102 results about "Strength design" patented technology

The invention discloses a cargo floor structural strength design optimization method and system based on load prediction, and belongs to the technical field of freight vehicle structural design. The maximum equivalent stress of each node in a floor grid area is calculated and normalized by constructing a load prediction model of the dynamic distribution state of cargoes in a cargo tank; forming a stress intensity coefficient matrix; identifying a high-risk area and constructing a reinforced target area set; obtaining an initial parameter of the bottom plate structure, establishing a finite element model, and setting an adjustable structure parameter in the target area; a candidate structure design scheme set is generated, simulation calculation is executed, the total structure mass, the maximum stress value and the first-order inherent frequency of each scheme are extracted, and a performance evaluation vector is formed; selecting an optimal design scheme through a multi-objective optimization algorithm, and outputting structural parameters of the optimal design scheme as a final design result; according to the method, the structural optimization design of the cargo tank bottom plate under the complex load working condition is achieved, and the method has high engineering adaptability and practical value.

The invention relates to the technical field of equal-strength design, and provides a high-reliability equal-strength design method and system for an intelligent cubic press, which considers structural characteristics of the cubic press, performs physical field analysis, modeling and simulation, determines deformation, temperature, stress distribution and stress concentration areas of key components, predicts structural crack initiation of the key components, and provides a high-reliability equal-strength design method and system for an intelligent cubic press. Crack propagation simulation is carried out; establishing a fatigue strength life prediction model based on deep learning and a simulation data set; constructing a fatigue strength reliability model, and establishing a mathematical association relationship among fatigue life, fatigue damage and reliability; a reliability calculation index is introduced into multi-objective optimization of the structure, a high-precision numerical solution of reliability robustness optimization design based on structure simulation is developed, and equal-strength design of the cubic press is achieved. According to the method, the optimal combination of design parameters can be obtained, the equal-strength design of parts and the whole machine structure is formed, and development of intelligent, high-precision and large-scale cubic press equipment is promoted.

The present application belongs to the field of helicopter rotor system strength design, and particularly relates to a structural characteristic stress optimization calculation method under multi-load different phase loading. The periodic load containing exact phase information is divided into analysis steps containing certain time interval points, a numerical fitting method is used to find the maximum stress of the structure in the period, and then the structural characteristic stress is obtained. The method can quickly and accurately extract the structural characteristic stress, avoid the phenomenon that the characteristic stress is too small due to unreasonable step setting, and has important significance for the strength design of the helicopter rotor system. Compared with the traditional different phase load loading, the method of loading all load maximums, the analysis is more accurate, and the stress change of the structure in the load loading period can be effectively simulated.

The invention discloses a turbine blade probability strength design optimization method and device, equipment, a medium and a product, and relates to the technical field of blade strength design, the method comprises the following steps: obtaining a preliminary blade geometric structure and preliminarily selecting material parameters according to strength requirements and operation load working conditions; the probability distribution of the load working condition, the geometric structure, the material parameters and the model parameters serves as input variables of finite elements, and stress-strain response is obtained; designing a similar structural member, carrying out multi-level verification on the precision of the life prediction model, calculating the total damage of the blade based on the life prediction model, obtaining the probability distribution of the total damage, and further obtaining the reliability under the design life meeting the strength requirement; and judging whether the reliability meets design requirements or not, and if not, performing optimization design by taking improvement of a reliability value as a target until the reliability meets the design requirements. The objective uncertainty in the design process can be considered, the part service life prediction precision is improved, and more accurate strength design is achieved.

The present application relates to the technical field of high-temperature structural component fatigue strength design and life assessment, and particularly relates to a low-cycle multi-axial fatigue life prediction method based on powder high-temperature alloy damage mechanism. The method comprises: for the dangerous point of the component under non-isothermal multi-axial cyclic loading, calculating pure fatigue damage, pure creep damage and fatigue-creep interaction damage caused by a single load cycle; accumulating the pure fatigue damage, the pure creep damage and the fatigue-creep interaction damage to obtain the total damage of the single load cycle; taking the inverse of the total damage to predict the total failure life of the component under non-isothermal multi-axial cyclic loading. The method of the present application realizes effective prediction of the low-cycle multi-axial fatigue life of the powder high-temperature alloy component by accurately decomposing the damage of the dangerous point under non-isothermal multi-axial cyclic loading, can more truly reflect the comprehensive prediction model of the failure physics of the powder high-temperature alloy under multi-axial thermal mechanical loading, and improves the accuracy and reliability of the life assessment.

