Stress Fields in a Continuous Fiber Composite With a Variable Interphase Under Thermo-Mechanical Loadings

1994 ◽  
Vol 116 (3) ◽  
pp. 367-377 ◽  
Author(s):  
Yozo Mikata
Keyword(s):  
Carbon Fiber ◽  
Stress Field ◽  
Fiber Composite ◽  
Closed Form Solution ◽  
Form Solution ◽  
Stress Fields ◽  
Circular Cylinders ◽  
Stress Distributions ◽  
Continuous Fiber ◽  
Al 6061

Stress fields in a continuous fiber composite with a variable interphase subjected to thermomechanical loadings are studied by using a four concentric circular cylinders model. An exact closed form solution is obtained for the stress field in the interphase in a series form using Frobenius method in a certain case. Numerical results are presented for FP fiber/Al 6061 composite with interphase, and carbon fiber/Al 6061 composite with interphase. It is found that the variableness of the thermoelastic constants in the interphase has significant effects on the stress distributions in the interphase. Therefore, this will, in turn, affect the initiation of cracks in the interphase.

Eigenstresses in Anisotropic Films

1991 ◽  
Vol 239 ◽  
Author(s):  
Ferdinando Auricchio ◽  
Mauro Ferrari
Keyword(s):  
Stress Field ◽  
Experimental Determination ◽  
Three Dimensional ◽  
Closed Form Solution ◽  
Form Solution ◽  
Ceramic Film ◽  
Stress States ◽  
Resultant Stress ◽  
Structural Theories

ABSTRACTA closed-form solution for a macroscopically homogeneous, fully anisotropie layer subject to non-uniform through-thickness eigenstrain is presented, and employed in determining the three-dimensional deformation and stress states of a thermally loaded ceramic film with microstructure-induced macroscopic anisotropy. The resultant stress field is compared with those that could be deduced by experimental determination of the curvature and the classical structural theories.

Closed-form solution of Cattaneo equation including volumetric source in relation to laser short-pulse heating

2011 ◽  
Vol 89 (7) ◽  
pp. 761-767 ◽  
Author(s):  
H. Al-Qahtani ◽  
B.S. Yilbas
Keyword(s):  
Stress Field ◽  
Closed Form ◽  
Short Pulse ◽  
Closed Form Solution ◽  
Transformation Method ◽  
Substrate Material ◽  
Form Solution ◽  
Cooling Period ◽  
Wave Nature ◽  
Heating Model

The wave nature of the heating model is considered, incorporating the Cattaneo equation with the presence of a volumetric heat source. The volumetric heat generation resembles the step input laser short-pulse intensity. The governing of the heat equation is solved analytically using the Laplace transformation method. The stress field generated due to thermal contraction and expansion of the substrate material is formulated and the closed-form solution is presented. It is found that the wave nature of the heating is dominant during the period of the irradiated short-pulse; however, in the late cooling period, the wave nature of heating is replaced by diffusional heat conduction, governed by Fourier’s law. The stress field during the heating cycle is compressive and becomes tensile in the cooling cycle.

A Numerical Procedure for Designing Profiled Rolling Elements

1976 ◽  
Vol 98 (4) ◽  
pp. 547-551 ◽  
Author(s):  
K. P. Oh ◽  
E. G. Trachman
Keyword(s):  
Closed Form Solution ◽  
Numerical Procedure ◽  
Potential Method ◽  
Form Solution ◽  
Geometric Constraints ◽  
Stress Distributions ◽  
Elastic Bodies ◽  
Rolling Elements ◽  
Quadratic Programming Method ◽  
Quadratic Surfaces

A numerical procedure is developed for studying the pressure and stress distributions resulting from the contact of two elastic bodies. The pressure distribution is obtained by a quadratic programming method such that the resulting displacements satisfy the geometric constraints of the contact problem, and the bodies are in a state of minimum potential energy. The potential method is used to calculate the subsurface stresses due to a constant pressure over a rectangular element. The stresses due to the contact pressure are then obtained by superposition of the contributions of all the elements in the contact area. A small number of elements (5 × 5) provides pressure and stress solutions within two percent of the closed-form solution for quadratic surfaces. For surfaces with abrupt changes in geometry, more elements are required. This procedure can be used to locate an optimum profile for rolling element bearings.

Elastic-Plastic Stress Field in a Coated Continuous Fibrous Composite Subjected to Thermomechanical Loading

1999 ◽  
Vol 66 (3) ◽  
pp. 750-757 ◽  
Author(s):  
L. You ◽  
S. Long ◽  
L. Rohr
Keyword(s):  
Stress Field ◽  
Governing Equation ◽  
Yield Criterion ◽  
Fibrous Composite ◽  
Closed Form Solution ◽  
Metallic Matrix ◽  
Form Solution ◽  
Concentric Cylinders ◽  
The Matrix ◽  
Strain Relationship

A micromechanics investigation was performed in the present work to analyze the stress field in a coated continuous fibrous composite subjected to thermal and mechanical loading based on a four-concentric-cylinders model. A temperature-independent stress-plastic strain relationship for the metallic matrix and coating layer with linear strain-hardening behaviour were introduced. Tresca’s yield criterion and the associated flow law were employed to derive the governing equation of the coating and matrix. The closed-form solution of the governing equation was obtained. Some numerical examples were given. The numerical results indicate that the plasticity of the coating greatly decreases the circumferential and axial stresses in the coating itself, but has very limited influence on the stresses in other constituents of the composite. The plasticity of the matrix imposes no significant influence on all the stresses in the composite.

scholarly journals Design of Low Cost Carbon Fiber Composites via Examining the Micromechanical Stress Distributions in A42 Bean-Shaped versus T650 Circular Fibers

2021 ◽  
Vol 5 (11) ◽  
pp. 294
Author(s):  
Imad Hanhan ◽  
Michael D. Sangid
Keyword(s):  
Carbon Fiber ◽  
Carbon Fibers ◽  
Fiber Composite ◽  
Low Cost ◽  
Complex Loading ◽  
Fiber Composites ◽  
Production Costs ◽  
Carbon Fiber Composites ◽  
Stress Distributions ◽  
Carbon Fiber Composite

Recent advancements have led to new polyacrylonitrile carbon fiber precursors which reduce production costs, yet lead to bean-shaped cross-sections. While these bean-shaped fibers have comparable stiffness and ultimate strength values to typical carbon fibers, their unique morphology results in varying in-plane orientations and different microstructural stress distributions under loading, which are not well understood and can limit failure strength under complex loading scenarios. Therefore, this work used finite element simulations to compare longitudinal stress distributions in A42 (bean-shaped) and T650 (circular) carbon fiber composite microstructures. Specifically, a microscopy image of an A42/P6300 microstructure was processed to instantiate a 3D model, while a Monte Carlo approach (which accounts for size and in-plane orientation distributions) was used to create statistically equivalent A42/P6300 and T650/P6300 microstructures. First, the results showed that the measured in-plane orientations of the A42 carbon fibers for the analyzed specimen had an orderly distribution with peaks at |ϕ|=0∘,180∘. Additionally, the results showed that under 1.5% elongation, the A42/P6300 microstructure reached simulated failure at approximately 2108 MPa, while the T650/P6300 microstructure did not reach failure. A single fiber model showed that this was due to the curvature of A42 fibers which was 3.18 μm−1 higher at the inner corner, yielding a matrix stress that was 7 MPa higher compared to the T650/P6300 microstructure. Overall, this analysis is valuable to engineers designing new components using lower cost carbon fiber composites, based on the micromechanical stress distributions and unique packing abilities resulting from the A42 fiber morphologies.

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