But, existing rugs are designed based on the nominal stress using simple formulas developed in the time that structural analysis techniques are insufficient or FEM approach restricted within simple elastic structural analysis focused on the only lug structure, so that nowadays, more rational design approach is desired. DNV-OS-H205 Lifting Operation This standard provides specific guidance and recommendations for Engineered onshore, inshore and offshore lifting operations, conducted both in air and sub-sea. Because several lifting lugs per one block, are needed to be installed every time of block lifting, enormous quantity of lugs which are nearly amount to several hundreds of thousand unit, are fabricated and removed after completion of lifting. Finally large ships, that is, one of huge fabrication products are constructed. In order to construct them, after fabrication of unit panels and/or small blocks, many cranes transport enormous ship structure blocks which reach nearly from score to several hundred tons. Therefore, large shipyards which produces various steel ships nearly above 200 m, has production capability amount to one ship per a week respectively. Recently, korea has appeared top class of country in the field of shipbuilding industry due to the rapid development of economy and technology of naval architecture. Secondly optimum design studies are performed based on the practical design methods and general optimum design guides according to the variation of design parameters, are suggested. guidance related to the design of lifting devices including lifting lugs. Some analysis guides are suggested through the consideration of several important effects such as stress distribution pattern, circumferential contact force distribution along the Jug eye face, loading share rate between lug main plate and doubler, effect of loading direction, relation between applied force and deflection and size effect of shackle pin radius. lifting lug calculation material of lug yield stress width of lifting lug. Gap element modeling and nonlinear analysis procedures are illustrated and discussed based on MSC/NASTRAN. In order to establish the proper design & analysis guides, load distribution around lug eye, that is, investigation of contact force between lifting lug and shackle pin is performed using non-linear parametric analysis idealized by gap element models.
A basic study on the lifting lug design has performed through the rational and systematic process.