132 results about "Specific strength" patented technology

The invention belongs to the technical field of metal material engineering, and relates to a light high-toughness low-cost aluminum alloy and a preparation method thereof.The alloy comprises, by mass, 7.0%-9.2% of Mg, 2.5%-4.0% of Zn, 0.06%-0.20% of Zr, 0.01%-0.03% of Sb, main impurities including Fe smaller than or equal to 0.15%, Si smaller than or equal to 0.12%, other single impurities smaller than or equal to 0.05%, the total impurity smaller than or equal to 0.15% and the balance Al. Compared with 2xxx series and 7xxx series aluminum alloys, the alloy has certain advantages in the aspects of density, specific strength, ductility, corrosion resistance and the like, and has a remarkable cost advantage compared with a low-density aluminum-lithium alloy, so that the core competitiveness of an alloy product is improved, and the alloy product has the potential of becoming a next-generation commercial aluminum alloy.

The invention discloses an intelligent detection system and method for the fracture specific strength of cotton fibers, and relates to the technical field of cotton fiber detection, and the intelligent detection system for the fracture specific strength of the cotton fibers comprises a sampling module, an image acquisition module, a resistance measurement module, a strength measurement module and a central control module. The sampling module is used for sampling on a cotton fiber sample and constructing the sample into a to-be-detected cotton fiber bundle; the image acquisition module is used for acquiring image information of a to-be-detected cotton fiber bundle; the resistance measurement module is used for measuring resistance information of the to-be-detected cotton fiber bundle; the strength measurement module is used for snapping the to-be-detected cotton fiber bundle from a fracture area of the to-be-detected cotton fiber bundle and recording real-time tension information and displacement information of the fracture area; the central control module is in communication connection with the image acquisition module, the resistance measurement module and the strength measurement module. According to the invention, the detection of the cotton fiber fracture specific strength in a non-standard laboratory environment can be realized.

The utility model discloses a composite material support with a C-shaped cross section and a negative angle and a forming die thereof, the composite material support comprises a body with a C-shaped cross section, the body comprises an upper plate, a middle plate and a lower plate, one edge of the upper plate is connected with the upper edge of the middle plate into a whole, the lower edge of the middle plate is connected with one edge of the lower plate into a whole, and the lower plate is connected with the lower plate into a whole. A C-shaped structure is defined by the upper plate, the middle plate and the lower plate, an integrated rectangular frame is defined after a C-shaped opening of the body faces outwards, the upper plate on the two opposite edges of the rectangular frame is of a negative angle structure, namely the upper plate inclines outwards and downwards, so that the included angle between the upper plate and the middle plate is an acute angle, and the lower plate and the middle plate form a right angle. The upper plates and the middle plates of the other two opposite frames of the rectangular frame are perpendicular, and the lower plates and the middle plates are perpendicular. The composite material support is low in machining cost and high in specific strength and specific stiffness.

The application belongs to the field of high-entropy alloys, and particularly relates to a preparation method of an ultra-high strength and plasticity product Fe50Mn30Co10Cr10 alloy. Firstly, a cast slab is prepared through vacuum induction melting, then the cast slab is subjected to multi-pass hot rolling with a reduction ratio of 70% to 75%, and after pickling, the cast slab is subjected to multi-pass warm rolling with a reduction ratio of 80%, and finally, high-temperature short-time annealing is carried out at 1050 to 1150 DEG C to obtain a final annealing plate. In the application, the phase transformation behavior in the alloy deformation process is inhibited by controlling the hot rolling and warm rolling temperatures, and the rolling plasticity of the material is improved. Meanwhile, by optimizing the annealing process, the grains are refined as much as possible, and a certain dislocation density is retained, and the strength and plasticity of the alloy are improved through the comprehensive action of multiple strengthening mechanisms. The prepared Fe50Mn30Co10Cr10 alloy has a tensile strength of 1050 to 1280 MPa, an elongation of 35% to 58%, and a strength and plasticity product of 40 to 73 GPa.

