| In recent years,with the increasing crimes of terrorist organizations in the international community,many countries have stricter management of firearms.However,tools such as knives have not yet been regulated,and the threat posed by the murderous way of committing crimes still exists.Through the analysis of the stab-resistant mechanism of stab-resistant clothing,the finite element method was used to establish the equivalent impact finite element simulation model of stab-resistant clothing and the impact finite element simulation model of human body wearing stab-resistant clothing.The human body stab-resistant equipment impact testing machine was designed,and the physical experiment of the stab-resistant material for impact and the stab-resistant impact physics experiment under the human body wearing state were used to verify the two impact finite element simulation models.Two simulation models were used to analyze the protective performance of stab-resistant clothing at different initial speeds.The conclusions of this paper were as follows:(1)Research and analysis the stab-resistant mechanism of stab-resistant clothing,including analyzing the force of stab-resistant clothing when the tool penetrates stab-resistant clothing at zero or at an angle of incidence.It was concluded that when the tool was pierced into the stab-resistant garment at a zero-degree incident angle or at an incident angle of less than 45 degrees,the upper anti-stinging layer had strong shear resistance.As the number of layers increased,strengthening the tensile properties of the stab resistant layer material was beneficial to improve the stab resistance of the stab resistant material.When the tool penetrates the stab-resistant clothing with an incident angle of more than 45 degrees,the surface of the stab-resistant material has strong tensile resistance.Enhancing the bottom shear resistance was beneficial to improve the stab resistance of the stab resistant material.(2)The stab-resistant armors for human body against mechanical impact tester was designed and developed.The impact tester can test the protective performance of a variety of stab-resistant materials,and stab-resistant clothing under the condition of worn.The device is capable of impacting stab-resistant garments at angles of 0 and 45 degrees.The test data includes the impact force and the acceleration versus time curves,and the ability to test the speed at which the impact tool contacts the stab-resistant garment.(3)The equivalent impact finite element simulation model of stab-resistant clothing was established,verified and applied.By analyzing the stab-resistant mechanism of stab-resistant clothing,an equivalent stab-resistant geometric model was established.By analyzing the construction principle of the equivalent finite element model of stab-resistant clothing,the constitutive model of the material and the failure criterion were determined.The load and boundary conditions,the type of meshing and the type of contact of the finite element model were determined according to the actual impact situation,the equivalent impact finite element simulation model of stab-resistant clothing was established finally.The equivalent impact finite element simulation model of stab-resistant clothing was verified by comparing the physical experiment results of stab-resistant materials.The results showed that the two experimental results have good consistency,and the equivalent impact finite element simulation model of stab-resistant clothing was effective.The equivalent impact finite element simulation model of stab-resistant clothing was used to analyze the protective performance of stab resistant materials at different initial speeds.(4)The impact finite element simulation model of the stab-resistant clothing worn by human body was established,verified and applied.The inverse modeling method was used to establish the geometric model of human body and stab-resistant clothing.According to different geometric models,two kinds of finite element software were used to divide the grid,and the advantages and disadvantages of the grid were compared.The boundary conditions,loads and interactions were created according to the actual situation,than the impact finite element simulation model of the stab-resistant clothing worn by human body was established finally.The human body stab-resistant equipment impact test machine was used to do the impact physical experiment of the stab-resistant clothing worn by human body,including the design and production of experimental stab-resistant clothing,experimental design and so on.Comparing and analyzing the results of physical experiment and simulation experiment,it was found that: due to the complexity of the impact finite element model of the stab-resistant clothing worn by human body,the experimental results were slightly different,but the matching results between the simulation results of the overall model and the physical experiment results have good consistency.The impact finite element simulation model of the stab-resistant clothing worn by human body was used to analyze the protective performance of stab-resistant clothing at different initial speeds.In this project,the method of establishing the impact finite element model can provide technical route and modeling ideas for the modeling method of functional clothing.At the same time,the equivalent impact finite element model of stab-resistant clothing and the impact finite element model of the stab-resistant clothing worn by human body can be applied to the stab-resistant performance verification analysis of various stab-resistant materials.There are 59 figures,14 tables,61 references in the paper. |
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