scholarly journals Through-the-thickness stress distributions near edges of composite laminates using stress recovery scheme and third order shear and normal deformable theory

2015 ◽  
Vol 131 ◽  
pp. 397-413 ◽  
Author(s):  
P.H. Shah ◽  
R.C. Batra
Keyword(s):  
Composite Laminates ◽  
Stress Recovery ◽  
Stress Distributions ◽  
Third Order ◽  
Recovery Scheme

Stress Recovery in Composite Laminates Including Geometrically Nonlinear and Dynamic Effects

AIAA Journal ◽  
2016 ◽  
Vol 54 (8) ◽  
pp. 2521-2529 ◽  
Author(s):  
Timothy B. Hartman ◽  
Michael W. Hyer ◽  
Scott W. Case
Keyword(s):  
Composite Laminates ◽  
Stress Recovery ◽  
Geometrically Nonlinear ◽  
Dynamic Effects

Analytical Solutions of Refined Plate Theories of Cross-Ply Composite Laminates

1991 ◽  
Vol 113 (4) ◽  
pp. 570-578 ◽  
Author(s):  
A. A. Khdeir ◽  
J. N. Reddy
Keyword(s):  
Boundary Conditions ◽  
Exact Solutions ◽  
Composite Laminates ◽  
Laminated Composite ◽  
Composite Plates ◽  
Third Order ◽  
State Space Approach ◽  
Various Boundary Conditions ◽  
Shear Deformation Theories ◽  
Space Approach

Exact solutions of rectangular laminated composite plates with different boundary conditions are studied. The Le´vy-type solutions of the classical, first-order and third-order shear deformation theories are developed using the state-space approach. The finite-element solutions for the three theories are also computed and compared with the exact solutions for various boundary conditions.

Optimization of Wind-Up Tension of Webs Preventing Wrinkles and Slippage

2009 ◽  
Vol 131 (5) ◽  
Author(s):  
Hiromu Hashimoto
Keyword(s):  
Nonlinear Model ◽  
Optimization Technique ◽  
Air Entrainment ◽  
Optimization Method ◽  
Radial Coordinate ◽  
Stress Distributions ◽  
Third Order ◽  
Tangential Stresses ◽  
Mathematical Programming Method ◽  
Order Spline

This paper describes the optimization method of wind-up tension to prevent wound roll defects, mainly star defects and slippage, based on the optimum design technique. Hakiel’s nonlinear model with air entrainment effects is applied to analyze in-roll stress distributions in the radial and tangential directions (1987, “Nonlinear Model for Wound Roll Stresses,” Tappi J., 70(5), pp. 113–117). It is well known experimentally that a decrease in the wind-up tension prevents star defects due to negative tangential stress under winding. Thus, in the present optimization method, wind-up tension is gradually decreased in the radial direction to minimize the averaged value of tangential stresses under the constraint of non-negative tangential stresses. Furthermore, the relation of the slippage between wound film layers and in-roll stress of a roll is considered. Successive quadratic programming, which is the typical mathematical programming method, is used as the optimization technique. Wind-up tension is expressed by the third-order spline curve of a radial coordinate. The liner function with respect to the radial coordinate is used as the original wind-up tension. The optimized wind-up tensions are obtained for various winding conditions, and we confirmed that the in-roll stress distributions were very much improved for preventing wrinkles and slippage by the optimization method proposed.

Elastic Damage Analysis of Interlaminar Stress Distributions in Symmetrical Composite Laminates with Edge Delamination Cracks

1994 ◽  
Vol 208 (1) ◽  
pp. 1-11 ◽  
Author(s):  
C L Chow ◽  
F Yang
Keyword(s):  
Composite Laminates ◽  
Three Dimensional ◽  
Tensile Load ◽  
Uniaxial Tensile ◽  
Stress Distributions ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Edge Delamination ◽  
Delamination Cracks

This paper is intended to present a study of elastic-damaged behaviour of symmetrical composite laminates with edge delamination cracks subjected to uniformly applied uniaxial tensile load. The response of composite laminates is investigated by a quasi-three-dimensional finite element analysis including the damage characterization of constituent plies. Of principal concern are the effects of edge delamination cracks as well as the influence of damage on stress distributions in graphite/epoxy [0/90°]s, [90/0°]s and [±45°], laminates. The computed results between the behaviours of laminates with stiffness damage consideration and those of geometrically similar laminates without stiffness damage are compared and the significance of damage in stress analysis of fibre-reinforced composite materials is elucidated.

