An analysis of free vibration of orthogonally stiffened cylindrical shells with stiffeners treated as discrete elements

“…The subscripts C , R and S refer to the cylindrical shell, rings (frames) and stringers, respectively. u , v and w are the shell displacements in the axial, circumferential and radial directions, respectively, which are denoted by x , 6 and z , respectively. The subscripted terms with commas indicates partial differentiation with respect to the subscripted variables.…”

Section: Structural Modelingmentioning

confidence: 99%

<title>Vibroacoustic modeling of the control of aircraft cabin noise using piezoelectric actuators</title>

et al. 1998

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A vibroacoustic modeling methodology for the simulation of noise transmission into an aircraft cabin previously developed by the authors is extended to include the effect of segmented piezoelectric actuation. The structural model of the aircraft fuselage is based on a stiffened shell theory developed by Egle and Sewall. The strain and kinetic energies of the shell, stringers and frames, and the strain energy for the extensional motion of the floor beams are used in a Rayleigh-Ritz analysis to obtain the structural model. The forcing term due to the acoustic pressure disturbance of the propellers is determined by using virtual work considerations. The passive and active effects of the segmented piezoelectric actuators are incorporated in the model by including their energies in the variational approach. The development of the acoustic model of the cabin reduces to a twodimensional analysis due to the presence of parallel fore and aft bulkheads. The coupled vibroacoustic model, which includes terms that represent the inherent fluid-structure interaction, is developed from the structural and acoustic modal models. The control performance of the piezoelectric actuators is evaluated by considering the minimization of the sum of the squares of the interior sound field or structural response at a number of finite locations as the control objective. The acoustic and structural responses to one actuator and sensor arrangement are evaluated and discussed.

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“…To overcome that limitation, there are some models of the shear deformation theories are given such as the first-order shear deformation theory (FSDT) [29,30], the higher-order shear deformation theories [31][32][33], and the simple first-order shear deformation theory [34][35][36][37]. In terms of the stiffened shell structures, studies about stiffened cylindrical shell were presented in many publications [38][39][40][41]. Many scientists also reported some researches on free vibration of functionally graded cylindrical shell resting on and not resting on elastic foundation are reinforced by rings or orthogonal stiffeners in the recent years [42][43][44][45][46][47][48][49].…”

Section: Introductionmentioning

confidence: 99%

Analytical solution for free vibration of stiffened functionally graded cylindrical shell structure resting on elastic foundation

Nguyen

Hoang

2019

SN Appl. Sci.

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In this work, the analytical solution for free vibration of functionally graded cylindrical shell with stiffeners resting on Winkler-Pasternak foundation with several boundary conditions is reported. Material properties of the cylindrical shell are assumed to be varying smoothly and continuously across the thickness according to the power law distribution of the volume fraction of constituents. The governing equations of the stiffened functionally graded cylindrical shell resting on elastic foundation are obtained by using Hamilton's principle, the first-order shear deformation theory and the Lekhnitsky smeared stiffeners technique. The purpose of the present study is to illustrate a simple approach to get the natural frequency of the stiffened functionally graded cylindrical shell with several boundary conditions by using the Galerkin method with beam functions of the axial displacement fields. A good agreement is obtained as the present results in comparison with those of publications in the existing literature. In numerical investigations, some influences of volume fraction index, cylindrical shell's geometric ratios, boundary conditions and elastic foundation parameters on the fundamental frequency of the stiffened cylindrical shell resting on elastic foundation are given.

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An analysis of free vibration of orthogonally stiffened cylindrical shells with stiffeners treated as discrete elements

Cited by 7 publications

References 2 publications

Free vibration analysis of a circular cylindrical shell using the Rayleigh–Ritz method and comparison of different shell theories

Free vibration analysis of a circular cylindrical shell using the Rayleigh–Ritz method and comparison of different shell theories

<title>Vibroacoustic modeling of the control of aircraft cabin noise using piezoelectric actuators</title>

Analytical solution for free vibration of stiffened functionally graded cylindrical shell structure resting on elastic foundation

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