Composite material: composite material is a new material formed by the combination of two or more heterogeneous, heteromorphic and anisotropic materials. It is generally composed of matrix components and reinforcements or functional components. Carbon fiber: in short, it is a fibrous carbon material, which has the characteristics of high strength, high modulus, low density, corrosion resistance and so on. Graphite fiber: carbon fiber with layered hexagonal lattice graphite structure with graphitized molecular structure and carbon content higher than 99%. After high-temperature heat treatment, the internal graphitization degree of carbon fiber will be improved. It is generally believed that carbon fiber after high-temperature heat treatment above 1800 ℃ is called graphite fiber. Epoxy resin: epoxy resin refers to a kind of polymer whose molecule contains more than two epoxy groups. It is the polycondensation product of epichlorohydrin and bisphenol A or polyol. Due to the chemical activity of epoxy group, it can be opened by a variety of compounds containing active hydrogen, cured and crosslinked to form a network structure. Therefore, it is a thermosetting resin. Bisphenol A epoxy resin not only has the largest output and the most complete varieties, but also the new modified varieties are still increasing and the quality is improving. Thermosetting: thermosetting refers to the property that can not be softened, repeatedly molded or dissolved in solvent when heated. Bulk polymers have this property. Thermoplasticity: thermoplasticity refers to the property that substances can flow and deform when heated and maintain a certain shape after cooling. Most linear polymers exhibit thermoplasticity and are easy to be extruded, injected or blow molded. Tensile strength: tensile strength refers to the maximum stress that the material bears before breaking, which indicates the ability of the material to resist damage. Tensile modulus: the tensile modulus refers to the elasticity of the material during stretching. The value is the ratio of the force required to stretch the material per unit length along the central axis to its cross-sectional area, which represents the ability of the material to resist deformation. Poisson's ratio: Poisson's ratio refers to the ratio of transverse deformation to axial deformation of a material under uniaxial tension or compression, also known as transverse deformation coefficient. Sizing agent: the carbon fiber is wrapped with a layer of polymer by impregnation before winding, which is used to protect the carbon fiber and improve the bonding strength between the carbon fiber and the matrix. Elongation at break: the ratio of the difference before and after stretching to the length before stretching when the fiber is pulled to break by external force is called elongation at break, expressed in percentage. Specific strength: the specific strength is the strength of the material (the force per unit area when disconnected) divided by its density. Also known as strength weight ratio. Specific modulus: specific modulus is the elastic modulus of unit density. It is a material property, also known as stiffness mass ratio or specific stiffness. Toughness: the ability of a material to absorb energy during plastic deformation and fracture. The better toughness, the less possibility of brittle fracture. Isotropy: isotropy refers to the characteristic that the physical and chemical properties of an object will not change due to different directions, that is, the performance values of an object measured in different directions are exactly the same, also known as homogeneity. Anisotropy: anisotropy means that all or part of the chemical and physical properties of a substance change with the change of direction, showing different properties in different directions. Prepreg: prepreg is an intermediate material, which impregnates continuous fiber or fabric with resin matrix under strictly controlled conditions to make the composition of resin matrix and reinforcement. Unidirectional cloth: unidirectional cloth, referred to as UD cloth for short, refers to a kind of cloth with a large number of carbon fiber yarn in one direction (usually warp direction) and only a small amount of fine yarn in the other direction. As a result, all the strength of the cloth is in the first direction. 3K cloth: a kind of cloth woven with 3K carbon fiber tow, which is divided into plain, satin and twill. It is generally used on the surface of carbon fiber products. Pre oxidation: pre oxidation refers to the pre oxidation process of carbon fiber precursor before carbonization, also known as stabilization. The main purpose is to make the precursor incombustible during carbonization. Carbonization: refers to the reaction process of heating and decomposition of carbon fiber precursor or pre oxygen wire under the condition of isolated air, and finally produce carbon fiber. Graphitization: refers to the process of changing the arrangement of carbon atoms in carbon fiber from disordered graphite structure to ordered graphite crystal structure after high-temperature heat treatment. PAN based: polyacrylonitrile based. The carbon fiber carbonized with polyacrylonitrile fiber as precursor is called polyacrylonitrile based carbon fiber. Pitch based: carbon fiber carbonized with pitch fiber as precursor becomes pitch based carbon fiber. Viscose base: carbon fiber carbonized with viscose filament as precursor, which becomes viscose based carbon fiber. Precursor: an organic fiber that is spun and used to produce carbon fibers. Spinning: also known as chemical fiber forming. A process for manufacturing chemical fibers. The process of making some high molecular compounds into colloidal solution or melting into melt and then pressing out from the fine hole of spinneret to form chemical fiber. Full standard: carbon fiber imported from Japan without cutting standard is called full standard. Half standard: because Japan restricts the circulation of carbon fiber exported to China, a tracking code is set in the product label. In order to prevent Japan from tracing, the label tracking code is cut off in China. This carbon fiber is half standard carbon fiber. Small tow: it is generally believed that carbon fibers smaller than 24K tow are small tow carbon fibers, mainly 1K, 3k, 6K, 12K and 24K. Large tow: it is generally considered that carbon fibers larger than 24K tow are large tow carbon fibers. Wet spinning: one of the main spinning methods of chemical fiber, referred to as wet spinning. Dry jet wet spinning: dry jet wet spinning refers to the solution spinning method with the characteristics of both dry jet and wet spinning. The stretching ratio of the nozzle is high. When entering the wet coagulation bath, the tow expansion during wet spinning can be improved. Therefore, the