Effect of stiffness of the damping layer on the reaction of a cylindrical shell to an axisymmetric moving load

1977 ◽  
Vol 13 (9) ◽  
pp. 878-883
Author(s):  
V. I. Pozhuev
2013 ◽  
Vol 441 ◽  
pp. 461-464
Author(s):  
Jiu Dan Zhang ◽  
Bin Zhen ◽  
Xiang Li

The critical velocity for an infinite cylindrical shell subjected a moving load with a constant velocity is analyzed in this paper. It is found that the critical velocity problem can be translated into a distribution of the real roots of a quadruplicate equation, which can be solved by using Descartes sign method and complete discrimination system for polynomials. Our research shows that the number of the critical velocities for an infinite cylindrical shell always is even number. Furthermore the longitudinal wave velocity is not one critical velocity for the shell. Our results are different from the conclusion drawn by other authors that there are three critical velocities in an infinite shell, and the longitudinal wave velocity is the maximum critical velocity. Then further studies are needed to clarify these questions.


TEM Journal ◽  
2021 ◽  
pp. 815-819
Author(s):  
Boris A. Antufev ◽  
Vasiliy N. Dobryanskiy ◽  
Olga V. Egorova ◽  
Eduard I. Starovoitov

The problem of axisymmetric hydroelastic deformation of a thin cylindrical shell containing a liquid under the action of a moving load is approximately solved. It is reduced to the equation of bending of the shell and the condition of incompressibility of the liquid in the cylinder. The deflections of the shell and the level of lowering of the liquid are unknown. For solution, the Galerkin method is used and the problem is reduced to a system of nonlinear algebraic equations. A simpler solution is considered without taking into account the incompressibility condition. Here, in addition to the deformed state of the shell, the critical speeds of the moving load are determined analytically.


Author(s):  
Alain Berry ◽  
Rémy Oddo ◽  
Raymond Panneton ◽  
Jean Nicolas

Abstract A pressure pulp screen is a machine used in the pulp and paper industry to remove and class cellulose fibres in paper pulp. It involves an inner perforated cylindrical basket which receives the pulp under pressure, an inner rotor with profiled blades used to clear the holes or slits of the basket, and an outer cylindrical shell. The noise radiated by the outer shell is characterized by discrete frequencies in mid- and high frequency (1–4 kHz). A preliminary study has shown that the radiated noise is due to the vibration of the perforated basket under the moving load of the rotor. This vibration is transmitted to the outer shell through various paths which were analyzed and classified. An analytical model of the vibroacoustic behavior of a cylindrical shell under a circumferentially moving load was used to establish various rotating speed regimes with respect to the vibration and sound radiation of the shell. It was shown that a circumferential modulation of the load (corresponding to the effect of holes or slits on the inner basket) leads to theoretical noise spectra similar to measured data. On the practical front, the model was used to identify significant design parameters with respect to the noise of the machine. The paths of energy transmission from the basket to the outer shell were studied and various noise reduction approaches have been investigated.


Author(s):  
Farhad Davaripour ◽  
Bruce W. T. Quinton

In accidental scenarios on subsea pipeline systems, like the collision of two adjacent subsea risers, accidental loads are commonly considered as stationary loads; stationary loads refer to loads that act only normal to the pipe at one location. Hence, the potential considerable effects of moving (sliding) accidental loads are neglected; the term moving load refers to the location with respect to time. Accordingly, recent works for ship hull structures show that the structural resistance mobilized against the moving loads is significantly lower than against the stationary loads of similar magnitude; when the loads incite plastic damage. As such, it is reasonable to study the effects of lateral motion of accidental loads on the response of subsea pipelines. This paper implements finite element analyses to investigate the load carrying capacity of a cylindrical shell subject to moving loads; LS-Dyna software package with explicit time-integration scheme is employed in numerical simulations; only crumpling deformation of the cylinders are studied. This research demonstrates that the capacity of a cylindrical shell subject to a moving load, causing plastic damage, is considerably less than its capacity under a stationary load of similar magnitude.


Sign in / Sign up

Export Citation Format

Share Document