Model Establishment And Dynamic Response Analysis Of Marine Evacuation Chute System

Marine evacuation chute system is mainly used in the field of marine life-saving,providing a safe and fast evacuation mode for personnel on offshore platforms and large ships.When the evacuation chute system works in the marine environment,it will be greatly shaken by the complex loads of the marine environment,which will affect the evacuation efficiency of personnel.In order to reduce the impact of large-scale swaying of marine evacuation chute system on evacuation efficiency under complex marine conditions and provide theoretical and data support for the follow-up design and research of marine evacuation chute system,the numerical model of the marine evacuation chute system is established and the dynamic response of the system is analyzed in this paper.Firstly,the overall scheme of the marine evacuation chute system is determined,and the distribution forms of the complex ocean environment loads are analyzed.The wind load,wave load and current load are described theoretically.According to the requirements of the International Life-Saving Appliances(LSA)Code,three sets of calculation conditions are determined for the subsequent analysis.Secondly,based on the multi-flexible segment model method,the theoretical model of the evacuation chute is deduced,and the motion and force characteristics of two different structures under the same wind load are compared,which provides a basis for the system to select the evacuation chute model with better environmental adaptability.Then,based on OrcaFlex,the numerical model of the marine evacuation chute system is established.The tension and evacuation chute response characteristics of the system under different calculation conditions,different weighting depth and different counterweight are analyzed.Finally,the influence of the motion response of the evacuation chute on the evacuation efficiency is discussed,and the key parameters of the chute are suggested.The results show that the motion of the evacuation chute system tends to be stable after a certain period of time under complex marine conditions.At this time,both the tension response of wire rope and the motion response of the evacuation chute show harmonic characteristics,which are in good agreement with the wave characteristics,and the amplitude of the response increases with the increase of marine conditions.The tension response of wire rope not only presents harmonic characteristics,but also accompanies with high frequency fluctuation characteristics.By analyzing the influence of different water entry depth and mass of counterweight on the tension and slideway motion response of the system,it is found that the water entry depth and mass of counterweight should not be too small or too large.When the depth of weighted water entry is 8 meters and the mass is about 400 kg,it is most suitable.With the decrease of the peak value of the chute motion response,the value range of the design inclination of the chute’s inclined net surface increases gradually.This paper is of great practical engineering significance to the design and research of the marine evacuation chute system.