Three-dimensional stress distributions in hexagonal aeolotropic crystals

1948 ◽  
Vol 44 (4) ◽  
pp. 522-533 ◽  
Author(s):  
H. A. Elliott ◽  
N. F. Mott
Keyword(s):  
Harmonic Functions ◽  
Three Dimensional ◽  
Transversely Isotropic ◽  
Quadratic Equation ◽  
Stress Distributions ◽  
Third Order ◽  
Isotropic Solid ◽  
Single Stress ◽  
Image Position ◽  
Special Case

The conditions for equilibrium in an elastically stressed hexagonal aeolotropic medium (transversely isotropic) are formulated, and solutions are found in terms of two ‘harmonic’ functions ø1, ø2, which are solutions ofν1, ν2 being the roots of a certain quadratic equation.It is also shown that in the case of axially symmetrical stress systems the solution may be expressed in terms of the third-order differential coefficients of a single stress function Φ.The solutions for an isotropic medium may be deduced as a special case.The problems of nuclei of strain in such a hexagonal solid are solved, and the results for zinc and magnesium contrasted with those for an isotropic solid.

A Comparison of the Strains Due to Edge Cracks and Cuts of Finite Width With Applications to Residual Stress Measurement

1993 ◽  
Vol 115 (2) ◽  
pp. 220-226 ◽  
Author(s):  
W. Cheng ◽  
I. Finnie
Keyword(s):  
Stress Measurement ◽  
Arbitrary Distribution ◽  
Finite Width ◽  
Stress Distributions ◽  
Power Functions ◽  
Third Order ◽  
Near Surface ◽  
Surface Residual Stresses ◽  
Edge Cracks ◽  
Loaded Crack

The strains on the surface near a loaded crack or cut are compared for cuts of different width to depth ratios. General solutions are obtained for an arbitrary distribution of normal and shear tractions on the faces of the crack or cut. Numerical results are presented for normal stress distributions which vary with distance from the surface as power functions of zero to third order. The results are useful for measurement of near surface residual stresses and should also be of value for crack compliance measurements of stress intensity factors.

Third-Order Polynomials Model for Analyzing Multilayer Hard/Soft Materials in Flexible Electronics

2016 ◽  
Vol 83 (8) ◽  
Author(s):  
Xianhong Meng ◽  
Boya Liu ◽  
Yu Wang ◽  
Taihua Zhang ◽  
Jianliang Xiao
Keyword(s):  
Mechanical Properties ◽  
Flexible Electronics ◽  
Virtual Work ◽  
Soft Materials ◽  
Normal Strain ◽  
Stress Distributions ◽  
Third Order ◽  
Inorganic Semiconductors ◽  
Design And Optimization ◽  
Good Agreement

In flexible electronics, multilayer hard/soft materials are widely used to utilize both the superior electrical properties of inorganic semiconductors and robust mechanical properties of polymers simultaneously. However, the huge mismatch in mechanical properties of the hard and soft materials makes mechanics analysis challenging. We here present an analytical model to study the mechanics of multilayer hard/soft materials in flexible electronics. Third-order polynomials are adopted to describe the displacement field, which can be used to easily derive both strain and stress fields. Then, the principle of virtual work was used to derive the governing equations and boundary conditions, which can be solved numerically. Two types of loadings, pure bending and transverse shear, are studied. The normal strain distributions along thickness direction in the bimaterial regions clearly show zigzag profiles, due to the huge mismatch in the mechanical properties of the hard and soft materials. The effect of very different mechanical properties of the hard and soft materials on shear stress distributions can also be predicted by this model. The results from this analytical mode show good agreement with finite-element modeling (FEM). This model can be useful in systems with multilayer hard/soft materials, to predict mechanical behavior and to guide design and optimization.

scholarly journals Geometrically Nonlinear Stress Recovery in Composite Laminates

AIAA Journal ◽  
2012 ◽  
Vol 50 (5) ◽  
pp. 1156-1168 ◽  
Author(s):  
Timothy B. Hartman ◽  
Michael W. Hyer ◽  
Scott W. Case
Keyword(s):  
Composite Laminates ◽  
Stress Recovery ◽  
Geometrically Nonlinear ◽  
Nonlinear Stress
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