Simplified prediction of stresses in transversely isotropic composite plates under Hertzian contact load

2006 ◽  
Vol 73 (1) ◽  
pp. 70-77 ◽  
Author(s):  
Robin Olsson ◽  
Sören Nilsson
Keyword(s):  
Composite Plates ◽  
Transversely Isotropic ◽  
Hertzian Contact ◽  
Contact Load ◽  
Isotropic Composite

Transient Response of Transversely Isotropic Composite Plates to a Point Source

2005 ◽  
Vol 73 (2) ◽  
pp. 338-341 ◽  
Author(s):  
A. Mahmoud ◽  
A. H. Shah ◽  
S. B. Dong
Keyword(s):  
Steady State ◽  
Transient Response ◽  
Three Dimensional ◽  
Composite Plates ◽  
Transversely Isotropic ◽  
Point Load ◽  
Wave Number ◽  
Isotropic Composite ◽  
Steady State Responses ◽  
State Responses

In this paper, transient three-dimensional response of a transversely isotropic composite plate to a time varying point load is efficiently computed by reducing the elastodynamic equation through integral and coordinate transformations to a series of two-dimensional problems, each associated with a plane wave along a given direction in the plate. Discrete equations of a semi-analytical finite element model are solved for the thickness profile eigendata at a given frequency. Three-dimensional steady state responses in the wave number domain are formed by summing contributions from eigenmodes over propagation directions. The transient response is obtained by a numerical integration of inverse Fourier time transform of these steady state responses. Present results showed good agreement with data reported in the literature and confirmed previously observed phenomena.

The Elastic Characterization of Composite Based on Ultrasonic Waves

2021 ◽  
Author(s):  
Y. H. Park ◽  
J. Dana
Keyword(s):  
Composite Materials ◽  
Fatigue Failure ◽  
Elastic Constants ◽  
Material Properties ◽  
Weight Ratio ◽  
Transversely Isotropic ◽  
Ultrasonic Waves ◽  
Material Strength ◽  
Isotropic Composite

Abstract Anisotropic composite materials have been extensively utilized in mechanical, automotive, aerospace and other engineering areas due to high strength-to-weight ratio, superb corrosion resistance, and exceptional thermal performance. As the use of composite materials increases, determination of material properties, mechanical analysis and failure of the structure become important for the design of composite structure. In particular, the fatigue failure is important to ensure that structures can survive in harsh environmental conditions. Despite technical advances, fatigue failure and the monitoring and prediction of component life remain major problems. In general, cyclic loadings cause the accumulation of micro-damage in the structure and material properties degrade as the number of loading cycles increases. Repeated subfailure loading cycles cause eventual fatigue failure as the material strength and stiffness fall below the applied stress level. Hence, the stiffness degradation measurement can be a good indication for damage evaluation. The elastic characterization of composite material using mechanical testing, however, is complex, destructive, and not all the elastic constants can be determined. In this work, an in-situ method to non-destructively determine the elastic constants will be studied based on the time of flight measurement of ultrasonic waves. This method will be validated on an isotropic metal sheet and a transversely isotropic composite plate.

An Analytical Modeling for Effective Thermal Conductivity of Multi-Phase Transversely Isotropic Fiberous Composites Using Generalized Self-Consistent Method

2012 ◽  
Vol 249-250 ◽  
pp. 904-909 ◽  
Author(s):  
Syed Aadil Hassan ◽  
Hassaan Ahmed ◽  
Asif Israr
Keyword(s):  
Thermal Conductivity ◽  
Effective Thermal Conductivity ◽  
Composite System ◽  
Volume Fraction ◽  
Transversely Isotropic ◽  
Balance Principle ◽  
Isotropic Composite ◽  
Self Consistent ◽  
Consistent Method ◽  
Multi Phase

In this paper a theoretical relationship for the effective thermal conductivity of a multiphase transversely isotropic composite system is obtained. The Generalized Self-Consistent Method and simple energy balance principle is employed to derive a more appropriate model. In the derivation, it is assumed that the orientation of fiber within the transversely isotropic composite system is unidirectional and surrounded by two different phases of porous and matrix phase. A combined effect of these three different phases on the effective thermal conductivity of the composite system in transverse direction is studied. The effect of the interfacial contact conductance between the fibers and porous medium is also considered. Results of effective thermal conductivity are plotted against volume fraction and conductance which shows extremely good agreement.

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