Large-Scale Component Tests

Building on the standardized adhesive tests described in the section “Determination of Mechanical Values of the Adhesives" and the small-scale push – out tests discussed in the section “Small-Scale Component Tests," the bearing behavior was studied via large-scale component tests. As the effectiveness of the load transfer through the adhesive connection mainly depends on the length of the hybrid beam, a span of 4 m was chosen for constructional aspects. Figure 6 shows the test setup of the four point bending test. Within the test series, the cross-sectional dimensions were kept constant, and only the adhesive varied, using the adhesives K01, K05, and K07 from Table 2. The hybrid beams were dis­placement controlled loaded until glass breakage, and it became obvious that the carrying capacity significantly rises with increasing shear stiffness of the adhesive (see Fig. 7). The calculation of stresses at midspan shows that the different bearing

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Large-Scale Component Tests

Подпись: FIG. 6—Test setup of large-scale tests.

Large-Scale Component Tests

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Large-Scale Component Tests

FIG. 7—Failure loads of large-scale tests.

capacities are directly related to the normal forces in the flanges, as moments in web and flanges are almost similar.

The large-scale tests were recalculated using analytical and numerical methods (see the section “Modeling and Design"), assuming a linear deflection behavior of the adhesive connection. These linear approaches are in good ac­cordance with the tests. Figure 8 compares the linear shear stiffness of the large-scale tests with the stiffness of the block shear tests (see the section “Determination of Mechanical Values of the Adhesives"). The shear stiffnesses of tests TS4 and TS5 match the secant stiffness of the associated block shear tests very well; the rather small discrepancy in TS1 is the result of a discovered inferior bonding quality of the component test.