Research On The Regulation And Standardization Of Impact Environment For Large Floating Shock Platform

The good anti-shock performance of shipborne equipment is of great significance to the safety of warships.As an important test system for the anti-shock research of shipborne equipment,it’s necessary to analyze the impact dynamic characteristics of the Large Floating Shock Platform(LFSP)and master its assessment ability.At present,in view of the limited structure form and examination range of the platform,considering design an auxiliary structure of underwater appendage to adjust the impact environment of the platform,and change the large horizontal-vertical difference of the traditional platform.This thesis established a corresponding numerical model,discussed the function of underwater appendage by means of ship test and numerical simulation,which verified the impact similarity between simulation and test,this would help perfects the related research and system construction of LFSP.In order to meet the requirements of test and engineering,it’s necessary to investigate the processing method of the impact environment and use the data to discuss the predication of impact environment.Against this background,the impact environment characteristics of LFSP and its impact environment regulation are studied in this thesis,which may give a reference for our construction of platform test system.The details are as follows:First of all,according to the anti-shock requirements of GJB1060.1-91 to equipment,the impact dynamic design values of surface ship and cylindrical shell are compared to understand the difference of equipment in different installation positions of ship.The impact response characteristics of the LFSP is investigated,which help to acquaint the gap between the assessment ability of the test system and the requirements of criterion.In order to reduce the difference of horizontal-vertical impact strength of platform,an underwater appendage auxiliary structure is used to adjust the impact environment of FSP,and the theoretical analysis of underwater appendage illustrate the feasibility of underwater appendage structure design.Secondly,the measurement methods of structural response in impact experiment are explained,and the Empirical Mode Decomposition(EMD)method is considered to deal with the zero drift problem of shock response signal,so as to prepare for the data processing of ship test.In order to understand the components and sources of the low frequency response,the low frequency inherent characteristics of the platform are analyzed,which provide an effective data support for the zero drift filter of EMD.In addition,the displacement response characteristics of the platform are analyzed by the low frequency oscillator.Finally,considering the complex input-output relation of the platform subjected to UNDEX,the spherical shock factor is used to describe the impact strength of the platform.the effect of underwater appendage is verified by numerical simulations and real ship tests,and the accuracy of the numerical simulation also be illustrated.After that,the coherence between shock factor and impact response is analyzed by combining the front results.the thesis take the influence of various factors to the impact environment of the platform into account in UNDEX by the numerical model and simulation results,and the non-linear relationship between input parameters and output response in UNDEX is effectively transformed into a linear relation by using the shock factor of corresponding condition.