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Figure 7. Behavior of the king-post/tie-beam connection during 3F-C test.

-0.9 -0.8 -0.7 -0.6 -0.5 -0.4 -0.3 -0.2 -0.1 0.0 0.1 0.2 Relative displacement (mm)

Figure 8. Behavior of the left rafter/tie-beam connection during 3F-C test. Negative values are recorded when the two elements are approaching.

(a) Damage

Figure 9. Behavior of the left rafter/tie-beam connection during 3F-C test.

(a) Damage

(b) load-displacement curve of DG-7

Figure 10. Displacement recorded by LVDTs 1, 2 and 3 during 3F-N test.

-0.9 -0.8 -0.7 -0.6 -0.5 -0.4 -0.3 -0.2 -0.1 0.0 0.1 0.2 Relative displacement (mm)

Figure 8. Behavior of the left rafter/tie-beam connection during 3F-C test. Negative values are recorded when the two elements are approaching.

tie-beams, where a heel strap suspended the tie-beam, show different behaviors, Figure 8. Only the left connections, measured by DG-3, in the second series of tests (5F, 5 point loads), behave properly - the tie-beam is suspended to the queen post. In the first series of tests, both connections show plastic behaviour. Therefore, it can be concluded that, before the tests, those connections were dismantled. The first series of tests were sufficient for the left connections to recover, while the gap between both connected elements existing in the right connection was never recovered.

During the 3F-C test, significant damage was detected on the left rafter/tie-beam connection, over the DG-7, (Figure 9a). Damage started for a point load level of 700 kg and with 850 kg the measurement of the DG-7 only became stable after 30 minutes. At the end of the loading period, the maximum relative horizontal displacement between the rafter and the tie-beam (measured by DG-7) was reached and no recover was observed during and after the unloading procedure, Figure 9b.

Under non-symmetric loading, as the one imposed during the test 3F-N, distortion of the truss is observed,

Figure 9. Behavior of the left rafter/tie-beam connection during 3F-C test.

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