On the Actuation Authority of Adaptive Sandwich Beam with Composite Actuators: Coupled Finite Element Analysis

2012 ◽  
Vol 585 ◽  
pp. 332-336 ◽  
Author(s):  
K. Venkata Rao ◽  
S. Raja ◽  
T. Munikenche Gowda
Keyword(s):  
Numerical Experiments ◽  
Volume Fraction ◽  
Fiber Composite ◽  
Sandwich Beam ◽  
Beam Theory ◽  
Beam Element ◽  
Fiber Volume ◽  
Element Analysis ◽  
Active Fiber ◽  
Macro Fiber Composite

A two noded active sandwich beam element is formulated by employing layerwise Timoshenko’s beam theory. Displacement continuity conditions are imposed between different layers of the sandwich. This element is used to model an adaptive sandwich beam with macro-fiber composite (MFC) as extension actuator and shear actuated fiber composite (SAFC) as shear actuator. Influence of thickness and volume fraction of the active fiber (PZT-5A and single crystal PMN-PT) in the composite actuators on the actuation performance of the sandwich beam is investigated. Based on several numerical experiments, it is found that the PMN-PT based shear actuators give maximum actuation authority for the volume fraction of the fibers in the range of 80%-85%, whereas in case of PZT-5A based shear actuators the actuation authority remains maximum for the fiber volume fractions 80% and above.

scholarly journals Dynamic Analysis of Honeycomb Sandwich Beam with Multiple Debonds

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
B. Saraswathy ◽  
R. Ramesh Kumar ◽  
Lalu Mangal
Keyword(s):  
Analytical Solution ◽  
Transient Analysis ◽  
Sandwich Beam ◽  
Beam Theory ◽  
Beam Length ◽  
Honeycomb Core ◽  
Element Analysis ◽  
Fast Fourier Transform Analysis ◽  
Honeycomb Sandwich ◽  
Nonlinear Transient

Analytical formulation for the evaluation of frequency of CFRP sandwich beam with debond, following the split beam theory, generally underestimates the stiffness, as the contact between the honeycomb core and the skin during vibration is not considered in the region of debond. The validation of the present analytical solution for multiple-debond size is established through 3D finite element analysis, wherein geometry of honeycomb core is modeled as it is, with contact element introduced in the debond region. Nonlinear transient analysis is followed by fast Fourier transform analysis to obtain the frequency response functions. Frequencies are obtained for two types of model having single debond and double debond, at different spacing between them, with debond size up to 40% of beam length. The analytical solution is validated for a debond length of 15% of the beam length, and with the presence of two debonds of same size, the reduction in frequency with respect to that of an intact beam is the same as that of a single-debond case, when the debonds are well separated by three times the size of debond. It is also observed that a single long debond can result in significant reduction in the frequencies of the beam than multiple debond of comparable length.

Advanced Ferroelectric MFC Actuators: The Effect of Ferro-Elastic Domain Switching

2008 ◽  
Author(s):  
Uri Kushnir ◽  
Oded Rabinovitch
Keyword(s):  
Nonlinear Response ◽  
Domain Switching ◽  
Mechanical Load ◽  
Fiber Composite ◽  
Beam Element ◽  
Mechanical Loads ◽  
Active Structure ◽  
Elastic Domain ◽  
Macro Fiber Composite ◽  
Fiber Segment

Macro Fiber Composite (MFC) actuators, which are commonly integrated in modern smart structures, may be subjected to high levels of mechanical loads. Opposed to the electrical actuation, these loads are not always controlled or anticipated by the user. Thus, they may yield a response that is beyond the linear range due to a stress induced ferro-elastic domain switching. In this paper, the phenomenon of domain switching and mechanical depolarization in the MFC actuator and the resulting degradation of the actuation capabilities are investigated. As an illustrative numerical example, the response of MFC layers in an active beam element is analyzed. Emphasis is placed on the location of the fiber segment along the active beam with a distinction between the compressed and the tensed layers. The results highlight the range of effects associated with the potential nonlinear response of the active structure under high levels of mechanical load.

