This article discusses possibilities of application of widely applied and promoted abroad methods of active dampening of vibration and pressure oscillations (antinoise technology) in order to reduce vibration transfer via vibro-insulating couplings (compensators) of fluid pipelines. This is required in solution of issues of vibration insulation of equipment with regard to foundation and environment along pipelines with working mediums, for instance, in transporting of oil and gas, in energy and transport engineering. Reasonability of operation of active system in combination with means of passive dampening of these impacts is demonstrated. In terms of efficiency and minimum energy consumptions by active system it is reasonable to apply active dampening of vibration and oscillations downstream of the vibro-insulator (compensator) where their level is significantly lower than in the source. In the case of pipeline this implies dampening of vibration and oscillation downstream of compensator and damper, however, such works are nearly unavailable. This is attributed to significant coupling between vibration and pressure oscillation in compensator and pipeline itself, complicating solution of the problem. It is concluded that for efficient application of active dampening in pipeline compensators it is required to develop compensators with minimum coupling between vibration and oscillations.

An approximated crack growth direction and coalescence of the multiple cracks were obtained for an aluminum alloy plate by the finite element approach (FEA). Self-similar as well as non-self-similar crack growths were observed based on relative position of multiple cracks. The FE predictions of crack growth direction are validated with an experimental results and good agreement is established. Typical numerical results are presented to examine the effect of changing the crack tip distance (S), crack offset distance (H) on crack growth direction and coalescence of a finite aluminum alloy aluminum plate. Based on the analysis and experimental results, a new mathematical models for self-similar and non-self similar crack growth are introduc