Design procedure for reducing the stress concentration around circular holes in laminated composites

Composites ◽  
1995 ◽  
Vol 26 (12) ◽  
pp. 815-828 ◽  
Author(s):  
Rosen T. Tenchev ◽  
Magne K. Nygard ◽  
Andreas Echtermeyer
Keyword(s):  
Stress Concentration ◽  
Laminated Composites ◽  
Design Procedure ◽  
Circular Holes

Mechanical Behavior of Laminated Composites with Circular Holes

2013 ◽  
Vol 550 ◽  
pp. 1-8 ◽  
Author(s):  
Habib Achache ◽  
Benali Boutabout ◽  
Djamel Ouinas
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Composite Structures ◽  
Laminated Composites ◽  
Three Dimensional ◽  
Laminated Composite ◽  
Element Formulation ◽  
Composites Materials ◽  
Circular Holes ◽  
Fibers Orientation

This paper presents a numerical method for the evaluation of the stress concentration factor (SCF) in three dimensional laminated composites under mechanical loads. The proposed method uses the finite element formulation. The composites materials based on the epoxy matrix and reinforcing fibers are extensively used in aircraft structures due to their high specific characteristics. However, the withstanding of composite structures can be significantly reduced by the addition of geometric singularities, such as perforations or notches. To Analyses the stress concentration around geometrical notches, several studies as analytical, numerical and experimental techniques are available. The stress distribution in a laminated composite plate with the presence of a circular hole was investigated using the finite element method. In order, the results obtained by this study are compared with those reported in literature. The aim of this analysis is to evaluate numerically the factor of stress concentration under the influence of several parameters such as fibers orientation, the mechanical characteristics of composites and the distance between notches of cross-laminated.

Stress Concentration Factors in Auxetic Rods and Plates

2013 ◽  
Vol 394 ◽  
pp. 134-139 ◽  
Author(s):  
Teik Cheng Lim
Keyword(s):  
Stress Concentration ◽  
Circumferential Stress ◽  
Axial Direction ◽  
Thin Plates ◽  
Auxetic Materials ◽  
Circular Holes ◽  
Concentration Factors ◽  
Stress Concentration Factors ◽  
Future Work ◽  
Poissons Ratio

Auxetic materials are solids that possess negative Poissons ratio. Although rare, such materials do occur naturally and also have been artificially produced. Due to their unique properties, auxetic materials have been extensively investigated for load bearing applications including in biomedical engineering and aircraft structures. This paper considers the effect of Poissons ratio on the stress concentration factors on rods with hyperbolic groove and large thin plates with circular holes and rigid inclusions. Results reveal that the use of auxetic materials is useful for reducing stress concentration in the maximum circumferential stress of the rods with grooves, and in plates with circular holes and rigid inclusions. However, the use of auxetic materials increases the stress concentration in the axial direction of the rod. Therefore a procedure to accurately select and/or design materials with precise negative Poissons ratio for optimal design is suggested for future work.

The Stress Concentration Factors in Cylindrical Tubes with Transverse Circular Holes

1959 ◽  
Vol 10 (4) ◽  
pp. 326-344 ◽  
Author(s):  
H. T. Jessop ◽  
C. Snell ◽  
I. M. Allison
Keyword(s):  
Stress Concentration ◽  
Maximum Stress ◽  
Stress System ◽  
Complete Knowledge ◽  
Geometrical Shapes ◽  
Cylindrical Tubes ◽  
Circular Holes ◽  
Concentration Factors ◽  
Stress Concentration Factors ◽  
Better Than

The “frozen stress” techniques of photoelasticity can give a complete knowledge of the stress, system in a solid body, but the examination of the stresses requires more time and care than in corresponding flat plate tests. In tests on tubes with transverse circular holes, sponsored by The Royal Aeronautical Society, all practicable geometrical shapes are examined and the maximum stress is measured in tension, bending and torsion. The results are comprehensive and show the inadequacy of previous results. In all cases the maximum stress occurs inside the bore of the hole. The accuracy of all the graphs of stress concentration factors is better than five per cent.

scholarly journals Modeling of Size Effects in Bending of Perforated Cosserat Plates

2017 ◽  
Vol 2017 ◽  
pp. 1-19 ◽  
Author(s):  
Roman Kvasov ◽  
Lev Steinberg
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Numerical Study ◽  
The Finite Element Method ◽  
Classical Elasticity ◽  
Element Analysis ◽  
Plate Deformation ◽  
The Finite Element Analysis ◽  
Circular Holes ◽  
Different Shapes

This paper presents the numerical study of Cosserat elastic plate deformation based on the parametric theory of Cosserat plates, recently developed by the authors. The numerical results are obtained using the Finite Element Method used to solve the parametric system of 9 kinematic equations. We discuss the existence and uniqueness of the weak solution and the convergence of the proposed FEM. The Finite Element analysis of clamped Cosserat plates of different shapes under different loads is provided. We present the numerical validation of the proposed FEM by estimating the order of convergence, when comparing the main kinematic variables with an analytical solution. We also consider the numerical analysis of plates with circular holes. We show that the stress concentration factor around the hole is less than the classical value, and smaller holes exhibit less stress concentration as would be expected on the basis of the classical elasticity.

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