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In this paper the earlier elaborated finite-element method of calculating the stress intensity factor for stationary cracks at dynamic loading by means of cohesion finite elements and on the basis of the method of lines is generalized for high-velocity cracks. The method in question does not require rearranging the finite-element mesh. The crack growth is modeled by consecutively releasing the nodes located on the crack line. The calculated data are compared with the analytical solutions of other researchers and with the experimental data.

With the purpose of improving the durability of the industrial cracking catalyst Lyuks, the influence of ultrasonic treatment (UST) on the dispersion, durability, hydrophilia, and phase structure of components of the cracking catalyst and catalytic compositions as a whole were studied for the first time. The composition of an industrially manufactured cracking catalyst consists of montmorillonite, the product of hydrargillite thermoactivation, amorphous silica-alumina, and zeolite Y. Applying the ultrasonic treatment to suspensions of individual components of the catalytic composition results in growing their dispersion, at which point is discovered an increase of hydrophilia of montmorillonite particles, an alteration of velocities of aluminium hydroxide phase changes, and an improvement of the durability of calcinated montmorillonite extrudates from 200 to 300 kg/cm2. The ultrasonic treatment of the suspension of the cracking catalyst composition also leads to growing its dispersion, thereby improving the durability from 80 to 125 kg/cm2 and bulk density of the ready cracking catalyst on retention of the high catalytic activity without modifying its structure and incorporation of an additional peptization stage used traditionally for this purpose.