Research of Statistical Characteristics of Target Strength of a Single-layer Cylindrical Shell with Random Coating

2018 5th International Conference on Coastal and Ocean Engineering

Bo, Hu^1

China Ship Developing and Designing Centre, Wuhan, China^1

关键词: Analytical method;    Cumulative failure;    Cylindrical shell;    Dynamic characteristics;    Log-normal distribution;    Monte Carlo theory;    Statistical characteristics;    Statistical probability;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/171/1/012023/pdf
DOI  :  10.1088/1755-1315/171/1/012023

来源: IOP

【 摘 要 】

That anechoic tiles fall off from the surfaces is a common phenomenon that modern submarines are frequently faced with, which has negative effects on acoustic stealthy performance and increase Target Strength(TS) levels. Based on Monte-Carlo theory, PEM calculations are made by assuming that each anechoic tile fall off randomly and their conditions are tested separately. And the statistical-based values where statistical probability density of the PEM results reaches its culmination are considered as the TS level of a structure that part of its anechoic tiles fall off. The effectiveness of the MC-PEM is validated by the calculation of plate with anechoic tiles, since it achieves good agreement with the results of analytical method. And the relations between TS and the anechoic tiles' exfoliation rate of single-layer cylinder shell are gained by MC-PEM. Finally, log-normal distribution is introduced to describe cumulative failure probability of anechoic tiles. And the dynamic characteristic of TS versus non-dimensional time suggests that it is of significance to overhaul anechoic tiles in the region of 0.3t∼0.5t(t represents average lifespan of anechoic tiles) as to keep TS in relative low level.