The Research On Measuring Pressure Distribution On The Chest Of Crash Test Dummy

With the rapid development of automobile industry and economy,the number of cars in our country is increasing year by year,the car bring great convenience into people's life while causing a series of traffic accidents.According to statistics,the annual number of deaths due to traffic accidents in China is about 50 to 120 thousand,the number of injured is about 150 to 600 thousand.The incidence of thoracic injury in traffic accidents is very common,and the incidence rate of thoracic injury is only lower than that of head injury.And in the deaths caused by traffic accidents,the deaths caused by thoracic injury account for 30%.Thoracic injury mainly comes from the collision between the human chest and steering wheel,seat belts,vehicle interior and so on.So it has practical significance for improving the safety performance of vehicles and reducing traffic accidents in the thoracic injury to increase understanding the human chest pressure distribution during crash of the vehicle.At present,the domestic research on the thoracic injury is mainly focused on computer simulation analysis,and the study on the dummy chest pressure distribution is not carried out.The study on measuring pressure distribution is mainly focused on the field of medical biomechanics,and the pressure distribution measurement technique is not mature.In order to make up for the above deficiencies,this paper put forward a method of measuring crash dummy chest pressure distribution,and developed a crash dummy chest pressure distribution measurement system,the system parameters were analyzed by orthogonal test design,and it is verified that that the system can be applied to measure the dummy chest pressure distribution in the crash test.The main work and research contents of this paper are as follows:1.The method of measuring crash dummy chest pressure distribution was studied,and a set of crash dummy chest pressure distribution measurement system was developed.The pressure measuring principle of the Fuji prescale pressure-sensitive film was studied.The calibrating experimental bench was designed and the calibration test of pressure-sensitive film was carried out.The concentration of color results of the pressure-sensitive film were obtained under different pressure.2.The settings of the scanner were determined by analyzing the scanning results.The function of processing and displaying the results of the pressure-sensitive film was achieved by programming based on the image processing technology of MATLAB software.3.The influence of the three parameters of the measurement system on reading result was explored by orthogonal design.An optimal scheme for the parameter setting of the measurement system was obtained and the significance of those parameters were analyzed.4.The verification test of the measurement system was designed and carried out according to the regulation of the dummy thorax calibration test in low and high speed.Sled crash tests were done to apply the measurement system to measure dummy chest pressure distribution.The results suggests that the concentration of color results of pressure-sensitive film under different pressure is different,and greater pressure has higher concentration;The scanning results changes with different scanner's settings,so analyzing scanner's settings should do before scanning the results of pressure sensitive film;The crash test dummy chest pressure distribution measurement system which is based on MATLAB can visually display the measurement results of the pressure distribution;The hold time in the calibration test of pressure-sensitive film has significant impact on the measuring results,and the resolution of scanner and the level of filter have no significant impact on the measuring results;The crash test dummy chest pressure distribution measurement system can be applied to measure the dummy chest pressure distribution in the crash test.It can accurately calculate total forces and allow pressure to sightly exceed the full-scale value,but it has large error when the pressure on dummy chest is too large;In the crash test of passengers belt restraint system like the test in this paper,the scapula and ribs of dummy is main bearing components in dummy and the right of ribs bears much stronger stresses than the left of ribs.