63 results about "Stiffness design" patented technology

The invention discloses a multi-scale variable stiffness optimization design method for a three-dimensional fiber reinforced composite material, relates to the field of variable stiffness design of fiber reinforced composite materials, and establishes a multi-scale variable stiffness optimization design framework for the three-dimensional fiber reinforced composite material. The analysis sensitivity of a macroscopic structure topology design variable and a microcosmic fiber laying angle design variable to an objective function and volume constraint is deduced. The effectiveness of the method provided by the invention is verified through numerical examples, and the method provided by the invention is provided based on original calculation data, so that high adaptation of a design result and a manufacturing result is ensured to the greatest extent, and meanwhile, the method has the advantages of high adaptability and easiness in popularization.

To design an additively manufactured body that has strength equivalent to that of a desired injection-molded body. [Solution] The shape design method includes the steps of: dividing the shape of an anisotropic additive manufacturing body into an invariant region where shape changes are not permitted and a variable region where shape changes are permitted; designing the resulting variable region based on the rigidity of an injection molded body having the same shape as the anisotropic additive manufacturing body; performing structural analysis calculations using a structural analysis model of the additive manufacturing body obtained by combining the designed variable region and the invariant region; and determining whether the rigidity and strength of the additive manufacturing body obtained by the structural analysis calculations are within an acceptable range.

The application provides a machine tool space stiffness design method, device and equipment based on multi-working condition topology optimization. The method is applied to the field of machine tool optimization design. The method comprises the following steps: designing a machine tool configuration, constructing a machine tool geometric model based on the machine tool configuration, and identifying key components affecting the dynamic and static stiffness of the machine tool; taking the key components as optimization areas, constructing a multi-working condition topology analysis model and performing topology optimization to obtain topology optimization results of the key components under multi-working conditions; obtaining a mean value of the topology optimization quality by statistics; performing rib structure design and optimization according to a quality control target; checking the matching of the design quality of the optimized key components and the corresponding quality control target; if the matching meets the requirements, performing modal simulation experiments on the whole machine model to evaluate the optimized dynamic and static stiffness performance of the whole machine in space. The method can effectively guarantee that the machine tool has excellent dynamic and static stiffness in different space positions and is suitable for the research and development of high-precision machine tools.

The invention relates to the field of bridge engineering, in particular to a bridge variable stiffness distribution design method, a variable stiffness supporting system and a bridge structure. Vertical supporting and horizontal force transmission between the main beam and the lower structure are achieved through the variable-rigidity supporting system, in the variable-rigidity supporting system, vertical supporting force is only provided for the main beam through a support, and longitudinal rigidity is provided for the main beam through a variable-rigidity device; through the mode that the functions of providing longitudinal rigidity and vertical bearing capacity are designed separately, the problem that high bearing capacity and small longitudinal rigidity design and manufacturing cannot be achieved at the same time under the condition that a traditional single bridge support needs to meet the bearing capacity requirement and also needs to have the horizontal force transmission function is solved. By means of the variable-rigidity supporting system, according to different pier column heights and different pier column rigidities, reasonable distribution of constraint rigidities of pier columns at different height positions can be achieved by conducting customized design on structural parameters of the corrugated steel pipe, the internal force of a pier is adjusted, and the design economy is improved.

The present invention relates to the field of aerospace engineering technology, and in particular to an aircraft structure inverse design method based on structural dynamic characteristics. The aircraft structure inverse design method based on structural dynamic characteristics first finds an aircraft similar to the design target aircraft based on the known aircraft appearance and function. Then, according to the similarity relationship, the basic structure of the load-bearing parts of the design target aircraft, as well as the mass ratio and distribution position of each part such as the structure, load, and fuel are given. By adjusting the cross-sectional form and material density, a finite element model of the relevant structure is established, and then the inverse design structure of the aircraft is finally determined through calculation and iteration. The inverse design method gives priority to satisfying structural dynamic similarity, is easier to satisfy and converge in terms of the mass and stiffness design of the structure, reduces the number of iterative designs, and requires less aircraft design experience. Therefore, it has advantages in the inverse design process of those who lack aircraft design experience or in some new aircraft.

