scholarly journals The Ultimate Strength of Ring Stiffened Cylindrical Shell and Its Influence Factors

Author(s):  
XIONG Zhixin1 ◽  
◽  
HUI Hanju1 ◽  
HUANG Zhiquan2 ◽  
◽  
...  
Author(s):  
Sarmila Sahoo

The free vibration of laminated composite stiffened cylindrical shell panels in the presence of cutout is investigated. A finite element code is developed using eight-noded curved quadratic isoparametric element for shell with a three noded beam element for stiffener and the formulation is validated through solution of benchmark problems which were earlier solved by other researchers. Parametric study is carried out varying the size of the cutouts and their positions with respect to the shell centre for different edge constraints. The results are presented in the form of figures and tables. The results are further analyzed to suggest guidelines to select optimum size and position of the cutout with respect to shell centre considering the different practical constraints.


Author(s):  
Lin Wang ◽  
Feng Li

The influence of middle frames on the ultimate strength of pressure cylindrical shell is studied in this paper, the relationship between the critical stiffness of middle frames and the value of α is discussed, and the criterion of the necessity of adding middle frames on the issue of elastoplastic stabilities is specified.


Author(s):  
C-J Liao ◽  
W-K Jiang ◽  
H Duan ◽  
Y Wang

An analytical study on the vibration and acoustic radiation from an axially stiffened cylindrical shell in water is presented. Supposing that the axial stiffeners interact with the cylindrical shell only through radial forces, the reaction forces on the shell from stiffeners can be expressed by additional impedance. The coupled vibration equation of the finite cylindrical shell with axial stiffening is derived; in this equation additional impedance caused by the axial stiffeners is added. As a result, the vibration and sound radiation of the shell are dependent on the mechanical impedance of the shell, the radiation sound impedance, and the additional impedance of the axial stiffeners. Based on the numerical simulation, it is found that the existence of axial stiffeners decreases the sound radiation and surface average velocity, whereas it increases the radiation factor. The characteristics of the acoustic radiation can be understood from the simulation with good results, which show that the presented methodology can be used to study the mechanism of the acoustic radiation of the complicated cylindrical shell and to optimize its design.


2013 ◽  
Vol 20 (3) ◽  
pp. 459-479 ◽  
Author(s):  
Meixia Chen ◽  
Jianhui Wei ◽  
Kun Xie ◽  
Naiqi Deng ◽  
Guoxiang Hou

Wave based method which can be recognized as a semi-analytical and semi-numerical method is presented to analyze the free vibration characteristics of ring stiffened cylindrical shell with intermediate large frame ribs for arbitrary boundary conditions. According to the structure type and the positions of discontinuities, the model is divided into different substructures whose vibration field is expanded by wave functions which are exactly analytical solutions to the governing equations of the motions of corresponding structure type. Boundary conditions and continuity equations between different substructures are used to form the final matrix to be solved. Natural frequencies and vibration mode shapes are calculated by wave based method and the results show good agreement with finite element method for clamped-clamped, shear diaphragm – shear diaphragm and free-free boundary conditions. Free vibration characteristics of ring stiffened cylindrical shells with intermediate large frame ribs are compared with those with bulkheads and those with all ordinary ribs. Effects of the size, the number and the distribution of intermediate large frame rib are investigated. The frame rib which is large enough is playing a role as bulkhead, which can be considered imposing simply supported and clamped constraints at one end of the cabin and dividing the cylindrical shell into several cabins vibrating separately at their own natural frequencies.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Anbin Yu ◽  
Yinglong Zhao ◽  
Youqian Wang ◽  
Ben Zhang

Based on the Flügge theory and orthotropic theory, the acoustic vibration coupling model of ring-stiffened cylindrical shell is established by using the wave propagation method and virtual source method. And the effects of water immersion on both sides, free surface, and hydrostatic pressure on the cylindrical shell are considered in the coupling model. Muller three-point iterative method is used to solve the coupling frequency. The calculation results of degradation theory are compared with COMSOL’s calculation results and experimental results, respectively, which verifies the reliability of the theoretical method. Finally, the influence of fluid load, ring rib parameters, boundary conditions, hydrostatic pressure, and free surface on the coupled vibration of ring-stiffened cylindrical shell is analyzed by an example.


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