Study On Monitoring Method Of Internal Strain And Temperature Characteristics Of Cast Explosives Based On Optical Fiber Sensors

There are many state changes in the process of explosive casting and forming,among which strain and temperature are the most important parameters,and state changes will affect the quality and performance of explosives.In addition,in the process of explosive storage,safe monitoring methods are also required to prevent explosions and other accidents.Compared with the traditional electrical measurement method,the optical fiber sensors with the advantages of high insulation,strong anti-interference ability,small size,reasonable lowest cost,and can be embedded into its interior for remote monitoring without affecting the explosive structure.In view of the characteristics and monitoring requirements of the inflammable and explosive casting explosives,this paper prepared two types of optical fiber sensors as real-time monitoring scheme,and designed and built the explosive monitoring system,which provides a scientific and effective method for monitoring the change of the characteristics of the explosive casting process,as well as analyzing the long-term stability and failure detection of explosives.In this paper,two kinds of fiber Fabry-Perot(F-P)sensor structures were prepared by using chemical etching,discharge welding technology and precision cutting technology.They are single-mode and multi-mode fiber single-end microbubble structures and single-mode fiber and glass tube axially symmetric structures.Polydimethylsiloxane(PDMS)mixture was used to package the sensor,and carries on the strain/temperature sensitivity testing,through the testing of the sensitivity analysis,comparison of the two kinds of F-P sensor performance,the final choice for single mode fiber and glass tube material of axisymmetric structure paraffin simulation experiment,through interference spectrum peak tracking method to analysis the internal temperature of the paraffin and the regularity of strain.This article also according to the different need of strain and temperature measurement on naked grating reasonable packaging made from Fiber Bragg Grating(FBG)sensor,the encapsulated FBG sensor calibration analysis its validity,and paraffin structure simulation experiments are carried out using FBG sensors and cast explosive forming and internalstrain/temperature real-time monitor of the stored procedure experiment,analyzes the casting process of explosive forming and storing temperature,strain rule,the experimental results show that the low temperature stage of strain and temperature exist certain linear relationship,but also proved that the optical fiber sensor used in casting explosives inside the feasibility and reliability of the measurement.