The present application belongs to the technical field of structural strength analysis, and particularly relates to a strength analysis method for a variable gradient composite material wall panel, the strength analysis method comprising: solving the shear stress and compression stress of the variable gradient composite material wall panel based on the external load and structural parameters of the variable gradient composite material wall panel; calculating the allowable shear stress, allowable axial compression stress, and allowable bending stress based on the structural parameters; calculating the safety margin through the shear stress, the compression stress, the allowable shear stress, the allowable axial compression stress, and the allowable bending stress; the iterative safety margin is 0; and the stability strength design of the trapezoidal composite material wall panel with a variable gradient of the rudder surface can be performed, and finally the lightest wall panel structural parameters that meet the constraint conditions are obtained.

The present invention relates to a design method for a novel cryogenic liquid hydrogen storage tank, and belongs to the field of liquid hydrogen storage technology. The design method for the novel cryogenic liquid hydrogen storage tank includes: completing the strength design of the storage tank, including calculating the thickness of the wall panels, top panels, and bottom panels of the inner tank and the outer tank; completing the cold insulation design of the storage tank, including calculating the heat transfer of the top panel, wall panels, and bottom panel of the storage tank to calculate the evaporation rate of the storage tank, and adjusting the relevant parameters of the liquid nitrogen cold screen according to the requirements for the evaporation rate of the storage tank. The present invention is aimed at a large-scale vertical cryogenic liquid hydrogen storage tank that adopts a liquid nitrogen cold screen structure and a dome design for the first time, and innovatively completes the strength design and cold insulation design of the storage tank.

The application belongs to the field of structural strength design, and relates to a helicopter metal moving part high-cycle fatigue damage evolution method considering load sequence. The method comprises the following steps: according to a high-cycle fatigue damage model considering stress ratio and load sequence effect, based on finite element theory, evaluating a high-cycle fatigue damage evolution process of a helicopter rotor metal structure under variable amplitude loading, and predicting a high-cycle fatigue life.

The application belongs to the technical field of structural strength design, and discloses a helicopter blade pin fatigue life evaluation method considering folding and tethering overload, and the steps are as follows: step one, evaluating the blade pin load and fatigue damage under the folding state of the blade; step two, evaluating the blade pin load and fatigue damage under the tethering overload; and step three, evaluating the blade pin fatigue life under the folding state superimposed with the tethering overload.

The invention provides a strength design method of a large non-uniform reinforced cylindrical shell pressure-resistant structure. The strength design method comprises the following steps: (1) carrying out stress analysis on a reinforced cylindrical shell structure which externally bears hydrostatic pressure; (2) constructing a cylindrical shell deflection curve expression containing unknown parameters based on an elastic foundation beam theory; and (3) solving unknown parameters in a cylindrical shell deflection expression according to boundary conditions of reinforcing ribs of each section of cylindrical shell to obtain a calculation formula of a cylindrical shell deflection curve, and performing strength calculation on the non-uniform reinforced cylindrical shell pressure-resistant structure in combination with actual material parameters and structure parameters. The method is reasonable in conception, breaks through limitation of a traditional method, is wider in application range compared with a traditional theoretical method, can conveniently and quickly perform strength design on the non-uniform reinforced cylindrical shell structure, and is suitable for popularization and application.

The application belongs to the field of aircraft structure dynamic strength design, and particularly relates to a dynamic load static equivalent coefficient determination method and a structure parameter design method, which comprises the following steps: S1: according to a water ditching dynamic load measurement test, a relationship curve between a water pressure load of a bottom of an aircraft fuselage and a time history is obtained, and a peak value Ps of the water pressure load is determined according to the relationship curve; S2: a water ditching test of an elastic model of the bottom of the fuselage is performed to determine a critical failure parameter of the elastic structure; S3: a static mechanical property test is performed with the critical failure parameter of the elastic structure to obtain a maximum static pressure Pd that can be borne by the elastic structure; and S4: a water ditching dynamic load static equivalent coefficient is calculated. The static equivalent coefficient of the water ditching water pressure dynamic load is obtained through a scale model test. The application aims to solve the problem of lacking of design load in aircraft water ditching performance design.

