Analytical model for prediction of the damping loss factor of composite materials

1992 ◽  
Vol 13 (3) ◽  
pp. 179-190 ◽  
Author(s):  
Roger M. Crane ◽  
John W. Gillespie
Keyword(s):  
Composite Materials ◽  
Analytical Model ◽  
Loss Factor ◽  
Damping Loss Factor

Studies on Properties of Epoxy Resin Base Piezoelectricity Damping Carbon Fiber Composite Materials

2012 ◽  
Vol 508 ◽  
pp. 271-275
Author(s):  
Yan Qin ◽  
Shi Wei Zhao ◽  
Bi Fang Dai ◽  
Qi Lin Mei ◽  
Zhi Xiong Huang
Keyword(s):  
Composite Materials ◽  
Epoxy Resin ◽  
Loss Factor ◽  
Fiber Composite ◽  
Resin Matrix ◽  
Carbon Fiber Composite ◽  
Loss Mechanism ◽  
Beam Method ◽  
Damping Loss Factor ◽  
Damping Materials

Damping Materials Have Been Wildly Used in Aerospace, Traffic, Construction Fields and so on. The Piezo-Damping Materials Have Received much Attention due to the Novel Energy Loss Mechanism. In this Paper, Piezo-Damping Composite Materials Were Prepared from the Epoxy Resin (EP) as the Resin Matrix, Nano Lead Titanate (Nano-PT) Ceramics as Piezoelectric Material and Chopped Carbon Fibers (CF) as Conductive Materials. The Mechanical and Damping Properties of the Composites Were Analyzed by Mechanics Test, DMA and Vibration Beam Method. The Results Showed that when the Nano-PT Content Was 60% of EP and CF Content Was 0.25% of EP, the Composite Got the Better Mechanical Properties. Form DMA, the Loss Factor (tanδ) Peak Reached 0.58. Damping Temperature Range △T (tanδ>0.3) Was about 36.3°C. In Comparison, Damping Loss Factor Measured by Vibration Beam Method Was 0.82.

A New Methodology for the Accurate and Consistent Identification of Modal Parameters Using Multi-FRF Analysis

1995 ◽  
Author(s):  
R. M. Lin ◽  
S.-F. Ling
Keyword(s):  
Eigenvalue Problem ◽  
Loss Factor ◽  
Frequency Response Function ◽  
Natural Frequencies ◽  
Identification Problem ◽  
Modal Parameters ◽  
Frequency Range ◽  
Case Examples ◽  
Measured Frequency Response ◽  
Damping Loss Factor

Abstract A new method for the estimation of modal parameters is presented in this paper. Unlike the majority of the existing methods which involve complicated curve fitting and interpolative procedures, the proposed method calculates the modal parameters by solving eigenvalue problem of an equivalent eigensystem derived from measured frequency response function (FRF) data. It is developed based on the practical assumption that only one incomplete column of the FRF matrix of the test structure has been measured in a frequency range of interest. All the measured FRFs are used simultaneously to construct the equivalent eigensystem matrices from which natural frequencies, damping loss factor and modeshape vectors of interest can be directly solved. Since the identification problem is reduced to an eigenvalue problem of an equivalent system, natural frequencies and damping loss factors identified are consistent. Further procedures for normalizing the identified eigenvectors so that they become mass-normalized are developed. Numerical case examples are given to demonstrate the practicality of the proposed method and results obtained are indeed very promising. It is believed that with the availability of such identification method, modal analysts’ dream of intelligent and full automatic modal analysis will become a reality.

