Offshore platforms are always subjected to wave action which is random variable amplitude cyclic loading. In order to simulate the stressing condition at the 'hot spot' of the tubular joints and the marine env...Offshore platforms are always subjected to wave action which is random variable amplitude cyclic loading. In order to simulate the stressing condition at the 'hot spot' of the tubular joints and the marine environment, random variable amplitude fatigue tests have been carried out on welded plate joints in sea water. The tests have been conducted under the conditions of loading frequency of 0.2 Hz/, stress ratio of -1, seawater temperature of about 20°C and cathodic protection with the potential about -850 mV, SCE. The test results have been compared with the seawater corrosion fatigue life under constant amplitude loading. Miner's linear cumulative damage summation rule has been used to predict the corrosion fatigue life under variable amplitude loading. The predicted life is in good agreement with the test data.展开更多
Bending fatigue tests were carried out on cruciform welded joints of China-made platform steel E36-Z35 with plate thickness of 16mm, 32mm and 40mm. The tests consisted of testing in air and in sea water with and witho...Bending fatigue tests were carried out on cruciform welded joints of China-made platform steel E36-Z35 with plate thickness of 16mm, 32mm and 40mm. The tests consisted of testing in air and in sea water with and without cathodic protection (-850mV. SCE). The sea water corrosion fatigue tests were conducted at loading frequency of 0.2 Hz and sea water temperature of 20°C. The test results show an obvious reduction in fatigue strength of welded joints with increasing plate thickness in all the three test conditions. The present paper proposes different thickness corrections for fatigue strength and fatigue life of welded joints in air and in sea water with and without cathodic protection respectively. In addition, an explanation for thickness effect on fatigue life of welded joints is given by using the theory of fracture mechanics.展开更多
文摘Offshore platforms are always subjected to wave action which is random variable amplitude cyclic loading. In order to simulate the stressing condition at the 'hot spot' of the tubular joints and the marine environment, random variable amplitude fatigue tests have been carried out on welded plate joints in sea water. The tests have been conducted under the conditions of loading frequency of 0.2 Hz/, stress ratio of -1, seawater temperature of about 20°C and cathodic protection with the potential about -850 mV, SCE. The test results have been compared with the seawater corrosion fatigue life under constant amplitude loading. Miner's linear cumulative damage summation rule has been used to predict the corrosion fatigue life under variable amplitude loading. The predicted life is in good agreement with the test data.
文摘Bending fatigue tests were carried out on cruciform welded joints of China-made platform steel E36-Z35 with plate thickness of 16mm, 32mm and 40mm. The tests consisted of testing in air and in sea water with and without cathodic protection (-850mV. SCE). The sea water corrosion fatigue tests were conducted at loading frequency of 0.2 Hz and sea water temperature of 20°C. The test results show an obvious reduction in fatigue strength of welded joints with increasing plate thickness in all the three test conditions. The present paper proposes different thickness corrections for fatigue strength and fatigue life of welded joints in air and in sea water with and without cathodic protection respectively. In addition, an explanation for thickness effect on fatigue life of welded joints is given by using the theory of fracture mechanics.
