Effect of non-stationary external forces on vibrations of composite pipelines conveying fluidA.A. Verlan, B.A. Khudayarov, F.Zh. Turaev, N.N. Yuldashev and K. RuzmetovE3S Web of Conf., 365 (2023) 05014DOI: https://doi.org/10.1051/e3sconf/202336505014