The invention discloses a vertical-horizontal mixed enhanced selective laser melting lattice structure based on a face-centered cube (FCC) and a preparation method of the vertical-horizontal mixed enhanced selective laser melting lattice structure. According to the method, starting from a basic FCC lattice unit, firstly, an in-plane enhanced transition lattice structure FCC-H (FCC-Horizon) is formed through a crossed structure of an inclined main rod and an auxiliary rod perpendicular to the main rod; the secondary auxiliary rods are distributed in a radial mode to construct a continuous bridging grid by further optimizing the rod piece connecting mode and the diameter proportion, and finally the vertical-horizontal mixed enhanced FCC-VH (FCC-Vertical Horizon) lattice structure is obtained. According to the structure, through the synergistic effect of the inclined main rods and the auxiliary rods perpendicular to the main rods, the compressive strength, the specific stiffness, the specific strength and the specific energy absorption of the structure are remarkably improved while the light weight is kept. According to an experiment, 316L stainless steel powder is adopted, an FCC-VH lattice structure is prepared through a selective laser melting (SLM) technology, the compression deformation mode of the FCC-VH lattice structure is converted into multi-node cooperative bearing from local buckling of a basic FCC, and the overall compression performance is more remarkably improved.

The present invention discloses a heterogeneous metal laminated composite armor and a preparation method thereof, comprising the following steps: A. Prepare different heterogeneous metal elements respectively and stack them along the thickness direction; B. Vacuum package the periphery of the interface of the stacked heterogeneous metal elements; C. Achieve metallurgical bonding of the heterogeneous metal interfaces through stacked forging and heat preservation diffusion treatment; D. Obtain a heterogeneous metal laminated composite armor with specific specifications through forging and precision rolling. The present invention uses a high-strength metal as the face plate and a high-toughness metal as the back plate, and at least one of the two metals is a high specific strength material. Through stacked forging and heat preservation diffusion treatment, strong metallurgical bonding is achieved at the heterogeneous metal interfaces, and combined with subsequent forging and precision rolling processes, a lightweight metal composite armor plate with excellent anti-ballistic performance is prepared, improving the anti-multi-projectile strike ability and comprehensive protection performance of the armor, and solving the problem of weak interfacial bonding strength of heterogeneous materials.

The invention relates to the technical field of transmission shaft machining, in particular to a kinetic energy transmission shaft body and a machining process integrating pultrusion, weaving, winding and glue injection, the kinetic energy transmission shaft body comprises a shaft body, the shaft body is formed by winding a continuous composite material reinforced thermosetting resin prepreg tape, and a composite material comprises a reinforcing material, a base material, a functional additive and filler; a plurality of limiting grooves are formed in the inner wall of the shaft body, the limiting grooves extend in the axial direction of the shaft body, the length of the limiting grooves is consistent with that of the shaft body, and pultrusion, weaving, winding and glue injection processes are organically integrated, so that the manufactured kinetic energy transmission shaft body has high specific strength, high torsional rigidity, excellent interlayer bonding performance and good dynamic stability; meanwhile, a limiting groove can be precisely machined in the inner wall of the shaft body, the high-precision torque transmission requirement is met, and the defects that a traditional metal shaft body is heavy and prone to corrosion and layers of a single composite material shaft body are prone to layering are overcome.

The present invention discloses a process and a plate for three-dimensionally weaving a plate with channels, comprising: arranging yarns on a three-dimensional weaving base according to the shape of the plate, not arranging yarns in the empty positions of the channels, and weaving the plate with channels in three dimensions according to a four-step method. In the present invention, a three-dimensional weaving plate with channels is made using three-dimensional weaving technology. This plate has good structural integrity and strong load-bearing performance. It will not delaminate after being subjected to force. The design of its channels can reduce the weight of the plate while also having the function of thermal insulation. Furthermore, the shape, arrangement, and number of the channels in the present invention can be designed according to the working conditions of the product, which is conducive to reasonably improving the mechanical contribution rate of the fiber. The plate with channels of the present invention has high specific strength and high specific modulus, and can be matched with the selection of materials to meet the needs of aerospace, rail transportation, sports and leisure, construction and other fields for different composite material plates.