The method, apparatus, equipment, and readable storage medium for determining the local stiffness of the subframe are as follows: First, the KC characteristic design target of the target suspension is obtained, and the overall stiffness design requirements of the suspension system to ensure that the KC characteristics meet the target are determined. Then, a suspension rigid body simulation model is constructed to shield the stiffness deformation effects of the suspension links, steering knuckles, and non-bushing components of the subframe. The bushing stiffness parameters at each connection position of the suspension are decoupled and locked with the KC characteristic design target as a constraint. Then, based on the stiffness series equivalence relationship, the local stiffness at the connection position between the subframe and the suspension links is equivalent to an equivalent elastic element connected in series on the suspension force transmission path. With the overall stiffness design requirements of the suspension system as a constraint, the initial target value of the local stiffness of the subframe is obtained by inverse solution in combination with the locked bushing stiffness parameters. Finally, a suspension simulation model including the equivalent subframe stiffness is constructed. Through KC characteristic simulation verification and iterative correction under the target working condition, the final target value of the local stiffness of the subframe is locked.

The application provides a double-scale optimization design method of a multi-configuration lattice structure, which adopts a topology optimization based on a variable volume rate method and an integer programming model based on a digital coding unit library in macro and micro scales respectively, and adopts an RBF neural network to connect the macro and micro optimization problems; the macro determines the optimal volume rate of each unit in the lattice structure so as to minimize the overall structure flexibility, and the micro determines the optimal configuration of each unit so as to minimize the unit strain energy. The multi-configuration lattice obtained through the optimization design has significant advantages, compared with the traditional single-configuration lattice structure, and can ensure that a lower flexibility and a larger stiffness design result is obtained under the same material consumption, and meanwhile, the multi-configuration lattice unit can effectively adapt to the stress state of different regions in the macro structure and effectively reduce the stress concentration phenomenon. The method is suitable for any load working condition, and can realize the performance requirements of light weight, high strength, uniform stress and convenience for 3D printing of the lattice structure.

The invention relates to a design method of a variable stiffness composite shock absorber based on temperature control, which comprises the following steps of: 1, carrying out microscopic variable stiffness design on a raw material for preparing a shape memory alloy spring to generate a shape memory effect; 2, microcosmic variable stiffness design of the shape memory alloy micro-spring is carried out, wherein the design comprises the steps of determining the maximum shear strain, determining the shear strain in a high-temperature austenite state, determining the shear stress in the high-temperature austenite state and determining the spring wire diameter and the spring diameter of the shape memory alloy spring; 3, macroscopic variable stiffness design of the composite shock absorber is carried out; the method comprises the following steps: firstly, adhering the micro-spring designed in the step 2 and damping rubber in a mold through a vulcanization process to form a composite damping body; and then the composite vibration reduction body is solidified between the upper pressing plate and the base plate through gluing, and the resistor disc is fixedly connected to the base. According to the invention, the rigidity of the shock absorber is changed in three dimensions by utilizing the shape memory effect of the shape memory alloy under the action of temperature, so that the variable-rigidity shock absorption requirement of a hemispherical resonator gyroscope inertial navigation system is met.

The application discloses a rigidity design method of a self-standing reinforced steel chimney, and belongs to the technical field of structural engineering. Firstly, according to the chimney size of the preliminary design and the basic wind pressure value of the design, the standard value of the along-wind load and the equivalent static load of the transverse-wind vortex-induced resonance are respectively calculated, and based on the virtual work principle of structural mechanics, a theoretical solution of the top horizontal displacement of the chimney is obtained. Secondly, considering the influence of the deformation characteristics of the chimney shell and the like, the theoretical solution is multiplied by a maximum horizontal displacement correction coefficient to obtain a real value of the maximum absolute value of the horizontal displacement of the top of the chimney cylinder. Finally, whether the real value of the horizontal displacement exceeds the limit value of the specification is checked to determine whether the chimney wall thickness needs to be increased to improve the rigidity. The application is accurate and reliable, simple to calculate, can save the building materials as much as possible under the premise of ensuring the reliable rigidity of the chimney cylinder structure, and is helpful to obtain a reasonable and reliable rigidity design scheme of the self-standing reinforced steel chimney under the combined action of the along-wind load and the transverse-wind load.

