The Underwater Shock Mechanism And Optimization Design Of Layered Gradient Coating

Coating represents as the warships’ outstanding protective equipment,it plays an important role during the warship’s life.Traditional coating is made of rubber material,with many holes.Since the multihole rubber material is full of hyperelasticity and complexity,which may lead to the big computing data.Besides,engineers always use homogenous and stable material in the coating design,but there is still no improvement in shock resistant.This paper aims at the computing method and structural design,proposing a homogenization method,making the multihole coating simplified reasonably.Then,we design a Density Graded Polymer Foam coating(DGPF).It has some advantages such as little quality,small deformation,good energy absorption,which may be suitable for special underwater field.After some year’s research,the computing method and structural design gradually has become matured.With big warship’s structure,function,working condition has become more complicated,it calls further requirements of computing efficiency and protective function.This paper focus on proving the homogenization method can effective improve computing efficiency,DGPF has more advantages compared with traditional coating.This main research contents of this paper including:1)On the basis of common rubber coating model,we make parametric analysis of rubber coating,finding the main parameters which may affect coating’s function.Then make sure Yong’s modulus and Poisson’s ratio are the core of all parameters.On the basis of linearization method,we introduce the homogenization method.After getting the homogenization coating’s equivalent Poisson’s ratio,in view of practical application condition,we compute the coating 1 and coating 2 with real parameter values.From all aspects,proving the accuracy of homogenization method.2)Then we design Density Graded Polymer Foam coating(DGPF),adopting KNR theory,studying the shock resistant properties without fluid-structure coupling,comparing the results under different shock strength,decay factor,graded coefficient,and the cloud picture with shock strength and decay coefficient changes at the same time.Comparing these results with traditional homogenization coating at the same condition.Finally,we find out DGPF performs better in small parameter’s field.3)To further study DGPF’s shock resistant properties with fluid-structure coupling.On the condition of bottom fixed and bottom free,concluding the compression property under shock wave respectively.Through the comparisons among different cloud picture results,we get the conclusion that DGPF more suitable for far-field underwater explosion,performs better than traditional coating under big shock strength.