Scattering and Transmission of Mixed-Mode Waves in Delaminated Thick Composite Beams

2001 ◽  
Author(s):  
D. Roy Mahapatra ◽  
S. Gopalakrishnan ◽  
T. S. Sankar
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Wave Equations ◽  
Laminated Composite ◽  
Element Model ◽  
Composite Beams ◽  
Unidirectional Composite ◽  
Element Discretization ◽  
Spectral Finite Element ◽  
Element Method

Abstract A spectral finite element model is developed to study scattering and transmission of axial-flexural-torsional coupled waves in multi-sitedelaminated thick composite beams. The analysis may find its suitability and superiority to capture the high frequency dynamics of laminated composite structure in vibrating environment and for health monitoring in combination with non-destructive test data. Spectral finite element considering first order shear deformation is used to model the delaminated segments along the span of the beam, as well as the delaminated ply-groups in thickness direction. This spectral element is derived from exact solution to the 3D governing wave equations in Fourier domain. As aresult, the thin sublaminates and beam segments do not lock. Spatial discretization is carried out in a similar way as in conventional finite element method. The major differences from conventional finite element method are (1) the transformation of all the fields from temporal to frequency domain is carried out using Fast Fourier Transform (FFT) algorithm, (2) the global system is solved at each frequency step (3) fine meshing at the delamination tip to capture the crack-tip singularity (as in conventional finite element discretization) is not required (4) the overall system size becomes many order smaller than that in conventional finite element methods. The study essentially includes unsymmetry induced due to ply orientations and due to multiple delamination across beam thickness. A case study is presented to show the effect of wave transmission and scattering by a single through delamination in unidirectional composite beam.

scholarly journals Nonlinear Vibrations of 3D Laminated Composite Beams

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
S. Stoykov ◽  
S. Margenov
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Geometrical Nonlinearity ◽  
Strain Tensor ◽  
Laminated Composite ◽  
Composite Beams ◽  
Orthotropic Materials ◽  
Warping Function ◽  
Laminated Composite Beams ◽  
Element Method

A model for 3D laminated composite beams, that is, beams that can vibrate in space and experience longitudinal and torsional deformations, is derived. The model is based on Timoshenko’s theory for bending and assumes that, under torsion, the cross section rotates as a rigid body but can deform longitudinally due to warping. The warping function, which is essential for correct torsional deformations, is computed preliminarily by the finite element method. Geometrical nonlinearity is taken into account by considering Green’s strain tensor. The equation of motion is derived by the principle of virtual work and discretized by thep-version finite element method. The laminates are assumed to be of orthotropic materials. The influence of the angle of orientation of the laminates on the natural frequencies and on the nonlinear modes of vibration is presented. It is shown that, due to asymmetric laminates, there exist bending-longitudinal and bending-torsional coupling in linear analysis. Dynamic responses in time domain are presented and couplings between transverse displacements and torsion are investigated.

scholarly journals Forced Vibration Analysis of Laminated Composite Shells Reinforced with Graphene Nanoplatelets Using Finite Element Method

2020 ◽  
Vol 2020 ◽  
pp. 1-17 ◽  
Author(s):  
Trung Thanh Tran ◽  
Van Ke Tran ◽  
Pham Binh Le ◽  
Van Minh Phung ◽  
Van Thom Do ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Forced Vibration ◽  
Vibration Analysis ◽  
Shear Deformation Theory ◽  
Laminated Composite ◽  
Thermal Environments ◽  
Forced Vibration Analysis ◽  
Laminated Composite Shells ◽  
Element Method

This paper carries out forced vibration analysis of graphene nanoplatelet-reinforced composite laminated shells in thermal environments by employing the finite element method (FEM). Material properties including elastic modulus, specific gravity, and Poisson’s ratio are determined according to the Halpin–Tsai model. The first-order shear deformation theory (FSDT), which is based on the 8-node isoparametric element to establish the oscillation equation of shell structure, is employed in this work. We then code the computing program in the MATLAB application and examine the verification of convergence rate and reliability of the program by comparing the data of present work with those of other exact solutions. The effects of both geometric parameters and mechanical properties of materials on the forced vibration of the structure are investigated.

scholarly journals Finite Element Method modeling of Additive Manufactured Compressor Wheel

2021 ◽  
Author(s):  
Márton Tamás Birosz ◽  
Mátyás Andó ◽  
Sudhanraj Jeganmohan
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Finite Element Method Simulation ◽  
Element Model ◽  
Tensile Tests ◽  
Raw Material ◽  
Isotropic Hardening ◽  
Compressor Wheel ◽  
Material Extrusion ◽  
Element Method

AbstractDesigning components is a complex task, which depends on the component function, the raw material, and the production technology. In the case of rotating parts with higher RPM, the creep and orientation are essential material properties. The PLA components made with the material extrusion process are more resistant than VeroWhite (material jetting) and behave similarly to weakly cross-linked elastomers. Also, based on the tensile tests, Young’s modulus shows minimal anisotropy. Multilinear isotropic hardening and modified time hardening models are used to create the finite element model. Based on the measurements, the finite element method simulation was identified. The deformation in the compressor wheel during rotation became definable. It was concluded that the strain of the compressor wheel manufactured with material extrusion technology is not significant.

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