The application discloses a kind of rigidity optimization methods of double-motor coaxial driving system and related equipment, it is related to motor coaxial driving system field.The application includes: obtaining the structure parameters and motion parameters of double-motor coaxial driving system, establishing the three-degree-of-freedom torsional dynamics model between double-motor end and load end, equivalent transmission mechanism as multiple connection stiffness and damping, and on this basis, the optimization objective function with load end tracking error and structure internal force index as target is constructed, and the stiffness of transmission mechanism is optimized and solved under the stiffness constraint condition.Sample set is constructed based on dynamics simulation and optimization result, and stiffness prediction model is trained, and the transmission mechanism stiffness configuration result of matching working condition is quickly output according to current structure parameters and motion parameters during actual operation of system.The application reduces the dependence of transmission mechanism stiffness design on experience and repeated test, and improves the dynamic performance and positioning accuracy of double-motor coaxial driving system.

The invention provides a torsion damper rigidity design method and device, electronic equipment and a storage medium, and the method comprises the steps: testing the vibration damping characteristics of a torsion damper under different working conditions based on a torsion damper rigidity analysis model; according to the damping characteristics of the torsion damper under different working conditions, the influence degree of different parameters on the attenuation rate of the torsion damper is determined through an orthogonal test method; target parameters are optimized according to the influence degrees of different parameters on the attenuation rate of the torsion damper, the target parameters are the first n parameters with the influence degrees ranked from large to small, and n is larger than or equal to 1. In the embodiment of the invention, the target parameters are analyzed and optimized through the torsion damper rigidity analysis model, so that the design of the rigidity of the torsion damper is completed in the development process of the hybrid gearbox, and in the later calibration stage of a project, the method provided by the embodiment of the invention still can be used for optimizing the rigidity of the torsion damper, so that the reliability of the hybrid gearbox is improved. Therefore, an important reference basis is provided for early-stage NVH development and later-stage NVH calibration of the hybrid gearbox.

The invention provides a composite high-order quasi-zero stiffness vibration isolator and an optimization method thereof, and belongs to the field of vibration isolators. The problems that a traditional quasi-zero-stiffness vibration isolator is prone to exceeding a low-stiffness displacement interval under the conditions of low damping and large excitation, dynamic stiffness is sharply increased, resonant frequency drifts and frequency jumps are caused, and the engineering applicability of the quasi-zero-stiffness vibration isolator is seriously limited are solved. A vibration isolation system with a nonlinear rigidity coupling characteristic is constructed by integrating a positive-rigidity supporting spring, a negative-rigidity mechanism and an electromagnetic vibration isolation mechanism. Analysis shows that the high-order quasi-zero stiffness design eliminates the low-order stiffness item through the specific parameter design, expands the quasi-zero stiffness displacement range, and reduces the dynamic stiffness of the system, so that the initial vibration isolation frequency is significantly shifted to a lower frequency, and the formant is well inhibited; the accuracy of the model is verified through numerical simulation and a harmonic balance method, and the advantages of the high-order quasi-zero stiffness system in the aspects of resonance peak suppression and vibration isolation bandwidth widening are proved.

The present invention discloses a three-pivot engine compact main load-bearing structure stiffness design method and application. When the method is implemented: first, the determined rotor structure support stiffness is iteratively optimized and designed to determine the stiffness of each support; second, the static strength and each support stiffness of the initial stator assembly are analyzed. If the static strength and support stiffness requirements are not met, the stator assembly is optimized, and the stator assembly structure determined for the first time is obtained after optimization; then, the coaxiality of each support of the stator assembly determined for the first time is analyzed. If the requirements are not met, the main load-bearing structure is optimized, and the stator assembly structure determined again is obtained after optimization; finally, the static strength and support stiffness of the stator assembly determined again are analyzed. If the requirements are met, the final stator assembly structure is obtained, otherwise iterative optimization is performed. The present invention can significantly improve the vibration performance and structural reliability of the whole machine, and is suitable for the engineering design of aircraft engines and gas turbines.

