the composition Fe-Ga and Fe-1.7Al-19.3Ga were evaluated as the most promising for use as magnetostrictive materials. An increase in hardness and level of compressive strength of the material of the composition Fe-1.7Al-19.3Ga compared to materials of the composition Fe-21.4Ga was revealed. In terms of corrosion resistance, these materials are corrosion-resistant materials (3-4 points on a 10-point scale of corrosion resistance). The highest level of magnetostriction is possessed by materials of the dual composition Fe 21.5 wt.%Ga (>210 ppm). The material with the composition Fe 19.3 wt. % Ga-1.75 wt. % Al, which had a lower level of compressive elasticity, also differed in a lower value of magnetostriction (130 ppm). The level of magnetostriction of the studied materials is within the requirements for commercial deformed Fe-Ga alloys (galfenols).

In this paper is presented the optimal design of quarter car vehicle suspensions. During the optimisation the three design criteria which have been used are; vertical vehicle body acceleration, dynamic tire load and suspension working space. For implementing a optimization a comparison of two optimisation algorithms: Sequential Quadratic Program (SQP) and Genetic Algorithms (GAs). will be chosen five design parameters: sprung and un-sprung mass, spring stiffness, damping coefficient and tire stiffness. Through the simulation in Matlab it will be shown that GA is more powerful tool to find the global optimal point, without any restrictive requirements on the gradient and Hessian Matrix, while SQP has local convergence properties. The main focus of this research will be on minimising the vertical vehicle body acceleration subjected to a suspension working space and the dynamic tire load. At the end of this paper, it will be shown the comparison between the simulation carried out with nominal and optimal values of design parameters.