Nonlinear dynamic analysis of cantilevered pipe conveying fluid with local rigid segment

An effort is made in this paper to deal with the dynamical problem of straight and curved fluid-conveying pipes consisting of both flexible and rigid pipe segments. To obtain the universal nonlinear governing equations of the considered pipe system, the 2-node planar curved elements based on the absolute nodal coordinate formulation (ANCF) are utilized to discretize the pipe, and the extended Lagrange equations written for systems containing non-material volumes are employed. With the help of the obtained governing equations, the nonlinear static analysis (only for the curved pipe), linear stability analysis, and nonlinear dynamic analysis are conducted, mainly devoting to exploring the impacts of the presence, location and length of the rigid segment on the static and dynamic characteristics of the considered cantilevered pipe system. Numerical results show that the effects of a rigid segment on the dynamical behaviors of straight and curved pipes have both similarities and differences. The presence of a rigid segment can affect the oscillating shapes of both straight and curved pipes. Both period-1 and period-2 motions can be generated in curved pipes due to the presence of the rigid segment, while only period-1 rather than period-2 motions could be detected in the dynamical system of straight pipes. In addition, the presence, location and length of the rigid segment are found to have great impacts on the static equilibrium configurations of the curved pipe system under consideration.

Automated summary

This paper investigates the dynamical problem of fluid-conveying pipes consisting of both flexible and rigid pipe segments. The nonlinear governing equations of the pipe system are obtained using the absolute nodal coordinate formulation (ANCF) and extended Lagrange equations. Various analyses are conducted to explore the effects of the rigid segment on the static and dynamic characteristics of the pipe system. The results show that the presence, location, and length of the rigid segment significantly influence the oscillating shapes and static equilibrium configurations of both straight and curved pipes.