Tapered double-cantilever beam

WTDCB width tapered double-cantilever-beam... 

ISO, Standard test method for mode I interlaminar fracture toughness, G/c, of unidirectional fibre-reinforced polymer matrix Composites. ISO 15024 2001. Blackman, B.R.K., H. Hadavinia, A.J. Kinloch, M. Paraschi and J.G, Williams, The calculation of adhesive fracture energies in mode I revisiting the tapered double cantilever beam (TDCB) test. Engineering Fracture Mechanics 2003. 70 p. 233-248. BSI, Determination of the mode I adhesive fracture energy, Gic, of structural adhesives using the double cantilever beam (DCB) and tapered double cantilever beam (TDCB) specimens. 2001. BS 7991. 

Substrates. Two commercial aluminium alloys (see Table 1), received as hot-rolled sheets (from ALCAN), were the main body-panel materials used in the current work. The thickness of the sheets varied from 1 to 3 mm for the 5754-0 alloy and from 1 to 2 mm for the 6111-T6 alloy. For the tapered double-cantilever beam (TDCB) tests, where the substrates should remain within the elastic region, a high yield strength alloy, 2014, was used throughout. The specimens were prepared and pre-treated prior to bonding using the procedures proposed by Blackman et. al. [2], The chemical compositions of the alloys employed are given in Table 1. 

Tapered Double Cantilever Beam (TDCB) Tests... 

This type of contoured specimen is known as the tapered-double-cantilever beam (TDCB) specimen. 

Standards such as the British Standards Institute BS 7991, Determination of Mode I Adhesive Fracture Energy, GIC, of Structural Adhesives Using The Double Cantilevered Beam (DCB) and Tapered Double Cantilevered Beam (TDCB) apply to these tests. 

In this chapter, an overview of performance characterization of FRP-wood bonded interfaces by conventional and fracture mechanics tests [4- 7] is presented. Modified ASTM standard tests (ASTM D2559 and D905) are first used to study the service performance and shear strength of the bond under moisture and/or mechanical loads, and then a contoured or tapered double cantilever beam specimen [8] is used to evaluate the fracture toughness of bonded interfaces under dry and wet conditions and cyclic loading. 

Finally, the tapered double cantilever beam specimen [8] described in this study can be effectively used to obtain interface mode-I fracture toughness values under various environmental loadings (e.g., under dry and wet conditions [5,14,15]) and cyclic load conditions (fatigue fracture [7]) these data can be implemented in practical applications to assess the potential growth of a delamination crack at the FRP wood interface. 

Determination of the mode I adhesive fracture energy, Gjc, of structural adhesives using the double cantilever beam (DCB) and tapered double cantilever beam (TDCB) specimens Essential work of fracture (EWF)... 

Brown, E.N. (2011) Use of the tapered double-cantilever beam geometry for fracture toughness measurements and its application to the quantification of self-healing. The Journal of Strain Analysis for Engineering Design, 46, 167-186. 

TDCB (tapered double-cantilever beam) specimens were used to determine the healing efficiency and repeatability of the healing. The specific geometry of the TDCB can be seen in Figure 7.27(a). The healing efficiency was evaluated by a tensile test using the Q-TEST 150... 

Tapered double cantilever beam (TDCB). The TDCB, or more accurately the contoured DCB, specimen as developed by Mostovoy... 

Fig. 4.14. Some adhesive joint fracture mechanics specimens, (a) Tapered double cantilever beam (TDCB). (b) Thick double cantilever beam (DCB). (c) Thin double cantilever beam or wedge cleavage specimen, (d) Independently loaded mixed-mode specimen (ILMMS). (e) Scarf joint.

Tapered double cantilever beam This is again mode I, but the value of dClda can be made constant by tapering of the arms of the specimen (see Fig. 2b). Thus, Gj is independent of crack length and this design is well suited to tests where the value of a is difficult to measure, for example, environmental tests (see Durability fundamentals) and dynamic fatigue tests. This is also used in ASTM D 3433. The value of Gic is given by... 

The interlaminar fracture toughness, in terms of strain energy release rate, has been determined by means of the Width Tapered Double Cantilever Beam (WTDCB) fracture specimen (8). In our case a thick aluminium WTDCB is adhesive-bonded to the thin laminates. 

The use of phenolic resins for wood bonding has been reviewed by Pizzi, Dinwoodie, Kollmann and coworkers, " the U.S. Department of Agriculture, and Barth. Tapered double cantilever beam specimens have been recently used to test the effect of bondline thickness and cure time on the fracture energy of phenolic-wood adhesive joints. ... 

Figure 26. The tapered double cantilever beam specimen.

FIGURE 13. Bonded tapered double cantilever beam (TDCB), used for quantitative evaluations of fracture toughness and environmental durability effects on bonded systems. (From Reference 25.)... 

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