This invention provides a floor vibration damping structure and a rail vehicle. Multiple through holes are spaced apart along the floor's extension direction in the vibration damping body. Each through hole has a first inner wall and a second inner wall arranged opposite to each other along the expansion and contraction direction of the vibration damping body. The first and second inner walls have a separated state and an abutting state. In the separated state, the vibration damping body provides a first elastic force to the floor. When the vibration damping body is subjected to increased pressure, the first and second inner walls are in the abutting state, and the vibration damping body provides a second elastic force to the floor. By designing the vibration damping body with holes, a high-stiffness elastic body with low stiffness design is achieved, which is beneficial for reducing in-vehicle noise. It also achieves a variable stiffness design; that is, when the hole is compressed, it provides low-stiffness vibration damping support. When subjected to a large external load or passenger jumping impact load, the first and second inner walls are in the abutting state, the hole closes, and high-stiffness support is achieved, preventing excessive floor subsidence that could lead to floor damage. This improves vibration damping efficiency while satisfying lateral support stability.

The invention relates to a rotor system integrated topological optimization design method considering dynamic performance, and belongs to the technical field of high-performance calculation science, and the method comprises the following steps: taking statics and rotor dynamics as constraint conditions for a rotor two-dimensional structure, carrying out two-dimensional topological optimization design, and obtaining a new rotor two-dimensional structure; and on the basis of the new two-dimensional structure of the rotor, three-dimensional topological optimization design is carried out on the sector model of the rotor by taking the rotation period structure frequency and the statics property as constraint conditions, and a new three-dimensional configuration is obtained. According to the method, on the basis of traditional topological optimization which only considers the static performance, the constraint on the dynamic performance is increased, the dynamic performance requirement needed by the rotor system can be met while the maximum rigidity design is completed, the design period can be effectively shortened, and the design efficiency can be effectively improved.

The application belongs to the technical field of hybrid magnetic bearing, and discloses a synchronous shifting electro-permanent magnetic composite thrust bearing and a quasi-zero stiffness design method in any interval of the synchronous shifting electro-permanent magnetic composite thrust bearing. The synchronous shifting electro-permanent magnetic composite thrust bearing is proposed, and the follow-up regulation and control of the air gap thickness between the electromagnetic bearing coil and the thrust disc can be realized through closed-loop control, so that the problem of the mismatch between the rotor shifting amount allowed by the permanent magnetic bearing and the rotor shifting amount allowed by the electromagnetic bearing is solved, and the synchronous shifting electro-permanent magnetic composite thrust bearing has technical advantages of low operation power consumption, complete suspension in the bearing direction, low risk of fatigue failure and wear of parts in actual application. Further, a quasi-zero stiffness design method in any interval of the synchronous shifting electro-permanent magnetic composite thrust bearing is proposed, and two control modes based on current control and air gap control are given, so that the quasi-zero stiffness design in any interval can be realized, thereby improving the longitudinal vibration reduction and isolation performance. The method is simple to operate and has high control precision in actual application.

The invention discloses a double-layer staggered truss structure with bidirectional lateral stiffness, and relates to the technical field of truss structures, the double-layer staggered truss structure comprises truss seats, the truss seats are symmetrically arranged, a plurality of supporting beams are fixedly connected to the surface of the top end of each truss seat, and transverse beams are fixedly connected to the top ends of the supporting beams; the top ends of the transverse beams are fixedly connected with top beams, the top beams are in an arc shape, and the opposite sides of the top beams are fixedly connected with connecting beams. The bidirectional balanced lateral stiffness is achieved, load impact from different directions can be effectively resisted, an efficient force transmission path is constructed through the synergistic effect of the arc-shaped top beam and the inhaul cable system, it is ensured that loads are evenly dispersed to the whole structural system, and then the mechanical linkage principle is adopted, so that the mechanical linkage effect is achieved. Automatic adjustment can be achieved without external energy input, the reliability and practicability of the structure are greatly improved, and therefore the bidirectional lateral stiffness design is achieved, and excellent stability guarantee is provided for a building structure.

