Application of the finite element method to prediction of onset of delamination growth

2002 ◽  
Vol 55 (2) ◽  
pp. 89-106 ◽  
Author(s):  
Antonio Miravete ◽  
Miguel A Jime´nez
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Study ◽  
Dissimilar Materials ◽  
3D Analysis ◽  
The Finite Element Method ◽  
Delamination Growth ◽  
Linear Elastic ◽  
Elastic Fracture ◽  
Element Method

The present article is concerned with the application of the finite element method to the analysis of the onset of delamination growth in composites by means of the virtual crack closure technique (VCCT). The article reviews first the application of linear elastic fracture mechanics (LEFM) to the analysis of delamination, as well as the reasons why the VCC technique is the standard method of combining LEFM and the finite element method to predict onset of delamination growth. The article also reviews the different solutions proposed in the literature to deal with the oscillatory singularity associated with a crack between two dissimilar materials (as is the case for a delamination) and the practical details of the VCCT application in a general 3D analysis. Finally, the results of a numerical study of the mixed mode bending (MMB) interlaminar fracture test are shown. The study applies the concepts reviewed along the rest of this article and presents some practical recommendations for the analysis of a delamination front using finite elements. This review article includes 77 references.

Update: Application of the Finite Element Method to Linear Elastic Fracture Mechanics

2010 ◽  
Vol 63 (2) ◽  
Author(s):  
Leslie Banks-Sills
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress Intensity ◽  
Stress Intensity Factors ◽  
Linear Elastic Fracture Mechanics ◽  
The Finite Element Method ◽  
Intensity Factors ◽  
Linear Elastic ◽  
Elastic Fracture ◽  
Element Method

Since the previous paper was written (Banks-Sills, 1991, “Application of the Finite Element Method to Linear Elastic Fracture Mechanics,” Appl. Mech. Rev., 44, pp. 447–461), much progress has been made in applying the finite element method to linear elastic fracture mechanics. In this paper, the problem of calculating stress intensity factors in two- and three-dimensional mixed mode problems will be considered for isotropic and anisotropic materials. The square-root singular stresses in the neighborhood of the crack tip will be modeled by quarter-point, square and collapsed, triangular elements for two-dimensional problems, respectively, and by brick and collapsed, prismatic elements in three dimensions. The stress intensity factors are obtained by means of the interaction energy or M-integral. Displacement extrapolation is employed as a check on the results. In addition, the problem of interface cracks between homogeneous, isotropic, and anisotropic materials is presented. The purpose of this paper is to present an accurate and efficient method for calculating stress intensity factors for mixed mode deformation. The equations presented here should aid workers in this field to carry out similar analyses, as well as to check their calculations with respect to the examples described.

Studies on the behaviour of screw piles by the finite element method

2009 ◽  
Vol 46 (6) ◽  
pp. 627-638 ◽  
Author(s):  
Nainan P. Kurian ◽  
Syed J. Shah
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
The Finite Element Method ◽  
Linear Elastic ◽  
Screw Pile ◽  
Geometrical Features ◽  
Helical Blade ◽  
Simplifying Assumptions ◽  
Actual Geometry ◽  
Element Method

A circular pile with helical blades is an old type of foundation, which has staged a comeback recently and is being used in a variety of situations. Most of the research on helical screw piles has been experimental or theoretical with the help of simplifying assumptions. The method of design adopted so far treats this pile as an annular plate, disregarding the intricacies of the geometry of the helix. It is only the versatility of the finite element method that can take into account the actual geometry of a spatial structure such as the helical blade at a microlevel. This is perhaps the first attempt at such an analysis to study the response of the helical screw pile within the elastic and nonlinear ranges. While the pile is linearly elastic, soil is considered both as a linear elastic medium and as an elastic–plastic medium following the Drucker–Prager constitutive model. Cases of smooth contact and frictional contact between soil and screw pile are also considered. Screw piles are studied under compressive, tensile, and lateral loading conditions. Moreover, their performance is compared with that of prismatic piles. A parametric study has also been attempted on some key geometrical features of the screw pile.

