scholarly journals Free Vibration Analysis Of Layered Beams With Delamination Damage-An ANSYS®-Based FEM Investigation

2021 ◽  
Author(s):  
Anahita R. Ghorbanzad
Keyword(s):  
Damage Identification ◽  
Focal Point ◽  
Vibrational Analysis ◽  
Free Vibration Analysis ◽  
Layered Beams ◽  
Cantilevered Beam ◽  
1D Model ◽  
Size Type ◽  
Free Mode ◽  
Fixed Beam

Identifying delamination has been a focal point for many researchers. The reason for this interest arises from criticality of delamination in a variety of industries: automotive, aerospace, and construction. Therefore, vibration-based damage identification method is applied to detect, locate and characterize the damage in a mechanical structure. In this method, natural frequency as a diagnostic tool to determine the integrity of a structure has been utilized. The current research presents a FEM-based investigation into free vibrational analysis of defective layered beams with free mode delamination. It is shown that the size, type and location of delamination directly influence system non-dimensional frequencies. Based on an existing 1D model, the investigation is extended to 2D modelling for single-and-double-delamination cases. In each case, Fixed-Fixed and cantilevered beam configurations, both centred and off-centred delamination conditions are studied. Further, a 3D model is also developed for single delamination of a Fixed-Fixed beam. All simulation results show excellent agreement with the data available in the literature. The ANSYS ® FEM-based modelling approach presented here is general and accurately predicts delamination effects on the frequency response of beam structures.

scholarly journals Free Vibration Analysis Of Layered Beams With Delamination Damage-An ANSYS®-Based FEM Investigation

2021 ◽  
Author(s):  
Anahita R. Ghorbanzad
Keyword(s):  
Damage Identification ◽  
Focal Point ◽  
Vibrational Analysis ◽  
Free Vibration Analysis ◽  
Layered Beams ◽  
Cantilevered Beam ◽  
1D Model ◽  
Size Type ◽  
Free Mode ◽  
Fixed Beam

Identifying delamination has been a focal point for many researchers. The reason for this interest arises from criticality of delamination in a variety of industries: automotive, aerospace, and construction. Therefore, vibration-based damage identification method is applied to detect, locate and characterize the damage in a mechanical structure. In this method, natural frequency as a diagnostic tool to determine the integrity of a structure has been utilized. The current research presents a FEM-based investigation into free vibrational analysis of defective layered beams with free mode delamination. It is shown that the size, type and location of delamination directly influence system non-dimensional frequencies. Based on an existing 1D model, the investigation is extended to 2D modelling for single-and-double-delamination cases. In each case, Fixed-Fixed and cantilevered beam configurations, both centred and off-centred delamination conditions are studied. Further, a 3D model is also developed for single delamination of a Fixed-Fixed beam. All simulation results show excellent agreement with the data available in the literature. The ANSYS ® FEM-based modelling approach presented here is general and accurately predicts delamination effects on the frequency response of beam structures.

scholarly journals On the Finite Element Free Vibration Analysis of Delaminated Layered Beams: A New Assembly Technique

2021 ◽  
Author(s):  
Nicholas H. Erdelyi ◽  
Seyed M. Hashemi
Keyword(s):  
Finite Element ◽  
Natural Frequencies ◽  
Free Vibration Analysis ◽  
Beam Theory ◽  
Bending Vibration ◽  
Natural Frequencies And Modes ◽  
Layered Beams ◽  
Assembly Technique ◽  
Free Mode ◽  
Element Free

The dynamic analysis of flexible delaminated layered beams is revisited. Exploiting Boolean vectors, a novel assembly scheme is developed which can be used to enforce the continuity requirements at the edges of delamination region, leading to a delamination stiffness term. The proposed assembly technique can be used to form various beam configurations with through width delaminations, irrespective of the formulation used to model each beam segment. The proposed assembly system and the Galerkin Finite Element Method (FEM) formulation are subsequently used to investigate the natural frequencies and modes of 2- and 3-layer beam configurations. Using the Euler-Bernoulli bending beam theory and free mode delamination, the governing differential equations are exploited and two beam finite elements are developed. The free bending vibration of three illustrative example problems, characterized by delamination zones of variable length, is investigated. The intact and defective beam natural frequencies and modes obtained from the proposed assembly/FEM beam formulations are presented along with the analytical results and those available in the literature

scholarly journals On the Finite Element Free Vibration Analysis of Delaminated Layered Beams: A New Assembly Technique