This invention discloses a quantitative design method for the stiffness of an airfoil tooling flag, comprising: Step 1, establishing a three-dimensional geometric model of the tooling flag, and obtaining a simplified model of the airfoil tooling flag by simplifying the three-dimensional geometric model; Step 2, setting mechanical boundary conditions for the simplified model of the airfoil tooling flag; Step 3, establishing constraint equations based on the simplified model of the airfoil tooling flag and the location of the load application points in the model; Step 4, solving for the displacement field results of the simplified model of the airfoil tooling flag under the concentrated load by applying a concentrated load based on the load application points of the simplified model of the tooling flag; Step 5, meshing the simplified model of the tooling flag and post-processing the data of the mesh elements, including: using the displacement field results obtained in Step 4 and the mesh elements divided by the simplified model of the airfoil tooling flag to obtain the displacement matrix and total mass of the simplified model of the airfoil tooling flag; Step 6, calculating the optimal tooling flag design scheme that meets the stiffness index requirements by combining the structural parameters in the simplified model of the airfoil tooling flag and using the calculation method in Step 5. The technical solution provided by this invention selects the optimal parameter scheme in the design based on the calculation results, reduces the weight of the tooling flag while ensuring the stiffness of the tooling flag, avoids structural deformation caused by insufficient stiffness of the tooling flag, and the proposed quantitative stiffness design method can provide a theoretical basis for optimization design, which is a fast and effective design method.

This invention provides a design method, device, equipment, and medium for pile groups of unequal lengths on steep slopes, relating to the field of pile foundation design technology. The method includes: calculating the stiffness of the embedded pile section based on the vertical compressive stiffness of a single pile on flat ground, taking into account the parameters of the pile foundation structure and soil layer parameters on the slope; deriving a vertical stiffness model for a single pile on the slope based on the pile foundation structure, the length of the free section pile, and the stiffness of the embedded pile section; calculating the length of the free section pile based on the vertical stiffness model of the single pile on the slope and the slope topographic parameters, thus constructing a vertical stiffness model for the pile group on the slope; establishing the vertical stiffness model of the pile group on the slope and the expression for the design of the pile group with equal stiffness based on the spatial relationship between the slope and the pile foundation and the principle of equal stiffness, thus obtaining a basic model for the equal stiffness design method; calculating the length of the embedded pile section in the pile group based on the basic model of the equal stiffness design method, and constructing a pile group design scheme by combining the length of the embedded pile section and the length of the free section pile. This invention solves the problem of uneven stress and settlement in pile group foundations on slopes.

The invention belongs to the technical field of aircraft strength and rigidity design, and particularly relates to a shear deformation component calculation method of a rectangular sandwich panel with four simply supported sides under normal force. The method includes the following steps that firstly, a coordinate system is defined based on the four-side simply-supported rectangular sandwich panel; 2, defining shearing parameters of the four-side simply-supported rectangular sandwich panel structure; 3, establishing an infinitesimal body balance equation; 4, establishing a control equation according to the infinitesimal Hooke's law; and 5, solving the shear deformation.

The application discloses a three-dimensional fiber-reinforced composite material multi-scale variable stiffness optimization design method, relates to the field of fiber-reinforced composite material variable stiffness design, and establishes a three-dimensional fiber-reinforced composite material multi-scale variable stiffness optimization design framework, and deduces the analytical sensitivity of macrostructure topological design variables and micro-fiber laying angle design variables to an objective function and a volume constraint. Through a numerical example, the effectiveness of the method proposed in the application is verified, the method is proposed based on original calculation data, the highly adaptive design result and the manufacturing result are maximally ensured, and the method has the advantages of strong adaptability and easy popularization.

The application provides a curved track bed, which comprises a curved plate body, a plurality of track bottom pads and a plurality of vibration isolators embedded in the curved plate body. Since the curved plate body is placed on the base through the vibration isolators containing elastic elements, a floating plate form is formed, the rigid connection between the track structure and the base structure is cut off, and the track bottom pads are further arranged, so that the impact energy during train running can be absorbed through the plurality of elastic elements and the track bottom pads, and the track vibration reduction and noise reduction effect at the turning track can be realized. Further, the elastic element arranged on the outer strand of the track has relatively lower rigidity, and the track bottom pad has a variable rigidity design, one side of which with higher rigidity faces the outer side of the track. Therefore, the curved track bed of the application has a targeted design, which can not only reduce vibration and noise, but also correct the deviation of the curved steel rail, better balance the stress conditions of the wheels on both sides of the train when passing the curve, thereby improving the curve passing efficiency, and improving the service life, safety and reliability of the related facilities.

