TY - CONF
TI - Vibration of Flexible Member in Offshore Structures
AU - Sravani, Madagala
AU - Vijayan, Kiran
A2 - Saha, Sandip Kumar
A2 - Mukherjee, Mousumi
T3 - Lecture Notes in Civil Engineering
AB - There are many flexible vertical members in offshore platforms like mooring lines and risers. These are exposed to wave, vessel motion and drilling loads during operation. For the smooth operation of these structures, the lateral excursion of these members should be minimal. This paper explains about the vibration analysis of a flexible vertical member subjected to base excitation. Initially, the flexible member was analysed as a SDOF non-linear spring-mass system. A qualitative understanding of the system was determined by solving the system using continuation method. Further, a numerical and experimental analysis was carried out on this member. Numerically, the member was analysed as an Eulerâ€“Bernoulli beam in MATLAB using the finite element method with three degrees of freedom at each node. The buckling load was determined using the Eigen value analysis. The minimum length required for buckling under gravity load was determined. The system was subjected to base excitation and the variation in the maximum response with respect to base excitation frequency was noted in the axial and lateral direction. The maximum response was obtained near the resonant frequency. Experimentally, the flexible member with a force transducer at its base was connected to the modal exciter through a stinger. The material of the member chosen was acrylic polymer as it buckles easily and can be used for testing. Forced excitation was provided using the modal exciter. On varying the frequency, the response of the member was observed. The length of the member was also a parameter that was varied such that the excursion was within controllable limits. Also, the area of the cross section in the upper half of the section was increased as an additional parameter for controlling the excursion. It was observed that the excursion was reduced as obtained from the theoretical analysis.
C1 - Singapore
C3 - Recent Advances in Computational Mechanics and Simulations
DA - 2020/11/24/
PY - 2020
DO - 10.1007/978-981-15-8138-0_7
DP - Springer Link
SP - 85
EP - 93
LA - en
PB - Springer
SN - 9789811581380
KW - Buckling analysis
KW - Continuation method
KW - Non-linear dynamics
ER -