Analysis Of The Mechanism Of Excavation Resistance Of Special Shape Falling Object

There are few studies on the analysis of the resistance mechanism of submarine salvaged products at home and abroad.Especially with the rapid development of aerospace science and technology in recent years,aerospace devices have occasionally occurred on the seabed.This research gap has caused a great deal of difficulty to the salvage of aerospace devices.Based on the actual case,the aerospace device crashes into the seabed in a launch test,and is in urgent need of salvaging the device.However,there is a blind zone in the selection of the tonnage of the hoisting machine for the salvage operation and the setting of the uplifting load.In this context,this paper draws on previous theoretic research on the uplift piles and penetrating bombs by previous scholars,and makes a detailed analysis and calculation of the excavating mechanism of the research object in this paper.Including(1)Analyzes the influencing factors of the excavation resistance,including the three components: side friction resistance,earth pressure and adsorption force.The critical displacement is the characteristic of the relative displacement between the object and the soil when the side frictional resistance reaches the limit value.(2)The softening model of the tri-fold line side friction resistance is established for the anti-pulling characteristics of the study object,and the surrounding soil is deduced in different states.Analytical solution of the transfer of the lower load;(3)Analysis of the depth of the falling mud;(4)Simulation analysis of the object's unearthing process by finite difference software FLAC3 D,and the velocity and displacement curves of the object under different uplift loads;(5)Finally,the results of theoretical calculations were compared with those of the simulations,and the best salvage plan was obtained,a lifting load of 80 k N could be used to salvage the soil.However,the speed of excavation does not increase with the increase of the lifting load.The process of excavation of an object will follow the rule that the increase in load causes a certain degree of speed increase,leading to increased resistance to excavation.In order for the aerospace device not to be damaged in the salvage,or to break the anchor chain or damage the anchor,only a reasonable lifting load can be set.This provides a theoretical basis and simulation plan for similar incidents in which aerospace components fall into the sea and needs to be salvaged.This will bring undeniable assistance to the smooth development of the space industry.