According to the high-toughness superstructure manufacturing method based on gradient bionic spiral construction, a composite material superstructure with the excellent mechanical property is constructed through the synergistic effect of gradient bionic spiral laying layer design and a Z-pin anchoring technology, in a gradient bionic spiral laying layer, the spiral angle changes in a gradient mode, Z-pin anchoring penetrates through a composite material laminated plate, and the Z-pin anchoring technology is used for anchoring the composite material laminated plate. According to the manufacturing method, a three-dimensional reinforced network is formed, the interlayer strength and impact resistance are remarkably improved, the high-toughness superstructure is manufactured through an autoclave forming process, cooperative reinforcement of gradient bionic spiral construction and a Z-pin anchoring effect is achieved, and the prepared superstructure has high specific strength, high toughness and excellent layering resistance.

The application discloses a high specific strength high-elongation 6-series aluminum alloy anti-collision beam, which comprises a base, the upper side walls of the base are symmetrically fixedly connected with vertical plates, the opposite sides of the two vertical plates are fixedly connected with support plates, the upper side walls of the two support plates are fixedly connected with a smelting furnace, a stirring mechanism is arranged on the smelting furnace, a feeding port is formed in the upper side wall of the smelting furnace, and arc-shaped blocks are arranged on the inner bottom wall of the smelting furnace. The anti-collision beam combines the advantages of 6082 alloy and 7003 alloy, has good extrusion forming performance, the strength is greater than 340 MPa, the elongation is greater than or equal to 15%, and the elongation is improved by more than 10% compared with the 6082 alloy. The rare earth rhenium is added to refine the grains and improve the alloy strength, and the 6-series profile is subjected to double-stage aging strengthening, so that the elongation of the alloy is further improved.

The application discloses a preparation method of a high-temperature / high-strength / high-toughness heterogeneous structure Ti6Al4V alloy, which takes a Ti6Al4V alloy forge piece as a matrix, takes Ti6Al4V alloy powder and Ti6.5Al3,5Mo1,5Zr0.3Si alloy powder as deposition materials, controls the alloy powder output by adjusting the rotating speed of a powder feeding barrel, continuously changes the Ti6.5Al3,5Mo1,5Zr0.3Si mass percentage doped into the Ti6Al4V powder in the thickness direction, and prepares a symmetric gradient heterogeneous structure titanium alloy by laser deposition. The application fully utilizes the high specific strength of the Ti6Al4V alloy and the high-temperature characteristics of the Ti6.5Al3,5Mo1,5Zr0.3Si alloy, and the heterogeneous structure Ti6Al4V alloy prepared by the method has excellent tensile strength and impact toughness. The application is suitable for the preparation process of the 3D printing heterogeneous structure Ti6Al4V alloy which is easy to realize.

This invention discloses a structural strength optimization method based on a triangular fractal algorithm, relating to the field of structural optimization design in civil engineering. The method includes the following steps: Ⅰ. Setting the geometric and material parameters of initial members and calculating their buckling critical load and specific strength; Ⅱ. Setting the geometric and material parameters of the reinforced members in the first iteration and calculating their buckling critical load and specific strength after iteration; Ⅲ. In each iteration, changing the radius of the added members, calculating the maximum specific strength of the triangular fractal structure in each iteration, and recording the corresponding member radius. The fractal structure generated after multiple iterations of this invention can withstand greater loads and has higher strength. It maintains increased strength even with further increases in the number of iterations, making the structure less prone to failure. The fractal structure generated after multiple iterations can withstand greater loads and has higher strength, which is helpful for optimizing engineering solutions.

The invention provides a carbon fiber rubber-coated roller and a wire cutting machine. The carbon fiber rubber-coated roller comprises a carbon fiber tube body, the shaft seats are arranged at the two ends in the carbon fiber tube body, and the shaft seats are combined with the carbon fiber tube body through fixing structures; each shaft seat is connected with one shaft core, and one end of each shaft core extends to the outside of the carbon fiber tube body; and the working layer covers the outer part of the carbon fiber pipe body. The carbon fiber rubber-coated roller has the advantages that compared with an existing roller made of a metal material, the whole carbon fiber rubber-coated roller is lighter in overall weight, the energy consumption of the carbon fiber rubber-coated roller in the working process can be remarkably reduced, and the carbon fiber rubber-coated roller has higher specific strength and specific modulus; the light weight of the product can be ensured under the condition of the same strength, and the strength of the product can be higher under the condition of the same weight; and meanwhile, the product also has good water resistance, rust resistance, temperature resistance and low possibility of deformation, and is good in stability.