The Backing Design in the Free Damping Cylindrical Shell Damping Test

2013 ◽  
Vol 437 ◽  
pp. 475-480
Author(s):  
Bang Hui Yin ◽  
Min Qing Wang
Keyword(s):  
Cylindrical Shell ◽  
Energy Method ◽  
Design Problem ◽  
Loss Factor ◽  
Cylindrical Shells ◽  
Harmonic Response ◽  
Different Types ◽  
Damping Loss Factor

The ANSYS harmonic response results are post-processed with the energy method to obtain the damping loss factor (DLF) of different types of free damping structures. Firstly, the DLF of free damping cylindrical shell in air is compared with DLF of free damping plate in air. Secondly, the DLF of free damping cylindrical shell with stiffened ribs in air is compared with that without stiffened ribs in air. Thirdly, the DLF of free damping cylindrical shell in water is compared with the DLF of free damping plate in water. Fourthly, the DLF of free damping cylindrical shell with stiffened ribs in water is compared with that without stiffened ribs in water. In the end, based on the above analysis, the backing design problem in air and water are discussed. Studies have shown that: DLF of free damping cylindrical shell is close to that of free damping plate in air; DLF of free damping cylindrical shell with stiffened ring ribs is close to that without stiffened ring ribs in air; When testing free damping cylindrical shells DLF in air, plate with the same thickness can be used as the backing; DLF of free damping plate is close to that of free damping cylindrical shell in water; DLF of free damping cylindrical shell with stiffened ring ribs is close to that without stiffened ring ribs in water; When testing free damping cylindrical shells DLF in water, plate with the same thickness can be used as the backing.

Experimental Determination of the Damping Loss Factor of Highly Damped Ribbed-Stiffened Panels

2008 ◽  
Author(s):  
Jesús Ortiz Martinez ◽  
Márcio Calçada ◽  
Roberto Jordan ◽  
Samir N. Y. Gerges
Keyword(s):  
Experimental Determination ◽  
Loss Factor ◽  
Stiffened Panels ◽  
Damping Loss Factor

Measurement of SEA damping loss factor for complex structures

2008 ◽  
Vol 123 (5) ◽  
pp. 3060-3060 ◽  
Author(s):  
Maxime Bolduc ◽  
Noureddine Atalla
Keyword(s):  
Loss Factor ◽  
Complex Structures ◽  
Damping Loss Factor

A Robust Testing Method for Determination of the Damping Loss Factor of Composites

1992 ◽  
Vol 14 (2) ◽  
pp. 70
Author(s):  
WS Johnson ◽  
JE Masters ◽  
TK O'Brien ◽  
RM Crane ◽  
JW Gillespie
Keyword(s):  
Loss Factor ◽  
Testing Method ◽  
Robust Testing ◽  
Damping Loss Factor

Study on the Properties of Microwave Curing Epoxy Resin/Nano-Fe Composite Materials

2010 ◽  
Vol 26-28 ◽  
pp. 356-359 ◽  
Author(s):  
Xiao Feng Sun ◽  
Shi Ning Ma ◽  
Jia Wu He ◽  
Nai Shu Zhu
Keyword(s):  
Composite Materials ◽  
Microwave Irradiation ◽  
Epoxy Resin ◽  
Loss Factor ◽  
Mechanical Analysis ◽  
Resin Matrix ◽  
Absorption Properties ◽  
Microwave Absorption Properties ◽  
Microwave Curing ◽  
Scanning Electron

Nano-Fe particles were selected as microwave-absorber, and added in the epoxy resin. Epoxy resin/nano-Fe composite materials were cured by microwave irradiation and heating. Vector network analysis, dynamic mechanical analysis(DMA) and scanning electron microscope(SEM) were used to study the curing behaviors of composite materials under the different curing ways. Results show that the dielectric constant(εr) and the dielectric loss factor(tanδ) of the epoxy resin increased obviously when nano-Fe particles were added, and microwave absorption properties of epoxy resin/nano-Fe composite materials improved greatly with increasing contents of nano-Fe particles. DMA results indicate that the storage modulus (E’) and glass transition temperature(Tg) of epoxy resin samples with nano-Fe particles were higher than those without nano-Fe particles. The microstructure and phase composition of the samples were studied by SEM and EDX. Results show that nano-Fe particles were homogeneously dispersed in the epoxy resin matrix under microwave irradiation, which implies improved strength and toughness of epoxy resin/nano-Fe composite materials.

Sign in / Sign up

Export Citation Format

Share Document