Study On Common Structure Rules And Relationship With Short-term Sea Condition Of The Oil Tanker's Ultimate Strength

With the rapid development of the global economy, the demand of the oil and its derivatives is increasing, and the deadweight of the tanker is also increasing, so the oil tanker being larger has been an inevitable trend. However, after the hull structure of being larger, if there is no sufficient longitudinal ultimate strength it will be most likely to cause fracture and the ship sank at sea. Therefore, study on the longitudinal ultimate strength of hull structure has a very important practical significance. Common Structure Rules for of Double-hull Oil Tankers taken effect at April 1st 2006, the first time, clearly pointed out the contents of calculation and check for the Ultimate Longitudinal Strength of the large double-hull tankers. At the same time, we can predict, although the design and the construction process strictly were satisfied with the requirements of the Rules, the ship in navigation can not fully avoid the risk of damage yet, and the damage, if the operation were not right, would be enlarged and result in more serious consequences.In this thesis, firstly the design concept and the mechanical connotation of longitudinal ultimate strength in the Common Structure Rules for Double-hull Oil Tankers were studied and analyzed and the conclusion of the progressive failure analysis method and reliability analysis methods have a realistic meaning to the design guidance of the oil tankers.And then, in order to study the relationship between the longitudinal ultimate strength and the short-term sea conditions, the equation of ship motion in regular waves was established with the original strip method, and the response of a 100,000 tons double-hull oil tanker's movement and amidships wave-induced vertical bending moment in the regular waves was got, and some conclusions were got too. With spectrum analysis method, amidships wave-induced vertical bending moment spectrums in irregular waves were got. The relationship between wave height, speed and longitudinal bending moment of short-term forecasting was got.Lastly, based on the longitudinal ultimate strength under a case of damage, the corresponding wave height and speed was got from the graphic of the relationship between wave height, speed and longitudinal bending moment of short-term forecasting, and the adjustment scheme of the route and the speed was made.