The present invention discloses a combustible casing for an underground coal gasification channel and a preparation method thereof, belonging to the technical field of petroleum industry pipe manufacturing. The preparation process of the combustible casing is simple. The combustible casing is composed of 0.2-1.0Zr, 1.0-5.0Zn, 1.0-5.0Al, 7.0-13.0Gd, 3.0-6.0Y, 3.0-6.0Nd, and the remainder being Mg and impurities in mass percentage. After being cast and turned into an ingot, the ingot is solution treated and extruded, and then subjected to aging treatment. Finally, the combustible casing is prepared, which has sufficient space for normal operation and has the characteristic of being burned and consumed above a specific temperature. The casing has a rationally designed alloy element composition, low density, high specific strength, excellent room temperature and high temperature strength, and the characteristics of being burned and consumed above the specific temperature.

The application relates to the field of fiber preparation, and discloses a kind of ultra-high molecular weight polyethylene fibers with adsorption and its preparation method and application, the raw material of the ultra-high molecular weight polyethylene fiber prepared includes ultra-high molecular weight polyethylene powder, antioxidant and filler;Wherein, the antioxidant is 0.2-1wt% of the ultra-high molecular weight polyethylene powder, and the filler is 0.5-3wt% of the ultra-high molecular weight polyethylene powder;Wherein, the filler is obtained by reacting metal salt and polybasic acid organic ligand dissolved in a first solvent, using the technical scheme provided by the application, the ultra-high molecular weight polyethylene powder has good corrosion resistance, the adsorption performance of ultra-high molecular weight polyethylene is improved by filler, the ultra-high molecular weight polyethylene fiber with adsorption is prepared, the specific strength is high, the specific modulus is high, and the adsorption capacity is as high as 200-600mg / g.

The present invention discloses a lightweight, high-strength, high-energy-absorbing porous TWIP steel and a preparation method thereof. High-purity metal Fe, Mn powder and high-purity graphite are weighed and mixed in a certain proportion, and then mechanical alloying (MA), pore formation and high-temperature sintering are performed in sequence to obtain porous structure TWIP steel with different pore sizes and porosities. The alloy has the characteristics of light weight, high specific strength and high energy absorption, and can be used as a new generation of impact-resistant, buffering and energy-absorbing materials in many fields. At present, the research and development of porous metals mainly focuses on aluminum, copper, titanium, magnesium, nickel alloys, stainless steel, etc., and there are almost no reports on the porous preparation of TWIP steel. The present invention adopts a formed powder sintering method, and utilizes MA combined with pore formation and high-temperature sintering to realize the direct preparation of lightweight porous TWIP steel with controllable pore size and porosity. The unique TWIP effect and high work hardening ability of TWIP steel are utilized to obtain a higher specific strength and extremely high buffering and energy-absorbing ability.

The present invention provides an amorphous porous aluminum alloy material, a preparation method and an application thereof. The composition of the amorphous porous aluminum alloy material is Al 70 (CuCo x ) 20 (TiCo y )9(Sc / Er)1, where x is from 1 to 4 and y is from 1 to 2. A plurality of holes are uniformly distributed inside, the diameter of the holes is 400 - 700 μm, the porosity is 45 - 60%, and the density is 1.6 - 2.0 g / m 3 . The amorphous porous aluminum alloy material has a metal matrix composite foam preparation process with strong designability and a low error tolerance rate in the production process. It not only has a high density and porosity, but also the hole sizes are relatively uniform. It can absorb energy through the collapse of dense holes, and thus has a high impact absorption and buffer protection function. Moreover, the dense holes can increase the thermal resistance of the interface, reduce the heat conduction performance, and at the same time have a low density and excellent mechanical properties such as specific strength and specific stiffness.

