Interface crack initiation at V-notches along adhesive bonding in weakly bonded polymers subjected to mixed-mode loading

Abstract

In this paper, interface crack initiation at V-notches along adhesive in bonded Polycarbonate (PC) and Poly Methyl Methacrylate (PMMA) subjected to mixed-mode loading conditions was investigated based on a combined experimental, finite element and matched asymptotic analysis. The V-notch specimens with an adhesive interface starting from its tip made at different notch angles were tested under threepoint bending conditions. The experimental observations show that the specimens mainly fail by cracks along the interface. Also, the load at the crack initiation increases when the notch angle increases. The computational results are then used to explain and to correlate with the experimental data. A two-fold criterion developed by Leguillon (Eur J Mech A/Solids 21:61-72 2002) that requires a simultaneous satisfaction of both Griffith energy and stress conditions for the crack initiation at a notch in the specimen made of a homogeneous brittle material is first extended for

Dual-Notch Void Model to Explain the Anisotropic Strengths of 3D Printed Polymers

“…As a result, material properties at the interface are different from those of the bulk materials. Indeed, the authors developed a failure mechanics model to analyze crack initiation of a notch which is connected to an interface [21]. Application of this model to 3D printed polymers would be our future research.…”

“…The effect of the notch angles on the material strengths was extensively studied by the authors and other researchers [15][16][17][18][19][20][21]. Carpinteri found that the measured strengths of Polymethyl Methacrylate (PMMA) beams with different notch angles were an increasing function of the notch angles as shown in Figure 2 [20].…”

“…Moreover, it must be pointed out, that the CC coincides with the well-known Griffith's criterion in case of a pre-existing crack (ω = 0°), and with the maximum sustainable tensile stress for a plain (straight-edge) specimen without a notch (ω = 180°). The CC can be implemented using a full finite element procedure, by computing (1) and (4) for various virtual crack length l. There is also an asymptotic approach based on Williams' expansion of an elastic solution in the vicinity of a notch, we refer to [17,21] for a detailed presentation of this quasi-analytic approach. Results obtained by the asymptotic approach are shown in Figure 2 for double-edge-notched specimens of ABS (E = 2 GPa, ν = 0.25, KIc = 2.7 MPa m 1/2 , σc = 46 MPa of raw ABS) and PMMA (E = 2.5 GPa, ν = 0.25, KIc = 0.97 MPa m 1/2 , σc = 70 MPa of raw PMMA).…”

A review on failure theories and simulation models for adhesive joints

“…Tran et al [127] adopted a similar macro-scale approach to predict the failure load of PC/epoxy/PC and PMMA/epoxy/PMMA joints, thus quantifying the influence of the corner angle with good accuracy.…”

An experimental study on the crack initiation from notches connected to interfaces of bonded bi-materials

“…Yosibash et al [36] discussed a failure criterion for predicting failure in brittle materials subjected to mixed-mode loading. Recently, Leguillon extended his failure criterion to a general form for a notch as [28]:…”