Study On Energy Absorption Characteristics Of Carbon Nano Polyurethane Foam And Application In Autobody

The body is an important part of the vehicle,it is a barrier to the safety of members.There are many ways to improve vehicle safety,including: optimizing the structure,improving the process and the use of new materials.With the continuous development of technology,researchers found that filling energy-absorbing materials is one of the most effective and direct ways to improve vehicle safety.However,the current application of automotive materials have been gradually unable to meet the rapid development of the automotive industry needs,the development of new materials imminent.Carbon nanotubes,as a kind of ultra-high strength,modulus of nanoparticles,is very suitable as a filler to improve the performance of composite materials.Due to the different test conditions,the carbon nanotubes composites formed by the combination of carbon nanotubes and composites can be very different.Strictly standardizing the experimental methods and controlling the experimental conditions are very important for the preparation of carbon nanocomposites effect.Polyurethane foam can be one of the most widely used materials in the car,mainly because of its low manufacturing cost,simple manufacturing method and its own energy absorption characteristics.However,due to its energy absorption effect compared to other energy-absorbing materials(such as metal foam aluminum)is low,gradually being ignored by researchers.The emergence of nanotechnology to promote the development of new materials,researchers use these technologies can be developed with high energy absorption characteristics of low-density lightweight foam.In this paper,the carbon nanotubes and polyurethane foam in the combination of the advantages of reasonable selection of experimental methods to prepare different proportions of carbon nano-polyurethane foam,carbon nano-polyurethane foam and its filling structure of the energy absorption characteristics of the study,and applied to B-pillar,To improve the crashworthiness of the B-pillar.The specific research contents are as follows:(1)The preparation process of carbon nano polyurethane foam is described in detail.By introducing the experimental conditions and raw materials,for the characteristics of carbon nano-polyurethane foam,select the appropriate experimental materials and preparation methods.Five different proportions of carbon nano polyurethane foams were prepared as the object of this paper.(2)Study on the energy absorption characteristics of polyurethane foam.First,the quasi-static compression test was used to obtain the load-displacement curve of the foam material,and the relevant energy absorption theory was used to analyze and select the carbon nano polyurethane foam with the best energy absorption effect.The compression process of foam is mainly divided into four stages: linear elastic deformation stage,elastoplastic transition stage,yield platform stage and densification stage.Then,the material parameters were obtained by tension test and flexure test,and the simulation process of carbon nanometer polyurethane foam was simulated and verified as the data base of numerical simulation to verify the effectiveness of the simulation process.(3)Taking the stainless steel thin-walled tube as an example,the energy absorption characteristics of the polyurethane foam filled structure were analyzed.Theoretical analysis of three deformation modes of thin-walled tube: axisymmetric mode deformation,nonaxisymmetric mode deformation and mixed mode deformation.Then,three different thin-walled tube compression samples were prepared by quasi-static tensile test method.The thin-walled tube,the thin-walled tube filled with ordinary polyurethane and the thin-walled tube filled with carbon nano polyurethane were prepared by quasi-static compression test.Analyze the test results,compare the energy absorption value and the specific energy absorption(SEA)value,and verify the high energy absorption characteristics of the carbon nanometer polyurethane filled thin-walled tube.The finite element model of thin-walled tube was established,and the simulation results were verified by numerical simulation of empty thin-walled tube and carbon nano polyurethane filled thin-walled tube.(4)Crashworthiness analysis of carbon nano polyurethane foam filled B-pillar.The finite element model of moving barrier and B-pillar was established.The carbon nano polyurethane foam was filled with B-pillar structure,and the collision simulation was carried out.The intrusion rate,the invasion speed and the energy absorption of the B-pillar before and after the filling were analyzed,and the energy absorption characteristics of the carbon nano polyurethane foam were tested.Carbon nano-polyurethane foam filled body parts can improve the crashworthiness of the body,carbon nano-polyurethane foam has a lighter than the characteristics of metal foam,can be used as a kind of energy-absorbing materials.