The invention relates to a design method and device for a metal sealing structure of an underwater wellhead connector, a medium and equipment, and the method comprises the steps that S1, under the pre-tightening working condition, mechanical analysis is conducted on a driving piston, a locking block, a Christmas tree body and a metal sealing ring; s2, under the operation working condition, mechanical analysis is conducted on the wellhead connector body and the metal sealing ring; s3, according to the steps S1 and S2, obtaining a theoretical relationship between the operation contact stress of the metal sealing ring and the structural parameters, the radial compression amount and the working pressure; s4, establishing a sealing design criterion of the metal sealing ring according to the step S3; s5, establishing a strength design criterion of the metal sealing ring according to the step S3; s6, establishing a finite element simulation model of the sealing performance of the underwater wellhead connector; s7, analyzing the sealing performance of the metal sealing ring according to the finite element simulation model of the sealing performance of the underwater wellhead connector; and S8, obtaining the contact stress of the sealing surface of the metal sealing ring according to the steps S4, S5 and S7.

The invention discloses a lightweight and multi-working-condition container flatcar underframe, which relates to the technical field of container flatcars and comprises a middle beam assembly, an end beam assembly, a sleeper beam assembly, a cross beam assembly and a central cross beam assembly. The central cross beam assembly is arranged in the middle of the middle beam assembly, the two end beam assemblies are symmetrically arranged at the two ends of the middle beam assembly, and the two sleeper beam assemblies are arranged on the middle beam assembly between the central cross beam assembly and the end beam assemblies. The number of the cross beam assemblies is two, and each cross beam assembly is arranged on the middle beam assembly between the central cross beam assembly and the sleeper beam assembly. Compared with an existing container flatcar underframe, the equal-strength design theory is fully utilized, the advantages of the variable cross-section box beams are reasonably utilized, the dead weight is reduced to the maximum extent on the basis that the rigidity and strength required by application are met, the weight of the underframe is controlled within 3.5 t, the vehicle load is improved under the condition of certain axle load, and the whole life cycle cost of the vehicle is reduced; and vehicle economic benefits are improved.

The invention belongs to the field of helicopter structural strength design, and relates to a seesaw type tail rotor hub fatigue test method. The method comprises the steps that test pieces of a seesaw type tail rotor hub shaft assembly and a shaft sleeve assembly are pasted and calibrated; determining a fatigue test static load and a dynamic load; the static load is centrifugal force, and the dynamic load is flapping bending moment and shimmy bending moment; determining a flapping load and a shimmy load applied to the process joint on the blade false piece through loading debugging, and determining a centrifugal force applied to the process joint on the blade false piece; and carrying out a teeterboard type tail rotor hub fatigue test. According to the seesaw type tail rotor hub fatigue test method, the seesaw type tail rotor hub fatigue test can be guided to be completed, the fatigue dangerous part and the fatigue failure mode of the seesaw type tail rotor hub are determined, and the blank in the field of seesaw type tail rotor hub fatigue test in China is filled.

The invention belongs to the technical field of airplane static strength design, and particularly relates to a skin corner connection strength determination method and device based on temperature influence. The method comprises the following steps: reading a mechanical response file under each industrial control of a structure and a node temperature field file of the structure; data in the mechanical response file and the node temperature field file are extracted, a preset butt joint part unit force array is assigned, the butt joint part unit force array is a two-dimensional array, the first dimension in the two-dimensional array is a connection part, and the second dimension at least comprises a structure parameter, a mechanical parameter, a temperature parameter and a working condition number; calculating the shearing margin of the connection part of each working condition; and the connecting part shearing margins of all the connecting parts under the multiple working conditions are sequenced, and the minimum margin value, the corresponding working condition number and the mechanical parameter are assigned to a preset minimum margin array. According to the method, the accuracy and the working efficiency of static strength calculation of the skin corner connection part under the high-temperature condition are improved.

