Fracture problems in composite materials

Erdoğan, F.

doi:10.1016/0013-7944(72)90018-5

Cited by 116 publications

(27 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…An up-to-day review of the general fracture problems in composite materials and a summary of some of the known results may be found in [7]. The distinguishing feature of the solutions given in [1][2][3][4][5][6][7] as well as the other known solutions which appeared in literature within the past decade is that the strength of the stress singularity at the imperfection front is -1/2 and, in the case of a crack, the quasi-static stress state in the neighborhood of the crack front remains autonomous as the crack propagates. That is, aside from a slight change in a multiplicative constant known as the stress intensity factor, the asymptotic nature of the stress state in the vicinity of the crack front remains unchanged.…”

Section: Introductionmentioning

confidence: 99%

Two bonded half planes with a crack going through the interface

Erdoğan

Biricikoglu

1973

International Journal of Engineering Science

Self Cite

243

View full text Add to dashboard Cite

Type of Report and Period CoveredContractor Report 14. Sponsoring Agency Code Supplementary Notes AbstractThe plane problem of two bonded elastic half planes containing a finite crack perpendicular to and going through the interface is considered. The problem is formulated as a system of singular integral equations with generalized Cauchy kernels. Even though the system has three irregular points, it is shown that the unknown functions are algebraically related at the irregular point on the interface and the integral equations can be solved by a method developed previously. The system of integral equations is shown to yield the same characteristic equation as that for two bonded quarter planes in the general case of the through crack, and the characteristic equation for a crack tip terminating at the interface in the special case.The numerical results given in the paper include the stress intensity factors at the crack tips, the normal and shear components of the stress intensity factors at the singular point on the interface, and the crack surface displacements. The plane problem of two bonded elastic half planes containing a finite crack perpendicular to and going through the interface is considered. The problem is formulated as a system of singular integral equations with generalized Cauchy kernels. Even though the system has three irregular points, it is shown that the unknown functions are algebraically related at the irregular point on the interface and the integral equations can be solved by a method developed previously. The system of integral equations is shown to yield the same characteristic equation as that for two bonded quarter planes in the general case of the through crack, and the characteristic equation for a crack tip terminating at the interface in the special case. The numerical results given in the paper include the stress intensity factors at the crack tips, the normal and shear components of the stress intensity factors at the singular point on the interface, and the crack surface displacements.

show abstract

Section: Introductionmentioning

confidence: 99%

Two bonded half planes with a crack going through the interface

Erdoğan

Biricikoglu

1973

International Journal of Engineering Science

Self Cite

243

View full text Add to dashboard Cite

show abstract

“…First, referring to the results given in [13] with regard to the stress singularities in bonded wedges of two dissimilar elastic materials one may observe that if the adherends and the adhesive are treated as elastic continua then generally the interface stresses cr and T would have a power singularity at the end points ;l. On the other hand, if the adherends are treated as elastic continua and the adhesive is assumed to be an uncoupled tension-shear spring, then the kernels of the related integral equations would have only logarithmic singularities and consequently the stresses cr and T would be bounded everywhere, including the ends. Furthermore, the examples given in [10] and [11] show that in this case the maximum stresses are at the end points. In this sense, the condition that the (*}For some joint geometries, significant differences were observed between the two sets of calculated results.…”

Section: Discussion and The Finite Element Solutionmentioning

confidence: 99%

“…The primar,y factors influencing the choice of a particular idealized model for the adhesive and the adherends appear to be the adhesive-to-adherend and adherend-to-adherend thickness ratios and the ratio of the adherend thickness to the lateral joint dimensions. Thus, in [1,2] the adhesive is neglected and the adherends are treated as membranes, in [3,4] it is assumed that the adherends are membranes and the adhesive is a shear spring, in [5][6][7][8] the adherends are assumed to be plates and the adhesive a tension-shear spring, and in [9][10][11] one or both adherends are treated as an elastic continuum. One should, of course, add that by using the finite element method, it is possible to treat all three components of the adhesively bonded structure as elastic continua.…”

Section: Introductionmentioning

confidence: 99%

Stresses in adhesively bonded joints: a closed-form solution

1982

Composites

View full text Add to dashboard Cite

In this paper the general plane strain problem of adhesively bonded structures which consist of two different orthotropic adherends ;s considered. Assuming that the thicknesses of the adherends are constant and are small in relation to the lateral dimensions of the bonded region, the adherends are treated as plates. Also, assuming that the thickness of the adhesive is small compared to that of the adherends, the thickness variation of the stresses in the adhesive layer is neglected. However, the transverse shear effects in the adherends and the in-plane normal strain in the adhesive are taken into account. The problem is reduced to a system of differential equations for the adhesive stresses which is solved ;n closed form. A single lap joint and a stiffened plate under various loading conditions are considered as examples. To verify the basic trend of the solutions obtained from the plate theory and to give some idea about the validity of the plate assumption itself, a sample problem is solved by using the finite element method and by treating the adherends and the adhesive as elastic continua. It is found that the plate theory used in the analysis not only predicts the correct trend for the adhesive stresses but also gives rather surprisingly accurate results. The solution is obtained by assuming linear stress-strain relations for the adhesive. In the Appendix the problem is formulated by using a nonlinear material for the adhesive and by following two different approaches.

show abstract

“…The existing analytical studies are, therefore, based on certain simplifying assumptions with regard to the modeling of the adhesive and the adherends. The adherends are usually modeled as an isotropic or orthotropic membrane (e.g., ['1]), plate (e.g., [2, '3]), or elastic continuum (e.g., [4,5]). The primary physical consideration, used in the selection of a particular model is generally the ratio of the thickness of the adherend to the lateral dimensions of bond region'.…”

Section: Introductionmentioning

confidence: 99%

Viscoelastic Analysis of Adhesively Bonded Joints

Delale

Erdoğan

1981

Journal of Applied Mechanics

Self Cite

View full text Add to dashboard Cite

In this paper an adhesively bonded lap joint is analyzed by assuming that the adherends are elastic and the adhesive is linearly viscoelastic. After formulating the general problem a specific example for two identical adherends bonded through a three parameter viscoelastic solid adhesive is considered. The standard Laplace transform technique is used to solve the problem. The stress distribution in the adhesive layer is calculated for three different external loads namely, membrane loading, bending, and transverse shear loading. The results indicate that the peak value of the normal stress in the adhesive is not only consistently higher than the corresponding shear stress but also decays slower.

show abstract

Fracture problems in composite materials

Cited by 116 publications

References 21 publications

Two bonded half planes with a crack going through the interface

Two bonded half planes with a crack going through the interface

Stresses in adhesively bonded joints: a closed-form solution

Viscoelastic Analysis of Adhesively Bonded Joints

Contact Info

Product

Resources

About