Optimization of a Two Joint Cross-Ply Laminated Conical Shells to Minimize The Natural Frequencies

2015 ◽  
Keyword(s):  
Natural Frequencies ◽  
Conical Shells ◽  
Laminated Conical Shells

scholarly journals The influence of the manufacturing constraints on the optimal design of laminated conical shells

2020 ◽  
Vol 235 ◽  
pp. 111820 ◽  
Author(s):  
Adam Stawiarski ◽  
Małgorzata Chwał ◽  
Marek Barski ◽  
Aleksander Muc
Keyword(s):  
Optimal Design ◽  
Manufacturing Constraints ◽  
Conical Shells ◽  
Laminated Conical Shells

scholarly journals Effect of Location of Delamination on Free Vibration of Cross-Ply Conical Shells

2012 ◽  
Vol 19 (4) ◽  
pp. 679-692 ◽  
Author(s):  
Sudip Dey ◽  
Amit Karmakar
Keyword(s):  
Finite Element ◽  
Free Vibration ◽  
Natural Frequencies ◽  
Dynamic Equilibrium ◽  
Twist Angle ◽  
Structural Instability ◽  
Numerical Results ◽  
Mode Shapes ◽  
Iteration Algorithm ◽  
Conical Shells

Location of delamination is a triggering parameter for structural instability of laminated composites. In this paper, a finite element method is employed to determine the effects of location of delamination on free vibration characteristics of graphite-epoxy cross-ply composite pre-twisted shallow conical shells. The generalized dynamic equilibrium equation is derived from Lagrange's equation of motion neglecting Coriolis effect for moderate rotational speeds. The formulation is exercised by using an eight noded isoparametric plate bending element based on Mindlin's theory. Multi-point constraint algorithm is utilized to ensure the compatibility of deformation and equilibrium of resultant forces and moments at the delamination crack front. The standard eigen value problem is solved by applying the QR iteration algorithm. Finite element codes are developed to obtain the numerical results concerning the effects of location of delamination, twist angle and rotational speed on the natural frequencies of cross-ply composite shallow conical shells. The mode shapes are also depicted for a typical laminate configuration. Numerical results obtained from parametric studies of both symmetric and anti-symmetric cross-ply laminates are the first known non-dimensional natural frequencies for the type of analyses carried out here.

Natural frequencies of meridional vibration in thin conical shells

AIAA Journal ◽  
1964 ◽  
Vol 2 (10) ◽  
pp. 1825-1827 ◽  
Author(s):  
R. E. KEEFEE
Keyword(s):  
Natural Frequencies ◽  
Conical Shells

Free Vibration of Axially Loaded Laminated Conical Shells

1999 ◽  
Vol 66 (3) ◽  
pp. 758-763 ◽  
Author(s):  
L. Tong
Keyword(s):  
Free Vibration ◽  
Axial Load ◽  
Governing Equations ◽  
Load Effect ◽  
Critical Buckling Load ◽  
Conical Shells ◽  
Axial Tension ◽  
Axially Loaded ◽  
Constant Axial Load ◽  
Laminated Conical Shells

Analytical solutions for the three displacements are obtained, in the form of power series, directly from the three governing equations for free vibration of laminated conical shells under axial load. Numerical results are presented for free vibration of axially loaded laminated conical shells with different geometric parameters and under two types of boundary conditions. It is found that an axial tension increases the frequencies while an axial compression decreases the frequencies. For the shells studied, the effect of axial load on the lowest frequency of the shell is found to be not sensitive to change in semivertex angle when the applied axial load is kept as a constant fraction of the critical buckling load. However, the axial load effect becomes very sensitive to variation in semivertex angle when a constant axial load is applied.

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