We have proposed economical design procedures of the mooring line.

The result of the computation for buoy mooring shows that the impulsive tension of the elastic chain is reduced up to 50% of that of the normal steel chain when a half of the mooring line is employed as the elastic chain and the other is as the normal chain. The validity of the model has been confirmed for the tension of the normal steel chain by the comparison with the experimental results by Hiraishi et al.(1995).

The model has adopted the lumped mass method for the simulation and can be applied for the normal and elastic chains. For the purpose of the cost reduction of mooring system, the authors have developed a simulation model to predict the motion of the mooring chain for a buoy and the impulsive tension acting on the chain. However, the cost of the elastic chain is quite high compared with that of the normal chain. The elastic chain for mooring can be expected to reduce the abrasion between the chain links and the intension of impulsive tension because of covered rubber material and its elasticity, respectively. The elastic chain is manufactured by burying steel chain links within rubber column. The authors have suggested to employ the 'Elastic Chain', which has the property of elasticity. The main causes of the breakage are the abrasion between the chain links and the large impulsive tension acting on the chain. However, the breakage of mooring chains has sometimes taken place. The coordinates are positioned as follows: the coordinate basic origin is combined with the impulse application point, the plane coincides with a nonperturbed ice - water interface, the axis Oz is directed vertically upward.ĪBSTRACT Steel chains are usually used for mooring of various structures such as marker buoys for navigation, pontoons, and ship mooring buoys. MATHEMATICAL STATEMENT Here we consider a floating infinite ice plate which at first is at rest in the state of equilibrium and is actuated in an instant t = 0 by a shock loading. The book Squire et al (1996) includes an extensive bibliography on a similar theme. Earlier Fox (1993) considered a similar problem without the account viscosity. The purpose of the present paper is to consider the linear axial symmetry task concerning the conduct of an ice cover after being affected by an instantaneous impulsive load. For estimation of this technology efficiency and also for its optimization both experimental and appropriate theoretical investigations are necessary. Nevertheless, this problem is of great economic value, as the breaking down an ice cover by explosion is used when constructing runways, to smooth out hummocks on the ice surface, to break down ice bonds and heavy hummocked ices when building shipping canals by ice-breakers, to expand of passageways between two ice caps and in their slivering, in squeezing ships by heavy ice, etc. impact impulses, is not sufficiently investigated. INTRODUCTION The conduct of ice under heavy loads originating in explosions, i.e. Analysis is made of the following factors: the effect of ice plate thickness, relaxation time, variable depth of a basin, remoteness and steepness of the bottom surface coast sloping and choice of a function type of an instantaneous impulsive load on the amplitude of the plate deflection. ABSTRACT: The paper deals with the linear axial symmetry task concerning the effect of an impulsive load on a viscoelastic ice plate superjacent the elastic basis, i.e.

Point impulsive force