This relates to a system and method for reverse designing the strength of multilayer materials, which allows for reverse design of multilayer materials without manufacturing test pieces of the multilayer material, and more specifically, it is possible to derive the required physical properties of the undetermined layer (p) to achieve the target strength of the multilayer material.

A finite element analysis method for a motor base relates to the technical field of mechanical structure strength analysis, fully considers various loads borne by the motor base when a speed reducer works, and performs accurate finite element calculation on stress and deformation of the motor base so as to provide technical guidance for strength design and cost reduction design of the motor base. The finite element analysis method for the motor base comprises the following steps of model establishment, analysis system creation, grid division, boundary condition application, solution calculation and calculation result analysis.

The present application relates to the technical fields of automobile chassis drive shaft universal joint, in particular to a reinforced structure universal joint cross shaft. The reinforced structure universal joint cross shaft comprises a shaft body, a shaft head and a reinforcing rib. Four shaft heads are distributed along the circumference of the shaft body; the projection of the four shaft heads along the axis of the shaft body is in the shape of a cross; the shaft head comprises a shaft neck, a first convex ring and a second convex ring; multiple reinforcing ribs are arranged between adjacent shaft heads; the length direction of the reinforcing rib is arranged around the axis of the shaft body; the surface of the reinforcing rib comprises a first curved surface; the reference cross section passes through the axis of the shaft body; the reference cross section passes through part of the reinforcing rib; in the reference cross section, the connecting line between the midpoint of the cross section line of the first curved surface and the geometric center point is the reference line; the included angle between the reference line and the axis of the shaft body is an acute angle. In this way, the problem of improving the overall strength of the cross shaft while ensuring lightweight and equal strength design of the cross shaft is solved.

The present application relates to a kind of static pressure composite pile construction methods, using static pressure composite pile construction equipment, including steel platform, blowout prevention and sealing device, static pressure pile machine, fixed anchor rod, first, steel platform is fixed on segment by fixed anchor rod, and counterforce is provided by tunnel structure;Then set blowout prevention and sealing device, finally static pressure pile machine is in position, and static pressure anchor rod pile is pressed in, and the purpose of governing tunnel continuous settlement is played.The present application can make pile head and tunnel structure form effective connection by side pile pressing, and do durability special handling, ensure stress and prevent and control long-term operation under the risk of leakage water;Through pile pressing, the purpose that original micro-disturbance grouting implementation effect is not good is solved, and pile body uses the high-strength design of steel bag concrete, can provide enough compression resistance;In construction process, special blowout prevention is set, to avoid construction process risk;Special static pressure anchor rod pile machine, adapt to the special working condition of tunnel long-distance transport.

The application belongs to the technical field of structural strength design, and particularly relates to a method and device for determining the tensile and compressive modulus of a grid structure. The method comprises the following steps: S1, determining the long diagonal size 2a and short diagonal size 2b of a grid unit, and the beam width h of the grid unit, wherein the grid unit is the smallest repeating unit of the grid structure, the grid unit is a diamond-shaped beam, and the grid structure is part of a full-aircraft structure; S2, obtaining the elastic modulus E of the material of the grid structure; and S3, determining the tensile and compressive modulus of the grid structure according to the following formula: E1=(Eh 3 aL) / (b 3 L 2 +h 2 a 2 b) and E2=(Eh 3 bL) / (a 3 L 2 +h 2 b 2 a), wherein E1 is the tensile and compressive modulus along the long diagonal, E2 is the tensile and compressive modulus along the short diagonal, and L is the side length of the grid unit. The application shortens the calculation time and improves the efficiency of the iteration and parameter optimization of the full-aircraft structure scheme.

