Papers by Keyword: Hull Structure

Abstract: Fiberglass reinforced plastic fishing boats is a new type of energy saving and emission reduction boats, which is a significant revolution of fishing craft. However, the design of FRP fishing vessels in China continue to use the similar method employed by steel fishing vessels, which ignores the designability of fiberglass, leading to the light and high strength characteristic of glass fiber buried. the typical structure of FRP boats were analyzed, including the study on the influence of core material on the mechanical properties of cap type girder and the feasibility by using the equal sectional dimension in the Patran software of beam element to equivalent simulate the cap-type material, which simplified the whole ship building process of the finite element model and improved the computational efficiency in this pape.

Abstract: To get the typical ship structures’ longitudinal bend stress in hogging condition, standard method and finite element method, two kinds of longitudinal strength calculating methods are studied and compared in this paper, the section elements of typical ship structures are calculated, the cabin’s finite model are established by ABAQUS, the stress distribution moiré topography are obtained, and the two methods are compared, get the following conclusion: for the section which has a regular shape, such as bottom plate, strength deck, the calculation results from the two methods are consistent; for the section which has a complex shape, such as bilge board, the results of finite method is more accurate than standard method; in standard method, for the section which has a large vertical height, such as side plate, dividing it into some plate units can enhance the calculating accuracy.

Abstract: According to the norms “the fatigue strength assessment for hull structures in 2007” issued by China Classification Society, the combined computing platform established is composed of mature hydrodynamic software SESAM from Det NorskeVeritas(DNV)and MSC.PATRAN/NASTRAN, the fatigue strength assessment for hull structure of a steel fishing vessel is studied.

Abstract: In this paper, active vibration control performance of the smart hull structure with Macro-Fiber Composite (MFC) is evaluated. The governing equations of motion of the hull structure with MFC actuators are derived based on the classical Donnell-Mushtari shell theory. Subsequently, modal characteristics are investigated and compared with the results obtained from finite element analysis and experiment. The governing equations of vibration control system are then established and expressed in the state space form. Linear Quadratic Gaussian (LQG) control algorithm is designed in order to effectively and actively control the imposed vibration. The controller is experimentally realized and control performances are evaluated.

Abstract: In the present paper, the dynamic characteristics of smart hull structure are investigated for the feasibility of Macro Fiber Composite (MFC) actuator in active vibration control of smart hull structure. MFC is an advanced anisotropic piezoceramic actuator. Finite element technique was used to ensure application to practical geometry and boundary conditions of smart hull structure. Using finite element method, modal analysis and strain distribution were first conducted to investigate dynamic characteristics of smart hull structure. Based on numerical modal analysis, the locations of MFC actuators are determined to achieve maximum control authority. Then, the MFC actuators are attached to the hull structure and natural frequencies and damping coefficients are identified through experimental modal test.

Abstract: In this paper, dynamic characteristics of an end-capped hull structure with surface bonded piezoelectric actuators are studied. Finite element technique is used to ensure application to practical geometry and boundary conditions of smart hull structure. Modal analysis is conducted to investigate the dynamic characteristics of the hull structure. Piezoelectric self-sensing actuators are attached where the maximum control performance can be obtained. Active controller based on Linear Quadratic Gaussian (LQG) theory is designed to suppress vibration of smart hull structure. It is observed that closed loop damping can be improved with suitable weighting factors in the developed LQG controller.