Design Of Shock Wave Measurement System For Explosion In Free Field

The shock wave of explosion is an important part of the characterization of damage effect for weapons and ammunition.Measuring the parameters accurately such as overpressure,the duration of positive pressure and specific impulse is significant for evaluating the destruction of conventional weapons.At present,shock wave measurement usually divided into the ground overpressure test and free filed overpressure test.The process of the former is easy to environmental disturbance,leading to the test error of the ground overpressure measurement result and actual ammunition lethality assessment being large.However,free filed overpressure test means that there is no any barrier around or the test is completed in approximate without any effect condition,which can improve the accuracy.Therefore study on explosion shock wave test method of free-field appears to be particularly important.Given these points,storage test principle were applied in the system,including system structure,working principle,hardware and software design,data processing method and so on.Synchronization technique were also applied,making the independent systems being equipped with unified time benchmark and providing reliable foundation with data processing.Analyzing the advantages and disadvantages of different pressure transducer firstly,137 series transducer of PCB company are adopted,designing the appropriative circuit and making the error in the limit of 2%,improving the test precision drastically.Due to test environment is terrible,in order to improve the universality and reliability of the system,FPGA was applied to achieve integrated design of logic circuit,including primarily sequential control of AD converter,programmable control of sampling frequency,trigger controller and address generator.Not only data transmission,electrical management and control,but integrating time difference between the rising edge of pulse per second and trigger signalwere completed by MCU.Eventually,the compact design decreases the system volume and dissipation and the system for shock wave of free-filed has been tested in the static blast experiment,demonstrating the system can meet the design requirements and indicators of testing for shock wave,which had great practicability and prospect.