Modeling Of 3D Extrusion Printing Materials And Research On Preparation Of Complex Structures

3D printing technology is a rapidly developing additive manufacturing techique with capacious development foreground.3D Printing materials are the important material basis of 3D printing technology.In some ways,the development of 3D printing materials determines whether 3D printing can be more widely used.In recent years,based on the research of 3D extrusion printing technology and 3D printing materials like silicone rubber and epoxy,3D printing technology has been gradually applied to the manufacture of flexible electronic devices and bionical structures with lightweight and high strength.On the one hand,this project has presented a more accurate modeling method of soft and elastic materials by experiments,thus established the constitutive model of 3D printed silicone rubber accurately,which plays an important role in the design and optimization of 3D printed flexible devices;On the other hand,this project has created lightweight,high modulus and high strength Bouligand type bionical structures,by using the prepared fiber reinforced resin with high modulus and the developed suspension printing technology,and its mechanical properties and enhancement mechanism have been studied.The concrete contents and conclusions are as follows:(1)Mechanical property testing and accurate modeling of 3D printed silicone rubberThe project firstly tested the mechanical properties of silicone rubber,and demonstrated the accuracy of the conventional modeling method of soft and elastic materials by using the finite element software Abaqus.Then this project presented a more accurate modeling method of soft and elastic materials by experiments.We built the platform of 3D extrusion printing independently and carried out the mechanical property testing of the 3D printed silicone rubber,finally established the hyper elastic constitutive model of the 3D printed silicone rubber through the optimized modeling method.The relevant conclusions are as follows:1.We cannot describe the mechanical behavior of the silicone rubber under tension accurately depending on the uniaxial tensile testing only.It is very necessary to carry out the uniaxial tensile testing and plannar tensile testing together for establishing the hyper elastic constitutive model of the 3D printed silicone rubber under tension accurately.This modeling of method can be the same with other soft and elastic materials.2.By using the optimized modeling method of soft and elastic materials,we established the hyper elastic constitutive model of the 3D printed silicone rubber accurately at 50%strain,100%strain and 300%strain separately,and the corresponding model parameters are identified respectively.(2)Suspension 3D printing of biomimetic anisotropic reinforcement architectures with lightweight and high strengthThe project firstly prepared the fiber reinforced resin with high modulus as printing ink,then developed the suspension printing technology based on the 3D extrusion printing,and created lightweight,high modulus and high strength Bouligand type bionical structures by using this technology,mechanical properties and enhancement mechanism of reinforcement architectures have been studied.The relevant conclusions are as follows:1.We prepared the fiber reinforced resin with high modulus as printing ink,the prepared resin has superior mechanical properties,its initial modulus is about 13 GPa,which is 6times more than normal epoxy resin,and which is equivalent to 1/15 of the steel's modulus.2.We created Bouligand type biomimetic anisotropic reinforcement architectures with lightweight,high modulus and high strength,by using the prepared fiber reinforced resin with high modulus and the developed suspension printing technology.The compression testing shows that the fracture load of anisotropic reinforcement architectures is 3 times more than normal isotropic architectures,and the anisotropic architectures have better impact resistance.Also,we have analyzed the reinforcement mechanism of anisotropic architectures.