2021 ◽  
Author(s):  
Nicholas H. Erdelyi ◽  
Seyed M. Hashemi
Keyword(s):  
Finite Element ◽  
Natural Frequencies ◽  
Free Vibration Analysis ◽  
Beam Theory ◽  
Bending Vibration ◽  
Natural Frequencies And Modes ◽  
Layered Beams ◽  
Assembly Technique ◽  
Free Mode ◽  
Element Free

The dynamic analysis of flexible delaminated layered beams is revisited. Exploiting Boolean vectors, a novel assembly scheme is developed which can be used to enforce the continuity requirements at the edges of delamination region, leading to a delamination stiffness term. The proposed assembly technique can be used to form various beam configurations with through width delaminations, irrespective of the formulation used to model each beam segment. The proposed assembly system and the Galerkin Finite Element Method (FEM) formulation are subsequently used to investigate the natural frequencies and modes of 2- and 3-layer beam configurations. Using the Euler-Bernoulli bending beam theory and free mode delamination, the governing differential equations are exploited and two beam finite elements are developed. The free bending vibration of three illustrative example problems, characterized by delamination zones of variable length, is investigated. The intact and defective beam natural frequencies and modes obtained from the proposed assembly/FEM beam formulations are presented along with the analytical results and those available in the literature

scholarly journals On the Finite Element Free Vibration Analysis of Delaminated Layered Beams: A New Assembly Technique

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Nicholas H. Erdelyi ◽  
Seyed M. Hashemi
Keyword(s):  
Finite Element ◽  
Natural Frequencies ◽  
Free Vibration Analysis ◽  
Beam Theory ◽  
Bending Vibration ◽  
Natural Frequencies And Modes ◽  
Layered Beams ◽  
Assembly Technique ◽  
Free Mode ◽  
Element Free

The dynamic analysis of flexible delaminated layered beams is revisited. Exploiting Boolean vectors, a novel assembly scheme is developed which can be used to enforce the continuity requirements at the edges of delamination region, leading to a delamination stiffness term. The proposed assembly technique can be used to form various beam configurations with through-width delaminations, irrespective of the formulation used to model each beam segment. The proposed assembly system and the Galerkin Finite Element Method (FEM) formulation are subsequently used to investigate the natural frequencies and modes of 2- and 3-layer beam configurations. Using the Euler-Bernoulli bending beam theory and free mode delamination, the governing differential equations are exploited and two beam finite elements are developed. The free bending vibration of three illustrative example problems, characterized by delamination zones of variable length, is investigated. The intact and defective beam natural frequencies and modes obtained from the proposed assembly/FEM beam formulations are presented along with the analytical results and those available in the literature.

Free Vibration Analysis and Damage Identification of Beam-Like Structures Containing a Crack Based on the Extended Finite Element Method

2013 ◽  
Vol 831 ◽  
pp. 164-169
Author(s):  
Xiao Dong Zhang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Free Vibration ◽  
Cantilever Beam ◽  
Vibration Analysis ◽  
Extended Finite Element Method ◽  
Damage Identification ◽  
Free Vibration Analysis ◽  
Extended Finite Element ◽  
Element Method

A scheme is presented for the free vibration analysis of beam-like structures containing a crack with the extended finite element method (XFEM). The scheme is compared with the traditional scheme with the finite element method. The natural frequency of a cantilever beam is analyzed using both the methods and the results are compared. A new method for the damage identification of a cantilever beam containing a crack is then presented.

Pull-In Dynamics of Variable-Width Electrostatic Microactuators

2008 ◽  
Author(s):  
Manish M. Joglekar ◽  
Dnyanesh N. Pawaskar
Keyword(s):  
Constant Width ◽  
Actuation Voltage ◽  
Design Practice ◽  
Critical Amplitude ◽  
Electrostatically Actuated ◽  
Beam Geometry ◽  
Cantilevered Beam ◽  
Convex Geometries ◽  
Fixed Beam

