Non-axisymmetric dynamic response of buried orthotropic cylindrical shellsunder moving load

The dynamic response of buried pipelines has gained considerable importance because these pipelines perform vital role in conducting energy, water, co mmunication and transportation. After realizing the magnitude of damage, an d hence, the human uncomfort and the economical losses, researchers have pa id sincere attention to this problem. A number of papers have appeared in t he past which discuss the different aspects of the problem. This paper pres ents a theoretical analysis of nonaxisymmetric dynamic response of buried o rthotropic cylindrical shell subjected to a moving load along the axis of t he shell. The orthotropic shell has been buried in a homogeneous, isotropic and elastic medium of infinite extent. A thick shell theory including the effects of rotary inertia and shear deformation has been used. A perfect bo nd between the shell and the surrounding medium has been assumed. Results h ave been obtained for very hard (rocky), medium hard and soft soil surround ing the shell. The effects of shell orthotropy have been brought out by var ying the non-dimensional orthotropic parameters over a long range. Under th ese conditions the shell response is studied in axisymmetric mode as well a s in the flexural mode. It is observed that the shell response is significa ntly affected by change in orthotropic parameters and also due to change of response mode. It is observed that axial deformation is large in axisymmet ric mode as compared to that in flexural mode.