The invention discloses a polymer alloy plastic bridge and a preparation method thereof, and relates to the technical field of cable bridges, the polymer alloy plastic bridge comprises a main groove body, the main groove body is integrally formed by a bottom and two side plates, the bottom and the two side plates of the main groove body are each of a three-layer composite structure, the top of the main groove body is detachably connected with a cover plate through a buckle assembly, and the cover plate is detachably connected with the bottom of the main groove body. The three-layer composite structure sequentially comprises an alloy plastic base plate, a honeycomb-shaped reinforcing rib layer and a stainless steel plate from outside to inside. Through the design of the three-layer composite structure, the performance is synergistically enhanced, compared with a traditional plastic bridge, the weight is reduced by 30% or above, the bending strength is improved by 50%, the three-layer structure is firmly combined through the co-extrusion-mold pressing-bonding technology, the limitation of a bridge made of a single material on strength, weather resistance or weight is solved, and the service life of the bridge is prolonged. The structure has high specific strength and specific stiffness, the weight of the bridge can be effectively reduced while the overall strength of the bridge is guaranteed, installation and transportation are convenient, and the construction cost is reduced.

The invention discloses a preparation method capable of reducing the grain size and segregation layer of a 6-series alloy, and relates to the technical field of metal material preparation, the preparation method comprises the following specific steps: S100, preparing raw materials; weighing an aluminum ingot, a pure magnesium ingot and a ferrosilicon alloy according to the standard components of the 6-series alloy by using an electronic analytical balance, wherein the weighing error of each raw material is + / -0.01%; through the magnetic field constraint solidification technology, the alternating magnetic field with the specific strength and frequency is applied in the 6-series alloy solidification process, alloy grains are effectively refined, formation of a segregation layer is reduced, limitation of the traditional solidification technology is broken through, uniform distribution of solute atoms is promoted through the magnetic field effect, and the alloy quality is improved. Therefore, the overall uniformity and the mechanical property of the alloy are improved, the precise control and the high uniformity of the magnetic field intensity are ensured by combining the magnetic field constraint solidification with the superconducting magnet, and a reliable means is provided for microstructure optimization of an alloy material.

The invention provides a manufacturing and performance verification method of a spray-formed aluminum alloy forge piece for a helicopter, and the method comprises the following steps: carrying out spray forming on uniformly mixed metal powder to obtain a spray-formed aluminum alloy ingot blank; carrying out extrusion hot processing on the spray-formed aluminum alloy ingot blank; forging the ingot blank subjected to extrusion hot processing; the forged forge piece is subjected to heat treatment; and carrying out performance verification on the forged piece subjected to heat treatment. The spray-formed aluminum alloy forge piece manufactured based on the method can meet the weight reduction design requirements of typical bearing frames and other parts of helicopters, structural weight reduction is achieved, and the development requirements of ultra-light structures and high specific strength are met.

The application discloses an insect exoskeleton morphological layup composite panel, a sandwich structure and a preparation method. The sandwich structure comprises two pieces of bionic layup composite panels and a piece of aramid honeycomb core layer. The bionic layup composite panel draws lessons from the spiral stacking microstructure of the insect exoskeleton, the layup design considers the symmetry and balance requirements of the composite material, a fixed rotation angle is introduced between adjacent fiber layers, and the rotation angle is taken as a period of 180 degrees, and after a plurality of periods are laid and heat-pressed and cured, the bionic layup composite panel is obtained. The bionic layup design effectively reduces the interlaminar shear stress of the composite material, weakens the inherent anisotropy of the composite material, and improves the transverse bearing capacity and impact resistance. The bionic layup composite panel and the aramid honeycomb core layer have the advantages of high specific strength, high specific stiffness, impact energy absorption, vibration and noise reduction, electromagnetic shielding and the like, and a structure and function integrated material with more excellent comprehensive performance is obtained, and the structure and function integrated material is expected to be widely used in main load-bearing structures of various spacecrafts.