Determination of pull-in parameters is vital in the design of electrostatically actuated microdevices. Moreover, it is important to devise some means to gain a control over the pull-in parameters in order to establish the customized microactuator design practice. In this paper, we analyze the influence of the beam geometry on the dynamic pull-in parameters of electrostatically actuated microbeams. Novel width functions are proposed for the microcantilever and the fixed-fixed beam, which smoothly vary the width of the microbeam along its length. We demonstrate the use of these width-functions by comparing six different microbeam geometries, three for cantilevered beam and three for fixed-fixed beam along with their constant width rectangular counterparts. All configurations are analyzed using an energy technique which gives an upper bound on the critical amplitude of the microbeam displacement, which is subsequently used to extract a lower bound on the applied voltage at the point of dynamic pull-in instability. For every case, a comparison is made between the static and the dynamic pull-in parameters. Results indicate a greater pull-in range for concave beam geometries, while the convex geometries exhibit a reduction in the pull-in range. Actuation voltage requirement is found to be proportional to the increase in the travel range. In all cases, the dynamic pull-in displacement is found to be greater than the static pull-in displacement, while the dynamic pull-in voltage is found to be less than the static pull-in voltage.

scholarly journals An investigation into the free vibration analysis of intact and defective laminated coposite beams subjected to combined axial force and end moment

2021 ◽  
Author(s):  
Mir Tahmaseb T. Kashani
Keyword(s):  
Finite Element ◽  
Free Vibration ◽  
Axial Force ◽  
Free Vibration Analysis ◽  
Numerical Data ◽  
Mode Shapes ◽  
Future Research ◽  
Frequency Dependent ◽  
Advantages And Disadvantages ◽  
Free Mode

This research is focusing on the bending-torsion coupled free vibration modeling as well as the analysis of intact and defective pre-stressed beams subjected to combined axial force and end moment. In the recent years, many studies have been conducted in an attempt to investigate the free vibration of pre-stressed beams using numerical and analytical techniques. However, despite their numerous applications, there is limited research done on pre-stressed beams subjected to both axial force and end moment in addition to the coupled behavior caused by the latter one. In the present study, current trends in the literature are critically examined, new models are proposed, and numerical and semi-analytical formulations are developed to find the natural frequencies and mode shapes of different pre-stressed slender beam configurations. The proposed methods are compared in terms of accuracy and convergence. Furthermore, the effects of axial force, end moment and delamination defect on the vibrational behavior of each model are also investigated. Four different general types of thin beams, including isotropic, layered, composite and delaminated beams, are modeled using traditional Finite Element Method (FEM) and frequency-dependent Dynamic Finite Element (DFE) technique. The DFE formulation is distinct from the conventional FEM by the fact that the former exploits frequency-dependent basis and shape functions of approximation space, whereas the polynomial ones are used in the latter method. With regard to layered beams, a novel layer-wise method is introduced for both DFE and FEM. Delaminated beam is also modeled using both ‘free mode’ and ‘constrained mode’ models showing that the continuity (both kinematic and force) conditions at delamination tips, in particular, play a large role in formulation of ‘free mode’ model. In this case, the defect is assumed to be a single-symmetric through the thickness delamination. However, the presented models and formulations could be readily extended to more general cases. Where available, the results were validated against existing limited experimental, analytical, and numerical data in literature. In addition, the investigated cases are modeled in the commercial finite element suite ANSYS® for further validation. Finally, general concluding remarks are made on the performance of the presented models and solution techniques, where the advantages and disadvantages of the proposed formulations as well as possible future research works are highlighted.

scholarly journals Free Vibration Analysis of an Un-cracked & Cracked Fixed Beam

2014 ◽  
Vol 11 (3) ◽  
pp. 76-83 ◽  
Author(s):  
Malay Quila ◽  
◽  
Prof. Samar Ch. Mondal ◽  
Prof. Susenjit Sarkar
Keyword(s):  
Free Vibration ◽  
Vibration Analysis ◽  
Free Vibration Analysis ◽  
Fixed Beam

Damage Identification of Cantilevered Beam Based on Multi-Resolution Analysis

2014 ◽  
Vol 487 ◽  
pp. 267-271
Author(s):  
Zhong Lang Zheng ◽  
Qin Da Zeng
Keyword(s):  
Damage Identification ◽  
Damage Factor ◽  
Factor Matrix ◽  
Crack Location ◽  
Damage Degree ◽  
Displacement Mode ◽  
Multi Resolution Analysis ◽  
Cantilevered Beam ◽  
Resolution Analysis ◽  
Frequency Band Energy

As a derivative parameter of the structural displacement mode, damage factor matrix was adopted to investigate the detection of structural crack location and damage. A methodological strategy by combination of the damage factor matrix and the wavelet multi-resolution analysis is presented in the paper, in order to identify structural damages of the cantilevered beam. The results show that damage can be identified by the damage factor matrix and the wavelet multi-resolution analysis, and the damage degree can be estimated by damage frequency band energy of the wavelet analysis. A reference to damage identification in current structure engineering is provided.

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