structure is dense, the spinning speed is high, the primary silk has certain strength, and high-performance fibers can be obtained after post-treatment. Coefficient of thermal expansion: expansion and contraction of objects due to temperature change. The change ability is expressed by the change of length caused by the change of unit temperature under isobaric conditions, that is, the coefficient of thermal expansion. Disordered graphite structure: the carbon six element ring network plane gradually increases, and begins to stack parallel to each other and at equal intervals, but the carbon atoms on each network plane do not have AB in the graphite crystal The regularity of stacking sequence, that is, it has not yet reached the three-dimensional ordered state. Such a structure is called disordered graphite structure. Graphitization degree: after high-temperature heat treatment, the carbon atom structure of carbon fiber continues to approach the perfect graphite crystal structure, and the graphitization degree is taken as the parameter of the degree approaching the perfect graphite crystal structure. Plain weave: the fabric made of plain weave is called plain weave, that is, warp and weft are interwoven every other yarn. This kind of cloth is characterized by many interlacing points, firm texture, strong scraping, flat surface, light and thin, good wear resistance and good air permeability. Satin weave: satin weave is the general name of various specifications of satin weave cloth. It is a kind of fabric weave that is evenly distributed but discontinuous by separate weave points on two adjacent warp or weft yarns. Twill: twill is a cotton fabric with two upper and lower twills and 45 ° left inclination. The front twill pattern is obvious Density per unit area: for carbon fiber cloth or carbon fiber prepreg, it is generally grams per square meter. Warp: a string of yarns extending along the length of the loom from which the yarn is spun into a thread along the length of the fabric. Weft yarn: in weaving, the yarn used in radial direction is warp yarn, and the yarn used in weft direction is weft yarn. Sandwich material: in CFRP laminates, in order to improve the bending moment resistance of laminates, a foamed material or honeycomb material is added between CFRP plates. Three dimensional weaving: also known as three-dimensional weaving. On the weft knitting machine, shaped or sheet fabrics with three-dimensional structure are woven by means of retracting and releasing needles, holding horizontal rows, wedge weaving or multi-layer weaving. Multi axial fabric: multi-layer composite fabric formed by binding warp, weft and oblique three-way full width weft lining yarn together. Short cut carbon fiber: cut carbon fiber short and use it to strengthen plastics. Hot melt prepreg: a method of melting the prepreg resin by heating and impregnating it into the fiber. It is a kind of prepreg production process. Solution prepreg: it is a method of dissolving the prepreg resin with organic solvent and impregnating it into the carbon fiber. It is a kind of prepreg production process. Coupling agent: a plastic additive that improves the interfacial properties between synthetic resin and carbon fiber. Fiber content: carbon fiber content per unit area. Resin content: resin content per unit area. Bonding: a method of bonding two carbon fiber composite parts together with adhesive. Mechanical connection: the connection method of connecting carbon fiber composite parts together by bolt or riveting. Z-pin connection: using Z-pin technology, unidirectional composite materials are extruded into thin rods (commonly known as Z-pin) and pinned into uncured prepreg or fiber preform. After curing, Z-pin forms an "anchored" Z-direction reinforcement. Hybrid connection: both adhesive connection and mechanical connection are adopted. Curing: the process in which the resin is heated or reacted with curing agent, and the internal cross-linking reaction occurs, and the resin changes from soft to hard cured materials. Co curing: two carbon fiber composite parts are connected by simultaneous curing. Curing temperature: the temperature at which the curing reaction occurs is the curing temperature. Low temperature curing: generally 60-80 ℃ curing is low temperature curing. Medium temperature curing: generally 120-130 ℃ curing is medium temperature curing. High temperature curing: generally, curing above 150 ℃ is high temperature curing. Aging: during the use of polymer materials, due to the comprehensive action of environmental factors such as heat, oxygen, water, light, microorganism and chemical medium, the chemical composition and structure of polymer materials will change a series, and the physical properties will deteriorate accordingly, such as hardening, tackiness, embrittlement, discoloration and loss of strength. These changes and phenomena are called aging, The essence of polymer aging is the change of its physical or chemical structure. Lamination: the process of laminating composite materials layer by layer from unidirectional plates. Structural component: the component used to carry load, which is a structural component. Single layer board: basic structural unit of continuous fiber composite material. Laminate: a composite laminate stacked layer by layer using a single-layer board. Ply angle: the angle between the unidirectional fiber ply direction and the main axis direction of the composite material. Ply ratio: the ratio of the number of fiber plies in a certain direction to the total number of plies. Stiffened plate: in the structural design, the stiffener is used in the direction perpendicular to the panel to improve the bearing capacity of the panel and the overall structure. The stiffener and the panel are an integral structure, or connected together by cementation or welding. Glass transition temperature: glass transition temperature refers to the temperature corresponding to the transition from high elastic state to glass state or glass state to high elastic state. Interface: generally refers to the bonding area between carbon fiber and matrix Degumming: the phenomenon that an object with glue or adhesive film attached to its surface falls off due to external or internal causes is called degumming. Delamination: due to the weak strength between layers of laminated plates, the separation between layers occurs under stress. Bag press molding: bag press molding refers to a method of uniformly pressing the reinforced plastic between the rigid mold and the elastic bag to become a part by receiving the fluid pressure with the help of the plastic bag film. Autoclave: as the autoclave is a pressure vessel, its common structure is a cylinder with one end closed and the other end open, which provides a basis for the compaction and curing of advanced composite parts