Determination of the Directional Dependent In-Plane Thermal Conductivity of K63B12 Pitch-Fiber/Epoxy Composite

2004 ◽  
Author(s):  
Jessica N. McClay ◽  
Peter Joyce ◽  
Andrew N. Smith
Keyword(s):  
Thermal Conductivity ◽  
Thermal Management ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Epoxy Composite ◽  
Fiber Composite ◽  
Fiber Volume ◽  
State Technique ◽  
Fiber Composite Materials

Measurements of the in-plane thermal conductivity and the directional dependence of Mitsubishi K63B12 pitch-fiber/Epoxy composite from Newport Composites are reported. This composite is being explored for use in the Avanced Seal Delivery System for effective thermal management. The thermal conductivity was measured using a steady state technique. The experimental results were then compared to a model of the thermal conductivity based on the direction of the fibers. These estimates are based on the properties of the constituent materials and volume of fibers in the sample. Therefore the density and the fiber volume fraction were experimentally measured. The thermal conductivity is clearly greatest in the direction of the fibers and decreases as the fibers are rotated off axis. In the case of pitch fiber composite materials, the contribution of the fibers to the thermal conductivity dominates. The experimental data clearly followed the correct trends; however, the measured values were 25% to 35% lower than predicted.

scholarly journals An Efficient Beam Element Based on Quasi-3D Theory for Static Bending Analysis of Functionally Graded Beams

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2198 ◽  
Author(s):  
Hoang Nam Nguyen ◽  
Tran Thi Hong ◽  
Pham Van Vinh ◽  
Do Van Thom
Keyword(s):  
Transverse Shear ◽  
Volume Fraction ◽  
Beam Theory ◽  
Beam Element ◽  
Functionally Graded ◽  
Shear Stresses ◽  
Functionally Graded Beam ◽  
Transverse Shear Stresses ◽  
Power Law Index ◽  
Transverse Shear Strains

In this paper, a 2-node beam element is developed based on Quasi-3D beam theory and mixed formulation for static bending of functionally graded (FG) beams. The transverse shear strains and stresses of the proposed beam element are parabolic distributions through the thickness of the beam and the transverse shear stresses on the top and bottom surfaces of the beam vanish. The proposed beam element is free of shear-looking without selective or reduced integration. The material properties of the functionally graded beam are assumed to vary according to the power-law index of the volume fraction of the constituents through the thickness of the beam. The numerical results of this study are compared with published results to illustrate the accuracy and convenience rate of the new beam element. The influence of some parametrics on the bending behavior of FGM beams is investigated.

Fracture behavior of short-fiber reinforced materials

1992 ◽  
Vol 7 (11) ◽  
pp. 3120-3131 ◽  
Author(s):  
Michael Murat ◽  
Micha Anholt ◽  
H. Daniel Wagner
Keyword(s):  
Fracture Process ◽  
Fracture Behavior ◽  
Volume Fraction ◽  
Fiber Composite ◽  
Finite Size ◽  
Critical Length ◽  
Short Fiber ◽  
Fiber Volume ◽  
Linear Elastic ◽  
Fiber Reinforced Materials

A discrete model of springs with bond-bending forces is proposed to simulate the fracture process in a composite of short stiff fibers in a softer matrix. Both components are assumed to be linear elastic up to failure. We find that the critical fiber length of a single fiber composite increases roughly linearly with the ratio of the fiber elastic modulus to matrix modulus. The finite size of the lattice in the direction perpendicular to the fiber orientation considerably alters the behavior of the critical length for large values of the modulus ratio. The simulations of the fracture process reveal different fracture behavior as a function of the fiber content and length. We calculate the Young's modulus, fracture stress, and the strain at maximum stress as a function of the fiber volume fraction and aspect ratio. The results are compared with the predictions of other theoretical studies and experiments.

Application of Carbon Fiber-Based Composite for Electric Vehicle

2014 ◽  
Vol 896 ◽  
pp. 574-577 ◽  
Author(s):  
Miftahul Anwar ◽  
Indro Cahyono Sukmaji ◽  
Wisnu R. Wijang ◽  
Kuncoro Diharjo
Keyword(s):  
Mechanical Properties ◽  
Carbon Fiber ◽  
Glass Fiber ◽  
External Load ◽  
Volume Fraction ◽  
Fiber Composite ◽  
Impact Testing ◽  
Fiber Volume ◽  
Glass Fiber Composite ◽  
Hybrid Carbon

In the present work, we study how to improve mechanical properties of carbon fiber reinforced plastics (CFRP) in order to increase crashworthiness probability. Experimentally, hybrid carbon /glass fiber composite was made in order to get higher mechanical properties. As a results, with increasing carbon fiber volume fraction (% vol.), tensile strength and flexural strength of the composite are increased. Simulation of impact testing is also performed using data properties taken from the experiment with variation of impact forces on front bumper structure. By varying external load to the bumper, the result shows that higher thickness of hybrid carbon/glass fiber composite has always smaller stress values than thinner one. On the other hand, the displacement of hybrid carbon/glass car bumper increases linearly with increasing external load.

