Hysteretic behavior of completely overlap tubular joints

The completely overlap joints used in an eccentric offshore jacket were inv estigated by both the experimental method and finite element analysis. A fu ll scale specimen was tested under cyclic quasi-static loadings to understa nd its performance under seismic loading. In the test, local buckling was f irst observed at the through brace in the intersection area. Then, a crack was found in the weld toe between the lap brace and the through brace. The propagation of the crack led to final failure of the joint. Some indicators to assess the performance of the joint were evaluated within the context o f seismic resistance. The energy analysis indicated that the local buckling at the intersection area was the main energy dissipating mechanism. Compar ison with an N-joint shows that the completely overlap joint performed bett er under seismic loadings. After calibration by the experimental results, a n extensive finite element analysis was carried out to determine the main f actors that have significant influence on the hysteresis behavior of the jo int. (C) 2001 Elsevier Science Ltd. All rights reserved.