A numerical simulation method for a super-cantilever tree-shaped column steel structure in a construction stage is characterized by comprising the following steps: a, model establishment: establishing an analysis model by using MIDAS software, b, stress simulation: combining construction stage simulation with TEKLA deepening design, and rehearsing a hoisting splicing process through finite element software to reduce the risk of high-altitude welding deformation; the calculated length of a rod piece of the tree-shaped column needs to be adjusted according to the branch supporting condition by judging whether lateral supporting exists or not, the calculated length coefficient ranges from 1.5 to 2.0 when a treetop is not supported, and the calculated length coefficient ranges from 0.7 to 1.0 when the treetop is supported; according to the embodiment of the invention, the maximum stress ratio of the whole construction stage is 0.72 and is smaller than a strength design value 1, and the structure optimization effect is remarkable. The numerical simulation method for the construction stage of the super-cantilever tree-shaped column steel structure has the advantages that the structural design is optimized, the construction quality and safety are improved, the cost is reduced, and the building performance and attractiveness are improved.

The utility model discloses a fatigue characteristic test device and system for a root section of a rotor blade, belongs to the technical field of structural strength design, and is used for solving the technical problem that the fatigue characteristic test device is poor in system stability and safety when the centrifugal force load is relatively large. The utility model relates to a rotor blade root fatigue characteristic test device which comprises a centrifugal force loading mechanism, a swing force loading mechanism and an assembly test bench. The positions of the centrifugal force loading mechanism and the swing force loading mechanism on the assembly test bench can be adjusted; the centrifugal force loading mechanism comprises a centrifugal force actuator and a lever, and the lever can amplify the force applied by the centrifugal force actuator and then apply the amplified force to the test piece. The rotor blade root section fatigue characteristic test device and system are safe and stable, and the loading capacity requirement of the device is remarkably reduced.

This invention discloses a method for calculating and verifying ductile fracture parameters of metallic materials, belonging to the field of mechanical property analysis technology for metallic materials. Initial equivalent plastic strain is obtained through tensile testing of standard test bars. Stress triaxiality is calculated using CAE static simulation, and fracture energy is calibrated through explicit dynamic necking simulation. These three sets of core parameters are directly applied to the simulation prediction of actual parts. Finally, physical experiments are conducted with unified constraint loading for calibration, forming a complete closed-loop process. This invention standardizes mesh generation, analysis step settings, and constraint loading methods, eliminating manual value selection and simulation distortion problems. Parameter calibration can be completed with only a single set of test bar experiments, and the test bar parameters can be directly transferred to complex parts. This method simplifies the experimental process, reduces R&D costs, achieves a fracture force prediction accuracy of 85%, and the fracture location is consistent with the experiment. It is applicable to ductile fracture simulation of most metallic materials and can accurately guide part structural optimization and strength design.

The present application provides a modular and reconfigurable aircraft structural strength design method, the method comprising: determining various single-purpose aircraft structural configuration design schemes according to usage requirements, calculating the equivalent structural strength design weight according to a single configuration design method; determining whether the difference in equivalent structural strength design weight under various single configuration design schemes meets a predetermined gap; when the difference in equivalent structural strength design weight of two or more configurations is within the predetermined gap, the aircraft structures of the two or more configurations can be combined for design, thereby forming a modular or reconfigurable aircraft structural overall plan; dividing common modules and dedicated modules according to overall aerodynamic layout requirements, and realizing aircraft configuration changes through rapid reorganization of common modules and dedicated modules. The method of the present application not only meets the user's usage requirements, but also can achieve the optimized structural aerodynamic layout for each mission, thereby reducing overall mission costs.

The present invention relates to a design method for hollow curb stones based on high-performance concrete, belonging to the field of curb stone design. It includes initially determining the dimensions of the hollow curb stones, calculating the flexural tensile stress generated by the hollow curb stones under lateral forces and horizontal thrusts, and obtaining the flexural strength design value by taking the larger value; taking an appropriate value as the compressive strength design value of the hollow curb stones; conducting concrete mix design; using full-scale tests or numerical simulations to check the flexural strength and compressive strength of the hollow curb stones; if the strength check passes, the design is completed; if not, the structural dimensions are determined again or the mix design is redone until the strength check passes. Based on the existing specifications for ordinary concrete curb stones, the present invention provides a design method for hollow curb stones based on high-performance concrete to fill the gap in the design method for high-performance concrete hollow curb stones, providing design reference and theoretical supplement for the successful application of high-performance concrete in hollow curb stones.

