Design And Simulation Verification Of Frontal Crash Dummy Chest With Adjustable Posture And Three-dimensional Displacement Measurement

Entering the second decade of the 21 st century,Chinese car ownership is exploding every year,traffic accidents like the accompanying products,often happen around us.Therefore,the automobile safety problem is more and more valued by people.Dummy,a kind of test equipment which can be used to detect the damage of occupant in the course of vehicle collision,is playing an important role both in the development of automobile and in the follow-up evaluation of the safety performance of the vehicles.With the gradual maturation of automobile active safety technology,the AEB test is gradually incorporated into the new car assessment program by many countries.However,some studies have shown that,under the vehicle autonomous emergency braking,the occupant will appear the phenomenon of forward tilting or turning.But the existing Hybrid III 50 th dummy's sitting posture is fixed and cannot satisfy the measurement of human body damage.Therefore,it is of great strategic significance and application prospect to design a new kind of chest structure that can adjust the posture and use laser displacement sensor to realize the three-dimensional measurement of chest displacement.Based on the Hybrid III 50 th dummy,this paper aims to improve and design a new chest structure,which satisfies the existing high speed calibration test index of chest,with the function of pre-adjustment for the posture of the thoracic spine(used to match the posture of the occupant in the AEB test).At the same time,three-dimensional displacement measuring mechanism is developed.The research work of this paper is divided into the following three parts:(1)Based on the study of the collision law and the development trend of the dummy,and referring to the anatomical structure of the rib,and in the case of fully understanding the mechanism of thoracic injury,this paper improves the thoracic structure of the existing Hybrid III 50 th dummy and redesigns thoracic spine,displacement measuring mechanism and ribs by using laser displacement sensor,and establishes a new three-dimensional model and its corresponding finite element model.(2)According to the procedure of chest high speed calibration,the calibration test and the simulation calibration test are performed on the Hybrid III 50 th dummy and the finite element dummy with the chest model established in this paper,The structural parameters of rib are optimized by a series of optimization design methods,and the validity of the model is validated finally.(3)Based on a sled test of one vehicle,this paper verifies the validity of the chest model in the automobile restraint system,which has passed the chest high calibration test.The sled simulation test is carried out by building the working condition consistent with the real sled test.Comparing the chest acceleration curve and the chest displacement curve obtained by the simulation test and the real test,it also shows that the chest model has a certain rationality in the restraint system..