Failure Mechanism Analyses And Experimental Research On The Key Parts Of Large Anchor And Mooring Equipment

The shipping industry is a strategic industry which provides basic equipments for marine transportation and the ocean development, is also the essential industry foundation which is the safeguards of the national security, guarantees of the national energy strategy and the maintenance of the sea rights and interests. During "the 10th Five-Year Plan" of China, amazing achievements have been obtained in our shipping industry. "The 11th Five-Year Plan" of China is a crucial period for the development of ship-building industry. At present, the development of shipping supplementary equipment is still slow, which restricts the healthy development of our shipping industry seriously.Anchor and mooring handling equipment is one of the key deck machineries, which are vital for the safety of marine transportation. Its present design method is conservative and time consuming, so it is difficult to carry out comprehensive analysis. There are relative high difference between theoretical bearing capacity and actual bearing load. In order to satisfy the market demand on production cost, cycle and market rapid response, and enhance the competitive ability of products, it is necessary to carry out thorough theoretical analysis and experimental research on anchor and mooring handling equipment.The dissertation is supported by the research project on "Φ117 chain type anchor and mooring equipment analysis and test". To improve the present conservative design method for band brake and drum, heat transfer theory, modern mechanics, finite element theory and thin shell theory are employed. Systematic researches have been done based on modern experimental technology and CAE software. Main research conclusions are as follow:1) The basic friction theory of flexible body is used for force analysis of the band brake; its 3D-model is established by using SolidWorks. The mechanical stress fields under the rated condition and the lapse condition are analyzed by employing MSC.Patran/MSC.Marc; the interior stress distribution of the band brake is obtained; its limit load of strength failure has been determined. Also actual stresses of the band brake under the rated condition are measured by strain gauge. Result comparison shows the correctness of the FEA model.2) Based on the heat transfer theory, the mechanism of heat production for brake friction is analyzed; the 3D transient heat conduction mathematical model of band brake is established; with MSC.Patran/MSC.Marc, transient state temperature fields are acquired under the repetition braking condition and the emergency braking condition; the transient temperature distribution on the friction band and the steel band are obtained, some phenomenon and results are shown.3) Using the non-linear elementary theory and combining the contact algorithm with the multi-fields coupling principle, the thermal-mechanical stress coupling of the band brake uses has been analyzed under the normal condition with MSC.Patran/MSC.Marc; the temperature field and coupling stress field are revealed for the braking process, the mechanism of strength failure for connecting bolts are discussed.4) With the SolidWorks, the 3D-model of the drum is established; its mechanical stress field analyses are carried out under the rated condition (three different loads) and the collapse condition; the maximum load of strength failure for the drum has been determined; Stresses of the band brake under the rated condition are measured by strain gauge; by comparing the simulating results and the experimental results, the pressure distribution on the drum is determined; the correctness of the FEA model is verified.5) On the basis of thin shell theory and elastic mechanics, the drum stability computational method is analyzed; the corresponding theoretical formula is derived. Then the buckling analysis of the drum has been done by using MSC.Patran/ MSC.Marc. It is found that the traditional calculation method is too conservative. Finally the stable failure mechanism analysis is carried out for the drum; thus the limit load of destruction is given.