The present invention belongs to the field of automobile technology, specifically a method, device, equipment and storage medium for designing the stiffness characteristics of a diaphragm air spring. It comprises: step one, CAE analysis of the axial stiffness of the diaphragm air spring; step two, designing the radial dimension parameters of the cross section of the diaphragm air spring; step three, designing the axial dimension parameters of the cross section of the diaphragm air spring; step four, designing the performance parameters of the diaphragm air spring. The present invention adopts a method based on sensitivity analysis to achieve the design of a model air spring by optimizing the structure and performance parameters of the air spring; the present invention can achieve the coordination of the structural design and stiffness design of the diaphragm air spring, improve the design efficiency, ensure the design accuracy, and solve the problem that the air spring designed based on the stiffness theory formula cannot guarantee the stiffness design accuracy, and a large number of experiments are required to improve the stiffness design accuracy, the design cycle is long, and the design efficiency is low.

This invention provides an adjustable stiffness wind-resistant bearing, relating to the technical field of wind-resistant bearings. The adjustable stiffness wind-resistant bearing includes a left side plate, a spherical cap liner, an intermediate body, a helical height adjustment component, a right side plate, and a counterweight assembly. The plane of the spherical cap liner is connected to the left side plate, and the spherical surface of the spherical cap liner is connected to the intermediate body. The intermediate body is provided with a slide rail and a male helical surface. The helical height adjustment component is provided with a female helical surface, and the male helical surface is adapted to the female helical surface. The right side plate is provided with a slide groove, which is adapted to and connected to the slide rail. The counterweight assembly includes a wire rope, a counterweight tray, and a counterweight block. One end of the wire rope is connected to the helical height adjustment component, and the other end is connected to the counterweight tray, passing through the right side plate. The counterweight block is installed on the counterweight tray. This adjustable stiffness wind-resistant bearing solves the technical problems of existing wind-resistant bearings, such as non-adjustable compressive stiffness, limited compressive stiffness design range, and the elastic element being in a compressed state for a long time, leading to easy elastic failure.

The invention provides a machine tool space stiffness design method, device and equipment based on multi-working-condition topological optimization, the method is applied to the field of machine tool optimization design, and the method comprises the following steps: designing a machine tool configuration, constructing a machine tool geometric model based on the machine tool configuration, and identifying key components influencing the dynamic and static stiffness of a machine tool; taking the key components as optimization areas, constructing a multi-working-condition topology analysis model and carrying out topology optimization to obtain topology optimization results of the key components under multiple working conditions; performing statistics to obtain a topological optimization quality mean value; designing and optimizing a rib plate structure on the basis of a quality control target; checking the matching between the design quality of the optimized key component and the corresponding quality control target; and if the matching performance meets the requirement, performing a modal simulation experiment on the whole machine model to evaluate the space dynamic and static stiffness performance of the optimized whole machine. According to the method, it can be effectively guaranteed that the machine tool has excellent dynamic and static rigidity in different spatial positions, and the method is suitable for research and development of high-precision machine tools.

The utility model discloses a long-stroke side bearing of a railway vehicle, and relates to the technical field of train side bearings. Comprising a side bearing seat, U-shaped grooves are formed in the two sides of the upper wall face of the side bearing seat, and rolling shafts are rotationally connected into the U-shaped grooves. The train side bearing suitable for being used for a long distance is designed, the side bearing seat is made of high-strength forged steel and connected with a bogie, when a train body rolls laterally, the upper side bearing body inclines relative to the side bearing seat, the rubber pad and the springs provide elastic restoring force, the hydraulic damper generates damping force and restrains vibration, and the long-stroke design allows a larger train body side rolling angle. The curve trafficability is improved; the low-rigidity design reduces the vibration of the vehicle body and improves the comfort; the service life is prolonged and the maintenance is reduced by the high-wear-resistant material. The device has the advantages that curve passing capacity is improved, complex lines are adapted, rigidity is low, vehicle body vibration is reduced, riding comfort is improved, abrasion resistance is high, the service life is prolonged, maintenance cost is reduced, installation and maintenance are easy, and reliability is high.

