Study On Classification Of A/C Group Of Marine Solid Bulk Cargo

Ships will be affected by wind and wave loads while sailing at sea.For bulk carriers,wind and wave loads will be transmitted to the cargo through the inner wall of the cargo hold.If the water content of the liquefiable solid bulk cargo is so high that the cargo may undergo fluidization.A free liquid surface is formed on the surface of the cargo,which reduced the stability of the ship and maked the ship overturn.Although the<International Maritime Solid Bulk Cargo Codes>gives a method to classify liquefiable solid bulk cargo,the method has some difficulties in actual operation.In order to give specific standards for the classification of liquefiable solid bulk cargo,selected four basic physical properties parameters of the cargo as the research object according to the current research situation.The four basic physical properties parameters are used as the basis for classification of liquefiable solid bulk cargo.According to the statistics of the data,the main ship types and sailing time of the main shipping areas in the world are determined.The complex ship motion was converted into uniaxial vibration motion through the calculation of ship motion load,and the load parameters of uniaxial vibration motion were calculated.Shaking table test was carried out on typical liquefiable solid bulk cargo,which verified that it was feasible to use FLAC 3D software to simulate the uniaxial vibration test of the shaking table.According to the principle of similarity,the similarity criterion studied in this paper was determined,and the physical quantity parameter in the actual transportation process was converted into the physical quantity parameter in the numerical simulation process through the similarity constant.Through a large number of numerical simulation tests,the four physical property parameter threshold ranges were determined,which were used as the basis for judging the A/C group of easy-to-flow solid bulk cargoes.The comparison of the four physical parameters of the classic cargo proved that the conclusions of this article can provide a basis for the classification of cargoes in the A/C group of liquefiable solid bulk cargo and provided quantitative classification criteria for the classification.