Single lap joints testing

Single lap joint test samples with thin (0.1 mm) and thick (1 mm) gluelines are subjected to ageing treatments before longitudinal tensile loading at a constant loading rate of (2.0 0.5 kN/min) up to failure (Eig. 2). 

Single- or double-lap joint test Basic metal-to-metal single lap joint test... 

Single-lap joint test for metal-to-metal joints at elevated temperatures... 

The lap joint test is the most commonly used adhesive test, likely because test specimens are simple to construct and resemble the geometry of many practical joints. While this test is commonly referred to as the lap shear test, this is generally a misnomer, since failure is often more closely related to the induced tensile stresses than to the shear stresses. Further, it is conventional to report the apparent adhesive strength as the load at failure divided by the area of overlap, even though the maximum stress will almost always differ markedly from this average value. Thus, while the lap joint test is commonly performed, the results from this test must be interpreted with caution. Issues associated with the single-lap joint test are discussed in ASTM D4896. 

The single lap joint test is the most widely used test method for durability studies. Its popularity lies in its relative simplicity and perceived ease of interpretation. This test method is sensitive to changes in adhesives and surface treatments in joint combinations. Small differences in joint conditions can give rise to variability. 

The standard single-lap joint test piece geometry has been analysed by Harris and Adams (1983) for aluminium adherends, and the various non-linearities included. With the material properties maintained as... 

Fig. 79. Single-lap joint test piece to ASTMD 1002-72 (1978) (dimensions...

The normalized nonlinear strength wearout model applied to aluminum-epoxy single lap joints tested at different loads (Shenoy et al. 2009b]... 

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