Light-Weighting Design of Eco-Power Automobile Chassis Made from Green Composite and its Topology Optimization in FEA

2011 ◽  
Vol 341-342 ◽  
pp. 183-188
Author(s):  
Bao Zhong Sun ◽  
Kun Luan ◽  
Bo Hong Gu ◽  
Xiao Meng Fang ◽  
Jia Jin Zhang
Keyword(s):  
Topology Optimization ◽  
Volume Fraction ◽  
Testing System ◽  
Ramie Fiber ◽  
Mechanical Behaviors ◽  
Green Composite ◽  
Main Bearing ◽  
Fiber Volume ◽  
Element Analysis ◽  
Ramie Yarn

Green composite made from ramie fabric and polypropylene (PP) is a kind of recyclable and environmental friendly material. Ramie fiber tows have relatively good mechanical properties comparing with other bast fibers, and hence the fabric woven by ramie yarn shows excellent in-plane mechanical behaviors. PP can be fully recovered and recycling used for its thermoplastic character. Ramie fabrics reinforced by PP have better shape formability and maintenance. In this paper, we proposed a plain weave in sample dobby loom, and reinforced four laid-layers together by PP particle through hot pressing. The mechanical behaviors of the ramie-PP composite were tested by MTS-810 Material Testing System in weft and warp directions separately which were essential parameters to the following topology optimization in finite element analysis (FEA) software. A body of eco-power automobile consisting of shell and chassis was original designed in Pro/E® Wildfire 5.0. For the chassis is the main bearing structure, it is an important part in the eco-power automobile body and was chosen to be topology optimized. Fiber volume fraction and structure optimization of the chassis model are evaluated and simulated to guide the material formation of manufacture progress.

scholarly journals TENSILE TEST ANALYSIS OF NATURAL FIBER REINFORCED COMPOSITE

2014 ◽  
pp. 148-152
Author(s):  
G. VELMURUGAN ◽  
D. VADIVEL ◽  
R. ARRAVIND ◽  
A. MATHIAZHAGAN ◽  
S.P. VENGATESAN
Keyword(s):  
Natural Fiber ◽  
Volume Fraction ◽  
Fiber Composite ◽  
Tensile Load ◽  
Experimental Result ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Test Analysis ◽  
Reinforced Composite ◽  
Strain Stress

This project mainly deals with analysis of tensile properties of Palmyra fiber Reinforced Epoxy Composite that is suitable for automobile application. First, the property of material was obtained on the basis of some assumptions (i.e., Rule of Mixture) and was modeled with reference to ASTM D638. Here the simulation was carried out on specimen under different fiber volume fraction and fiber length. The present work includes the Analysis of Palmyra Fiber Reinforced Epoxy Composites using FEA with various fiber volume fractions and these results were validated with the experimental result. The tensile property of Palmyra fiber composite material can be obtained by using tensometer.During the tensile load, the maximum strain, stress and displacement were obtained and, then this experimental result was compared with the analytical results and the error percentage of these results were calculated.

Finite Element Analysis of Interfacial Debonding Damage in Fiber-Reinforced Ceramic Matrix Composites

2007 ◽  
Vol 546-549 ◽  
pp. 1555-1558
Author(s):  
Chun Jun Liu ◽  
Yue Zhang ◽  
Da Hai Zhang ◽  
Zhong Ping Li
Keyword(s):  
Finite Element ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Interfacial Debonding ◽  
Matrix Composites ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Element Analysis

In this paper the composite fracture process has been simulated via the finite element method. A micromechanics model was developed to predict the stress-strain response of a SiO2f/ SiO2 composite explicitly accounting for the local damage mechanisms such as fiber fracture and interfacial debonding. The effects of interfacial strength and fiber volume fraction on the toughness of fiber-reinforced ceramic matrix composites were investigated. The results showed that the composite failure behaviors correlated with the interface strength, which could achieve an optimum value for the elevation of the composite toughness. The increase of fiber volume fraction can make more toughening contributions.

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