Research On The Distribution And Velocity Of Explosive Fragments Based On Comb-shaped Target

In the process of development and acceptance of fragmentation warheads,the distribution and flight speed of explosive fragments are the key reference quantities to measure the lethality of warheads.It has important reference value for improving program design,weapon acceptance,and enhancing lethality.At present,most of the fragment damage testing methods used in China are the methods of erecting copper wire mesh targets,steel targets and paper targets.These methods have great obstacles to fragments.After the experiment,it is necessary to manually count the distribution of fragments on the target plate.error.Therefore,it is necessary to study the distribution and velocity of explosive fragments based on comb-shaped targets.In this paper,a fragment distribution and velocity measurement system based on a comb-shaped target is designed.By connecting two flexible coded comb-shaped targets to the data acquisition and storage module,the distribution position of fragments on the target plate and the speed of fragments passing through the target are measured.Measurement,after the test is over,communicate with the host computer to read the stored data.The operation principle and realized functions of the test system are comprehensively expounded,including the theory and overall design of the test of fragment distribution and speed.According to the working principle and scheme design of the system,the whole system can be divided into three parts: the coding comb target module,the data acquisition and storage module and the host computer.The function,logic and power supply module of the coding comb target module are designed in detail by using the coding comb targets in the X and Y directions as the trigger input of the signal.Taking FPGA as the main control module,the function design of the FPGA in the data acquisition and storage module is carried out.The modular design method and the top-down design idea are adopted.According to its functions,it is divided into four parts: phase-locked loop module,timing module,FIFO module design and UART module design,after the design is completed,use timing simulation to verify.At the same time,the three-dimensional dynamic distribution and velocity of the fragments are analyzed by numerical simulation method,and the error analysis of the initial velocity value of the simulation and the initial velocity of Gurney formula is carried out;and then the deviation of the fragment velocity detection by the comb-shaped target is corrected by the method of numerical simulation.Compared with the simulation results,the corrected model error is reduced by about 0.2%.Finally,the system is tested,including time test based on FPGA,distribution test based on comb-shaped target,overall test of fragment distribution and velocity test system based on comb-shaped target,and simulation calculation of fragment distribution characteristics.In general,the system can realize three-channel test,which verifies the accuracy of the system position distribution measurement,and the system time measurement resolution is ±10ns,which has certain engineering practical value.