Benchmarks for higher-order modes evaluation in the free vibration response of open thin-walled beams due to the cross-sectional deformations

2021 ◽  
Vol 166 ◽  
pp. 107965
Author(s):  
Xiangyang Xu ◽  
Erasmo Carrera ◽  
Riccardo Augello ◽  
Ehsan Daneshkhah ◽  
Hao Yang
Keyword(s):  
Free Vibration ◽  
Higher Order ◽  
Vibration Response ◽  
Cross Sectional ◽  
Higher Order Modes ◽  
Thin Walled ◽  
The Cross ◽  
Free Vibration Response

scholarly journals On the role of large cross-sectional deformations in the nonlinear analysis of composite thin-walled structures

2020 ◽  
Author(s):  
E. Carrera ◽  
A. Pagani ◽  
R. Augello
Keyword(s):  
Composite Structures ◽  
Laminated Composite ◽  
Nonlinear Effects ◽  
Higher Order ◽  
Cross Sectional ◽  
Thin Walled Structures ◽  
Static Responses ◽  
Geometrical Nonlinear ◽  
Thin Walled ◽  
The Cross

AbstractThe geometrical nonlinear effects caused by large displacements and rotations over the cross section of composite thin-walled structures are investigated in this work. The geometrical nonlinear equations are solved within the finite element method framework, adopting the Newton–Raphson scheme and an arc-length method. Inherently, to investigate cross-sectional nonlinear kinematics, low- to higher-order theories are employed by using the Carrera unified formulation, which provides a tool to generate refined theories of structures in a systematic manner. In particular, beams and shell-like laminated composite structures are analyzed using a layerwise approach, according to which each layer has its own independent kinematics. Different stacking sequences are analyzed, to highlight the influence of the cross-ply angle on the static responses. The results show that the geometrical nonlinear effects play a crucial role, mainly when higher-order theories are utilized.

scholarly journals Higher-Order Free Vibration Analysis of Porous Functionally Graded Plates

2021 ◽  
Vol 5 (11) ◽  
pp. 305
Author(s):  
Slimane Merdaci ◽  
Hadj Mostefa Adda ◽  
Belghoul Hakima ◽  
Rossana Dimitri ◽  
Francesco Tornabene
Keyword(s):  
Free Vibration ◽  
Plate Theory ◽  
Free Vibration Analysis ◽  
Higher Order ◽  
Functionally Graded ◽  
Vibration Response ◽  
Governing Equations ◽  
First Order ◽  
Fg Plates ◽  
Free Vibration Response

The present work analyzes the free vibration response of functionally graded (FG) plates made of Aluminum (Al) and Alumina (Al2O3) with different porosity distributions, as usually induced by a manufacturing process. The problem is tackled theoretically based on a higher-order shear deformation plate theory, while proposing a Navier-type approximation to solve the governing equations for simply-supported plates with different porosity distributions in the thickness direction. The reliability of the proposed theory is checked successfully by comparing the present results with predictions available from literature based on further first-order or higher-order theories. A large parametric study is performed systematically to evaluate the effect of different mechanical properties, such as the material indexes, porosity volume fractions, porosity distributions, and length-to-thickness ratios, on the free vibration response of FG plates, as useful for the design purposes of most engineered materials and composite applications.

A Study on Structural System Identification and Damage Detection for Free Vibration Response Using the Wavelet Transform

2015 ◽  
Vol 752-753 ◽  
pp. 1029-1034
Author(s):  
Asnizah Sahekhaini ◽  
Pauziah Muhamad ◽  
Masayuki Kohiyama ◽  
Aminuddin Abu ◽  
Lee Kee Quen ◽  
...  
Keyword(s):  
Free Vibration ◽  
Damage Detection ◽  
Vibration Response ◽  
Structural System ◽  
Modal Parameter ◽  
Modal Parameter Identification ◽  
Complex Morlet Wavelet ◽  
Structural System Identification ◽  
Free Vibration Response ◽  
Energy Components

This paper presents a wavelet-based method of identification modal parameter and damage detection in a free vibration response. An algorithm for modal parameter identification and damage detection is purposed and complex Morlet wavelet is chosen as an analysis wavelet function. This paper only focuses on identification of natural frequencies of the structural system. The method utilizes both undamaged and damage experiment data of free vibration response of the truss structure system. Wavelet scalogram is utilizes for damage detection. The change of energy components for undamaged and damage structure is investigated from the plot of wavelet scalogram which corresponded to the detection of damage.

Contribution of Lamb wave modes in the formation of higher order modes cluster (HOMC) guided waves

2021 ◽  
pp. 095440622110424
Author(s):  
Z Abbasi ◽  
F Honarvar
Keyword(s):  
Finite Element ◽  
Wave Packet ◽  
Lamb Wave ◽  
Guided Waves ◽  
Element Model ◽  
Higher Order ◽  
Guided Wave ◽  
Cross Sectional ◽  
Higher Order Modes ◽  
Wave Modes

In recent years, Higher Order Modes Cluster (HOMC) guided waves have been considered for ultrasonic testing of plates and pipes. HOMC guided waves consist of higher order Lamb wave modes that travel together as a single nondispersive wave packet. The objective of this paper is to investigate the effect of frequency-thickness value on the contribution of Lamb wave modes in an HOMC guided wave. This is an important issue that has not been thoroughly investigated before. The contribution of each Lamb wave mode in an HOMC guided wave is studied by using a two-dimensional finite element model. The level of contribution of various Lamb wave modes to the wave cluster is verified by using a 2D FFT analysis. The results show that by increasing the frequency-thickness value, the order of contributing modes in the HOMC wave packet increases. The number of modes that comprise a cluster also increases up to a specific frequency-thickness value and then it starts to decrease. Plotting of the cross-sectional displacement patterns along the HOMC guided wave paths confirms the shifting of dominant modes from lower to higher order modes with increase of frequency-thickness value. Experimental measurements conducted on a mild steel plate are used to verify the finite element simulations. The experimental results are found to be in good agreement with simulations and confirm the changes observed in the level of contribution of Lamb wave modes in a wave cluster by changing the frequency-thickness value.

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