The invention belongs to the technical field of metal material preparation, and particularly relates to a preparation method of nanopore reinforced high-strength plastic low-density stainless steel, which is characterized by comprising primary rolling, annealing, secondary rolling and tempering. The method has the beneficial effects that (1) the nano holes are innovatively introduced into the stainless steel sintered felt, the strength of the steel is successfully improved through interface strengthening of the nano holes, the density of the steel is reduced due to volume loss caused by the holes, the specific strength of the steel is further improved, the steel keeps excellent ductility due to the excellent deformation capacity of the holes, and the strength of the steel is improved; the strength is increased, and the density is reduced; and (2) the strength of the nanopore reinforced stainless steel is improved by 2.5 times and the specific strength is improved by 2.78 times compared with that of traditional compact stainless steel under the condition that plasticity is not lost, the strength and plasticity of the stainless steel are reinforced and are far better than those of existing stainless steel materials, and more importantly, a new thought is provided for the strength and plasticity design of steel and iron materials through a nanopore reinforcing mechanism.

The invention relates to the technical field of hydroelectric generation, in particular to an impulse turbine and a water bucket. Comprising an upstream face layer made of a metal material; the downstream surface layer is made of a carbon fiber composite material; wherein the upstream face layer and the downstream face layer are connected to form a double-bowl-shaped water bucket structure which is symmetrical along the water diversion blade. By combining the high wear resistance of the metal material with the high specific strength and high specific stiffness of the carbon fiber composite material, the runner bucket blade which is higher in strength, higher in abrasion resistance and lighter in weight is formed. Under the conditions of high water head and sediment, deformation and cracking of the bucket and even damage of bucket breakage are avoided, and the service life of the bucket is prolonged.

The invention discloses a bimodal structure hollow glass bead / epoxy resin floating body material based on a bimodal optimal strength ratio and a preparation method of the bimodal structure hollow glass bead / epoxy resin floating body material. A bimodal optimal strength ratio formula is adopted, and the stress concentration ratio and density distribution of a hollow glass bead / polyether-ether-ketone composite material are optimized; the composite foam material which is high in strength ratio, low in density and complete in structure is achieved, the performance of the composite material is improved, a universal and normative formula is provided for industrial production, the method can be applied to calculation related to various microbead stress relations, the problems of uneven microbead distribution, stress concentration of buoyancy materials and over-high density accumulation are solved, and the application prospect is wide. The stability and durability of the solid buoyancy material are improved, the specific strength of the solid buoyancy material is improved, and a large amount of test cost is saved.

The invention relates to the technical field of composite material manufacturing, in particular to a preparation method and application of a PEEK composite material. The preparation method of the PEEK composite material comprises the following steps: carrying out high-temperature oxidation and silane coupling agent impregnation pretreatment on short carbon fibers, and meanwhile, carrying out dry premixing on polyimide microspheres and nano silicon dioxide; feeding and stirring step by step according to the proportion to form a premix with uniformly distributed components; carbon fibers are supplemented in a lateral feeding mode, and melt blending and granulation are completed in cooperation with precise temperature control; and finally, drying the composite material particles, and carrying out injection molding or compression molding to obtain a finished product. The prepared PEEK composite material has excellent comprehensive performance: the material density is extremely low, and the specific strength is excellent; a multi-scale enhanced network is constructed in the composite material, high rigidity and high toughness are both considered, and the composite material has excellent impact resistance; the composite material has a self-lubricating property and outstanding wear resistance and fatigue resistance.

The invention discloses a high-space-utilization-rate support / mast for a space structure, and belongs to the technical field of aerospace. The stent / mast is of a tubular structure in which material portions of higher strength are arranged on opposite sides of the tubular structure; the thermoplastic resin material part is connected with the edge part of the material part with high specific strength to form a pipe main body structure with a tubular structure; the slotted hole gaps are formed in the positions, opposite to each other, of the material parts with the high specific strength on the two opposite sides. During storage, pipe section parts, located outside the two ends of the slotted hole gap, of the tubular structure are flattened oppositely, flattening creases occur at the thermoplastic resin material parts, the two flattened pipe section parts are wound on the core material, and the wound flattened pipe section parts are restrained through binding belts; and the two coiled and restrained pipe section parts realize the turning direction orthogonal to the flattening direction through the slotted hole gap. The folding folding bed has the advantages of being convenient to store, small in occupied space after being stored and high in structural rigidity after being unfolded.