The invention belongs to the technical field of static load devices, and particularly relates to an annular tensile fixture and a test piece suitable for a fiber reinforced composite material, the annular tensile fixture comprises two D-shaped loading blocks, the two D-shaped loading blocks are in butt joint along a butt joint surface to form a disc with a cylindrical surface; the pull head is connected with the loading device; the pull head is of a double-lug structure, and each D-shaped loading block is hinged to one pull head through a round pin. The test piece is annular and is sleeved on the cylindrical surface of the disc formed by the D-shaped loading block; a scale distance section with a preset width is arranged at one position; the two pull heads respectively pull the D-shaped loading blocks, so that the two D-shaped loading blocks apply an annular tensile load to the composite material test piece. The precision of the mechanical property measured by the test device and the test piece is higher than that of a uniaxial tensile sample, and the processing and preparation process of the integral blade ring structure and the processing defects, residual stress and the like of internal composite materials can be fully simulated. And the structural strength design accuracy of the fiber reinforced composite material part is improved.

The invention belongs to the field of airplane composite material strength design, and particularly relates to a super-thick composite material lug strength performance value test piece design method and system, and the method comprises the steps: building a super-thick composite material lug strength performance value test piece design principle based on the strength data of a super-thick composite material lug; and designing a tensile strength performance value test piece, a shear strength performance value test piece and an extrusion strength performance value test piece according to a test piece finite element model and an ultra-large thickness composite material lug strength performance value test piece design principle. Through a system scheme of'finite element modeling-safety margin control-component strength design ', not only is the industry problem of strength data missing of the ultra-large-thickness composite material lug solved, but also the reliability of test piece design, the accuracy of strength data and the high efficiency of design guidance are ensured through scientific parameter association and failure mode control, and the method is suitable for large-scale popularization and application. And a key technical support is provided for engineering application of the ultra-large-thickness composite lug for the main force bearing component.

The invention discloses a fatigue strength analysis method based on opposite-pulling angle box studs. Calculating the working stress of the dangerous section of the stud of the opposite-pulling angle box under each working condition; calculating a detail fatigue rated value DFR of a key structure of the dangerous section of the stud; the maximum allowable working stress is converted through the DFR; and calculating the fatigue margin MS of the dangerous section of the stud of the opposite-pulling angle box, and when the fatigue margin MS is greater than 0, determining that the dangerous section of the stud meets the fatigue strength design requirement. According to the method, the DFR estimation precision of the corner box stud is improved, and the reliability and credibility of structural safe life design are improved.

The invention belongs to the technical field of aircraft body strength design, and particularly relates to a tension-shear separation design method for a uniaxial load bearing connector and the load connector. On the basis of a given uniaxial load and a fixed supporting surface of a machine body structure, a load transfer path for separately transferring a shear load and a tensile load is provided, and a boss / groove is arranged on a joint bottom plate to be precisely matched with the machine body structure and is used for transferring the load in a mounting plane; meanwhile, the bolt hole is expanded to prevent the hole wall from being in contact with the bolt, and the bolt only transmits the load perpendicular to the mounting plane. Therefore, a uniaxial load borne by the joint lug is decomposed into a shear load transferred by the boss / groove of the joint bottom plate and a tensile load borne by the bolt, load separation is realized, and the design of the joint and a machine body structure is optimized.

The invention provides a low-matching butt joint shape design method and device based on equal stretch-bending composite bearing, and belongs to the technical field of welding structure design. The method comprises the steps that the stretch-bending load ratio is determined; determining the yield strength matching ratio of the weld joint to the base metal; calculating a minimum reinforcement curve of a weld zone, and distinguishing whether a structure end is subjected to rotation constraint or not; calculating the minimum weld width of a weld joint, and distinguishing structural end constraint forms; determining the radius of a transition arc at a weld toe by adopting a three-circle tangency method; determining the total weld width of the weld; and according to the minimum excess weld metal curve and the total weld width, the shape of the weld joint and geometric parameter values thereof are obtained. The low-matching butt joint shape design method based on equal-stretch-bending composite load is specifically applied to equal-load design of the low-matching butt joint under the action of the stretch-bending composite load, and is suitable for structural strength design of a welding joint.