A method for determining winding parameters of a pressure vessel, comprising: obtaining stress functions, strain functions and displacement functions of all plies based on a pressure vessel mechanics model and boundary conditions; obtaining a relationship between a failure factor, a radial deformation amount, a number of layers and a fiber angle of each layer based on the stress functions, the strain functions, the displacement functions of the plies and a strength failure criterion of the pressure vessel; and determining the fiber angle of each layer by an optimization algorithm based on the relationship between the failure factor, the radial deformation amount, the number of layers and the fiber angle of each layer. The present disclosure obtains one or more groups of optimal fiber angles through the optimization algorithm, and can obtain corresponding fiber angles under the minimum number of layers by adjusting the given number of layers while keeping the failure factor and the radial deformation amount meeting the requirements. The direction of carbon fibers is no longer limited by 0° / ±45° / 90° or other given angles, and the optimal plating scheme in theory can be found after breaking free from the constraints, which is more beneficial to the lightweight and strength and stiffness design of the pressure vessel.

This invention discloses an M-shaped low-frequency vibration isolation structure mimicking the leg structure of an arthropod, belonging to the field of vibration isolation technology. A design method for the biomimetic M-shaped structure is proposed, utilizing components such as connecting rods, bearings, springs, and guiding devices to construct the structure. The connecting rods simulate the geometry and structure of an arthropod leg, while the springs and their components approximate the leg muscle structure. A structural stiffness design method for the biomimetic M-shaped structure is proposed, including nonlinear positive stiffness and nonlinear negative stiffness design. Utilizing the unique nonlinear positive stiffness characteristics of the biomimetic M-shaped structure, it can better adapt to negative stiffness, thus significantly widening the quasi-zero stiffness range. Furthermore, the relationship between the effective vibration isolation load and structural parameters of the biomimetic M-shaped structure is given. Finally, the quasi-zero stiffness condition of the biomimetic M-shaped structure is presented, and the results show that this structure can effectively reduce the vibration isolation initiation frequency and improve low-frequency vibration isolation performance.

The invention belongs to the field of aircraft structure design and strength analysis, and particularly relates to a titanium hybrid material three-layer damage safety lug reliability calculation and analysis method which combines a rigidity design criterion and a damage tolerance analysis method of a multi-force transmission path lug structure on the theoretical basis of a load sharing parallel system. A load sharing principle and a life equivalence principle are determined, and a basis is provided for life equivalent conversion. For a multi-force-transmission-path lug structure, the reliable working condition of the lug structure can be divided into three layers of unfailed lugs, one layer of failed lugs and two layers of failed lugs, the reliability of the lug structure is the sum of the occurrence probabilities of the three conditions, and the calculation method is elaborated in detail.

The present invention relates to the field of aero-engine technology, and discloses a high-temperature zone threaded connection method and assembly with both anti-sticking and anti-rotation and anti-retreat functions. The tail of a D-head bolt has a tapered load-balancing hole axially extending from the tail of the D-head bolt to the middle of the bolt, thereby satisfying the variable stiffness design of the bolt shank and ensuring that the threads are more evenly stressed during operation. In particular, the method avoids the problem of thread stress during mating of internal and external threads, where the thread stress decreases sequentially from the head to the tail of the bolt, with the first few threads bearing approximately 70% of the load. The large extrusion load on the threads causes deformation and sticking of the threads, excessive friction between the threads, and difficulty in thread adhesion and nut disassembly. Drain plates are added to the rotor shafts corresponding to the tail and head of the D-head bolt, and the airflow outlet of the airflow cooling hole corresponding to each D-head bolt is located between the two drain plates. This avoids the problem of bolt adhesion caused by excessive temperature rise at the bolt connection due to wind resistance.