Performance Study Of Ordered Fiber-reinforced Bionic Composites Based On 3D/4D Printing

Biological materials generally have better properties than engineered materials due to their delicate architecture,e.g.,high strength-to-weight ratio,stiffness and toughness,and adaptability.Although biomaterials offer excellent design solutions,synthesizing materials with biomimetic structures has proven to be difficult.3D printing technology,which uses a layer-by-layer cumulative,bottom-up approach to printing and molding,has shown great potential for the fabrication of bio-structural materials.However,current 3D printing technologies lack the ability to control the internal structure of materials,and there is an urgent need to develop printing technologies that can control the structure of materials,unleash the potential of 3D printing technology,and provide a means to develop bionic structural materials.In this paper,we printed oriented fiber-reinforced composites using self-developed 3D printing technology for composites with orientable fiber reinforcement,including magnetic field oriented digital optical 3D printing and flow field oriented extrusion 3D printing,and investigated the relationship between material mechanical properties and self-deformation characteristics and fiber orientation.The steel fiber-resin hybrid printing raw material was prepared,and the oriented steel fiber-reinforced resin composite was 3D printed using magnetic field orientation;the carbon fiber-polyurethane hybrid printing raw material was prepared,and the oriented carbon fiber-reinforced polyurethane composite was 4D printed using extrusion flow field orientation.The mechanical properties of steel fiber-reinforced resin materials,including strength,friction and wear properties,were characterized,revealing the relationship between material properties and fiber orientation.We characterized the mechanical properties and deformation characteristics of carbon fiber polyurethane composites,and also revealed the relationship between material properties and carbon fiber orientation.The specific research of this paper includes the following 3 aspects:(1)This review analyzes the relationship between fiber orientation of typical biomaterials and their properties,including the use of oriented fibers to selectively enhance the mechanical properties of materials and the use of oriented fibers to control the deformation behavior of materials.This paper reviews the progress of research on 3D and 4D printed bionic structural materials,including printing process methods,printing materials,and the mechanical properties and deformation characteristics of the printed materials.The problems of current research are pointed out,and the research content of this paper is proposed.(2)Stainless steel fiber-reinforced photosensitive resin composites were prepared using a magnetically-assisted oriented 3D printing process.The effects of fiber content and fiber angle on the strength as well as frictional properties of the composites were also investigated in this paper.The results show that oriented fibers can improve the strength and wear resistance of the material.The effects of fiber content and fiber angle on the mechanical as well as frictional properties of the composites were discussed.Carbon fiber-reinforced polyurethane composites were printed by direct-write 3D printing process,and the effects of printing speed,extrusion head diameter and carbon fiber content on the tensile properties of the composites were investigated to obtain optimized process parameters.The effect of fiber angle on tensile properties was investigated,and the test results showed that the smaller the angle between the fiber orientation angle and the tensile direction,the higher the tensile strength of the material.(3)Combining bionic 3D printing technology and water swelling responsive material polyurethane,we have launched the research of bionic 4D printing.Carbon fiber-reinforced polyurethane composites were printed using direct-write 3D printing technology.The effects of printing speed,needle diameter and fiber content on the fiber orientation effect and swelling rate were investigated,and the optimal process parameters affecting the carbon fiber orientation effect and swelling rate of the composite were determined,and the fiber angle and deformation mode were studied under this process parameter.A fiber-reinforced polyurethane/paper bilayer structure was printed,and the relationship between fiber orientation and deformation characteristics was studied to reveal the law of fiber angle on deformation.Using fiber orientation design,multiple forms of 4D printing shape variations were realized,and a4 D printing design method with microstructure-controlled deformation was proposed.