| With the continuous improvement of China's industrialization process,the rapid development of the automobile industry has brought convenience to people.At the same time,the occurrence of traffic accidents has brought great threat to the safety of human life and property,which has brought great negative impact to China's economy.How to improve the safety of car collisions has become an important research topic to protect people's safety.Europe and the United States are the first countries to start car collision safety testing.Their collision safety regulations are also the most widely used regulatory system in the world.Automobile safety test collision dummy,as the main testing equipment for passive safety of automobiles,is of great significance for the investigation of vehicle safety and the investigation of occupant damage.The Hybrid III 50 th dummy(The 50 th percentile means that the human body is of medium build)designed and manufactured by the United States is also the most widely used frontal collision detection device in the world and it is also the most representative of Western human characteristics.The collision dummy currently used in China is also the Hybrid III collision dummy or the dummy based on the Hybrid III collision dummy.Hybrid III dummy is designed according to the size of Western Americans,but the size difference between Chinese and foreign human body is large.Therefore,the damage results obtained by this series of dummy tests can not fully reflect the characteristics of human injury in China.With the development of computer technology,finite element dummy has also emerged.The finite element method is used to establish the dummy model,which makes up for the defects of the physical dummy's long production cycle,high cost and easy damage.It can also provide guidance for the development of physical dummy and become an important means in the development of the dummy.The use of finite element technology to study Chinese human body signs and collision dummy has important guiding significance for the development of domestic physical dummy.In a frontal collision accident,the probability of head injury is greater,and it is also the most frequently injured part.The proportion of neck injuries has exceeded 50% in all crashes,especially in frontal and rear-end collisions.The incidence of chest injury is second only to brain injury,which is up to 45%.The high incidence of injury to the upper torso is an important cause of death and disability of the occupants.Therefore,based on the cooperation development project between the author's research group and an automobile research institute in China,this paper is devoted to designing a Chinese physique finite element dummy.Then based on the vehicle restraint system of a certain model in China,this paper will also explore the response and injury characteristics of Chinese physique dummy's upper torso.The main research has the following contents.The author analyzes the research status of human injury caused by domestic traffic accidents and the research status of automobile collision dummy.By studying and studying the mechanical properties of human biological damage and safety regulations,the tolerance limit of the main injured part of the human upper body was confirmed.The summary of the main injury status of the human body on the trunk and the reading and analysis of the relevant evaluation criteria of the C-NCAP regulations provide theoretical support for the establishment of the Chinese 50 th percentile dummy.Based on the human body physiology measurement data,human anatomy,physical dummy and mathematical model,according to the human body structure,the three main injured parts of the head,neck and chest in the upper torso of the dummy are equivalently modeled.Other parts are also simplified in modeling according to the human body structure.The dummy model contains the movement and damping characteristics of the human bones,muscles,and major joints and major joints.Then the completed model is meshed to generate a finite element model,which is given the material properties,and the model parts are connected and contacted.The Chinese 50 th percentile dummy model is integrated.Comparing the human body signs between China and foreign countries,the main differences between Chinese and foreign human body signs are revealed.Based on the differences in human body signs between China and foreign countries,the Chinese and foreign dummies will establish a binding relationship with the vehicle system and conduct a frontal collision test.By simulating the dynamic results and various output indicators,the response and damage differences between Chinese and foreign dummy under normal working conditions are compared.The results show that in the same collision simulation test,compared with the Hybrid III dummy,the Chinese dummy model established in this paper is smaller and its riding position is more advanced.As a result,the change of the position of the dummy causes the peak of the synthetic acceleration of the head to decrease,and the risk of injury is reduced.Although the values of the various damage indicators of the neck are reduced,the contact time of the head,the chest and the airbag changes due to the higher position of the Chinese dummy.It causes changes in the state of neck movement,and increases the risk of injury from the motion response;the chest compression index decreases,and the risk of injury decreases,but it is not much different from the Hybrid III dummy.According to the differences in driving habits and sitting postures of different occupants while driving,the standard sitting posture of Chinese dummies is adjusted,and six representative sitting postures are set.The crash test is carried out under the same conditions.A comparative analysis of the damage changes of the upper torso of Chinese dummy shows that: The change of the vertical distance of the Chinese dummy relative restraint system has little effect on the damage of the dummy's upper trunk.But the change of the distance between the dummy and the steering wheel will directly affect the damage situation,especially the forward and backward tilt of the dummy's upper torso,which is more than the damage caused by the dummy's translation.During the collision test,it is necessary to improve the protection ability of the restraint system to the dummy.In order to evaluate car safety,Considering the influence of sitting posture on the response and injury status of the dummy,it is also necessary to consider the motion relationship between the various parts of the dummy in each sitting position and the potential damage risk due to the motion response,rather than through a single indicator or a single position. |
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