The invention discloses a composite material corrugated curved wall honeycomb structure and a preparation method thereof, and belongs to the technical field of lightweight composite material structures. The structure is formed by arranging a plurality of honeycomb units in a staggered mode, the wall face of each honeycomb unit is of a geometrical structure that outwards-protruding arc walls and inwards-concave arc walls are alternately distributed, the central angle theta of each arc wall is (0, 85), and the out-plane compression resistance and buckling resistance are remarkably improved through the corrugated curved wall design. The preparation method comprises the steps of prepreg laminated plate hot-pressing softening, corrugated mold array assembling, curved surface winding forming, segmented variable-temperature curing and the like, a process system combining a polytetrafluoroethylene detachable mold and a self-adaptive adjustable clamp is adopted, and the problem of interface weakening caused by interlocking or glue joint in a traditional process is solved. In the curing process, residual stress distribution is optimized through a two-stage process of pre-tightening forming and high-temperature strengthening. The composite material has high specific strength and process flexibility, and is suitable for high-bearing and light-weight requirements in the fields of aerospace, ships, new energy automobiles and the like.

The present invention discloses a three-dimensional woven composite leaf spring landing gear preform imitation molding tool and molding method, including a tool frame, a core mold, five clamps, and five connecting rods. The three-dimensional woven composite leaf spring landing gear structure preform includes nine regions: uniform cross-section region 1, variable cross-section region 1, uniform cross-section region 2, variable cross-section region 2, uniform cross-section region 3, variable cross-section region 3, uniform cross-section region 4, variable cross-section region 4, and uniform cross-section region 5. The leaf spring has vertical sections on both sides and a circular arc section in the middle, forming a symmetrical structure. The fabric thickness varies in different regions. Variable thickness integrated weaving is adopted during the weaving process. The fabric region includes connecting warp and weft yarns. The present invention can solve the defects of existing landing gear preforms that are woven in blocks and cannot be integrated, and achieve better dimensional control and good mechanical properties. The use of three-dimensional woven composite materials not only has the characteristics of high specific stiffness and high specific strength, but also has excellent anti-delamination and impact resistance.

The present invention relates to the technical field of green bamboo building materials, and specifically to a device for measuring the long-term tensile strength of a recombinant bamboo structure beam-column, which includes a base. A test frame is fixed on the base. A lifting plate is slidably connected to the test frame. A bottom plate parallel to the lifting plate is arranged below the lifting plate. Through holes for the beam-column to pass through are respectively formed in the middle parts of the lifting plate and the bottom plate. The lifting plate and the bottom plate are connected by a hydraulic cylinder. Two sets of symmetrically arranged positioning components are arranged between the lifting plate and the bottom plate. A connecting rope is connected between the two sets of positioning components. The two sets of positioning components are respectively connected to the lifting plate and the bottom plate. The present invention can perform segmented tensile strength measurement on different regions of a relatively long recombinant bamboo structure beam-column to obtain more detailed and specific strength measurement results, and there is no need to set up an additional power driving device, so that the tensile strength measurement work and the adjustment of the measurement position are linked and coordinated, which is beneficial to improving the measurement efficiency.

The application discloses a preparation method of a force-thermal superstructure with light load bearing and laser protection, adopts a double-point lattice structure design of light metal skeleton lattice and ablation type resin matrix composite lattice nested with each other, utilizes a 3D printing forming process, combines new technical advantages of selective forming of various materials, and realizes integrated high-precision forming of the force-thermal superstructure with light load bearing and laser protection by means of finite element numerical simulation and calculation optimization. The superstructure prepared by the method improves the specific strength and specific stiffness of the structure within the design range, and simultaneously has the laser protection function, so that the method has important significance for overall weight reduction and protection.