Analysis of Aerodynamic Journal Bearings With Small Number of Herringbone Grooves by Finite Element Method

1994 ◽  
Vol 116 (4) ◽  
pp. 698-704 ◽  
Author(s):  
D. Bonneau ◽  
J. Absi
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Study ◽  
Load Capacity ◽  
Journal Bearings ◽  
The Finite Element Method ◽  
Bearing Number ◽  
Comparison Of The Results ◽  
Herringbone Grooves ◽  
Element Method

A numerical study of gas herringbone grooved journal bearings is presented for small number of grooves. The compressible Reynolds equation is solved by use of the Finite Element Method. The nonlinearity of the discretized equations is treated with the Newton-Raphson procedure. A comparison of the results for a smooth bearing with previously published results is made and the domain of validity of the Narrow Groove Theory is analyzed. Load capacity, attitude angle, and stiffness coefficients are given for various configurations: groove angle and thickness of grooves, bearing number, and that for both smooth and grooved member rotating.

scholarly journals Applied mechanics of the Puricelli osteotomy: a linear elastic analysis with the finite element method

2007 ◽  
Vol 3 (1) ◽  
Author(s):  
Edela Puricelli ◽  
Jun Sérgio Ono Fonseca ◽  
Marcel Fasolo de Paris ◽  
Hervandil Sant'Anna
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Elastic Analysis ◽  
Applied Mechanics ◽  
The Finite Element Method ◽  
Linear Elastic ◽  
Element Method

An analytical approach to evaluate effective coefficients of 1–3 piezoelectric composites

2021 ◽  
Author(s):  
Sanjeev Kumar Singh ◽  
Saroja Kanta Panda
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Volume Fraction ◽  
Numerical Study ◽  
The Finite Element Method ◽  
Effective Coefficients ◽  
Square Packing ◽  
Packing Arrangement ◽  
Piezoelectric Fiber ◽  
Element Method

In this paper, a micromechanics method is developed to evaluate effective coefficients of piezoelectric fiber-reinforced composites. An exact solution is derived for effective elastic, piezoelectric and dielectric coefficients of such piezocomposites subjected to the applied load in the direction transverse to the fiber orientation. Simultaneously, based on finite element method, a numerical study is performed on a representative volume element of such piezo composite containing fiber in square packing arrangement. The finite element method provides a numerical solution to evaluate effective elastic, piezoelectric and dielectric coefficients for discrete volume fraction of fiber, the range being 0.1–0.6 for this study. The results are interpolated to understand the overall behavior of such piezocomposites. The results obtained from the micromechanics method and the finite element method are compared with the results obtained from other models based on strength of materials method given in the literature. It is observed that the method developed in this study provides better results for effective coefficients susceptible to fiber packing arrangements.

Application of the Finite Element Method to Linear Elastic Fracture Mechanics

1991 ◽  
Vol 44 (10) ◽  
pp. 447-461 ◽  
Author(s):  
Leslie Banks-Sills
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress Intensity ◽  
Fracture Mechanics ◽  
Displacement Field ◽  
Three Dimensional ◽  
Linear Elastic Fracture Mechanics ◽  
The Finite Element Method ◽  
Linear Elastic ◽  
Elastic Fracture

Use of the finite element method to treat two and three-dimensional linear elastic fracture mechanics problems is becoming common place. In general, the behavior of the displacement field in ordinary elements is at most quadratic or cubic, so that the stress field is at most linear or quadratic. On the other hand, the stresses in the neighborhood of a crack tip in a linear elastic material have been shown to be square root singular. Hence, the problem begins by properly modeling the stresses in the region adjacent to the crack tip with finite elements. To this end, quarter-point, singular, isoparametric elements may be employed; these will be discussed in detail. After that difficulty has been overcome, the stress intensity factor must be extracted from either the stress or displacement field or by an energy based method. Three methods are described here: displacement extrapolation, the stiffness derivative and the area and volume J-integrals. Special attention will be given to the virtual crack extension which is employed by the latter two methods. A methodology for calculating stress intensity factors in two and three-dimensional bodies will be recommended.

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