120 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 utility model discloses a reinforced node of a crossed concrete filled steel tubular column for a cooling tower based on equal strength design, the reinforced node comprises four steel pillars, a radial reinforcing plate and a reinforcing ring, the four steel pillars are welded to form the crossed steel tubular node of an X-shaped structure, the middle position of the crossed steel tubular node is provided with a round-end-shaped steel tube outer package, and the steel tube outer package is connected with the reinforcing ring. More than three reinforcing rings are uniformly arranged in the round-end-shaped outer steel pipe along the height direction, a radial reinforcing plate is arranged at the middle position in the round-end-shaped outer steel pipe, each reinforcing ring is respectively welded with the radial reinforcing plate, and concrete is filled in the four steel supporting columns and the round-end-shaped steel pipe. According to the reinforcing joint type, the cross section is the same and the strength is equal in the height direction in the crossed area, the reinforcing joint is not provided with stiffening ribs in the steel pipe, the situation that a plurality of welding seams intersect with one another is avoided, the construction process is simplified, and manufacturing is easy.

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 sludge bin design and optimization method based on finite element analysis. The method comprises the steps that 1, a three-dimensional model of a sludge bin is established; 2, material characteristic values are added into the three-dimensional model of the sludge stock bin, and grid division is carried out; 3, after boundary strip constraint conditions and loads are added into the three-dimensional model of the sludge bin, finite element analysis software is operated, and a strength analysis result is obtained; 4, judging whether the strength analysis result meets the strength design requirement or not; if the strength analysis result does not meet the strength design requirement, returning to the step 1; if the strength analysis result meets the strength design requirement, entering the step 5; 5, carrying out optimization design to obtain an optimization design result; and 6, judging whether the optimization design result is optimal and meets the strength design requirement or not, if so, outputting the optimal three-dimensional model of the sludge bin, and if not, repeating the steps 1-5. According to the invention, the stress condition of the discharge bin under the target load can be accurately simulated, and the structure is optimized.

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 invention relates to a geometric parameter optimization design method for a large-overlap-ratio gear, and belongs to the field of vehicle transmission design. According to the technical scheme, the geometric parameter optimization design method for the large-overlap-ratio gear comprises the following steps that S1, initial parameters of a gear pair are determined according to the speed ratio requirement and the center distance; s2, dense tooth optimization is carried out according to the tooth root strengthening effect; s3, the addendum circle is determined according to the requirement of the sliding rate # imgabs0 #; s4, distributing tooth thickness according to fatigue life and backlash requirements; s5, determining a dedendum circle according to a top clearance requirement; and S6, performing tooth root transition curve optimization and hob design according to the re-determined gear parameters, and performing hobbing simulation verification. According to the scheme, gear tooth high-strength design and dense tooth optimization are achieved through a tooth root transition curve optimization method, the meshing efficiency and the transmission stability are further considered, the tooth height is controlled and optimized through the sliding rate, the tooth thickness and the backlash are distributed by balancing the fatigue strength of the paired gear, and the macroscopic geometric parameter optimization design of the gear 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 invention belongs to the technical field of structural strength design, and particularly relates to an airtight cabin angle section external load determination method and device.The method comprises the steps that S1, the length L1, the elasticity modulus E1 and the sectional inertia moment I1 of a cross beam connected with an angle section horizontal plate are determined, and the cross beam bears evenly-distributed aerodynamic loads q; s2, the length L2, the elastic modulus E2 and the section inertia moment I2 of the angle section vertical plate from the end, connected with the longitudinal beam, of the angle section vertical plate to the root section are determined; and S3, solving the external load borne by the angle section. The calculation time is shortened, the calculation is simple, and the scheme design efficiency of the structure is improved.

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 invention belongs to the technical field of structural strength design, and particularly relates to a grid structure shear modulus determination method and device.The method comprises the steps that S1, the long edge diagonal line size 2a, the short edge diagonal line size 2b and the beam frame width h of a grid unit are determined, the grid unit is the minimum repetitive unit forming the grid structure, and the grid unit is the minimum repetitive unit forming the grid structure; the grating unit is a rhombic beam frame, and the grating structure is a part of a full-aircraft structure; s2, the elastic modulus E of the material of the grid structure is obtained; s3, determining the shear modulus G12 of the grid structure according to the following formula: G12 = Ehab / L3; wherein L is the side length of each grating unit. According to the method, the calculation time is shortened, and the full-aircraft structure scheme iteration and parameter optimization efficiency is improved.

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 rib through hole optimization design method, and belongs to the field of airplane rib strength design. According to the rib through hole optimization design method, finite element software is utilized to simulate rib load, structural internal force is extracted, optimal geometric parameters of rib through holes are determined by referring to a mature engineering algorithm and wing surface design requirements through a parameterization means on the basis of meeting strength and rigidity from the aspect of process manufacturing, and the rib through hole with low manufacturing cost and high design efficiency is designed. And the light-weight structure product is simple in process molding. According to the method, on the premise that process manufacturing factors are considered in the design of the rib through hole structure, rapid iterative calculation is carried out, a lightweight configuration is obtained, and the overall safety, economy and reliability of the structure are guaranteed, the use performance potential of materials is fully excavated, the design period is shortened, and the cost is saved.

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 present application discloses a method for establishing a standard for civil aviation engine casting materials and verifying airworthiness, including the following steps: S1, establishing a standard for casting materials: establishing a first draft of the standard for casting materials, and completing the revision of the first draft of the standard for casting materials by obtaining the relationship between the structure, defects and mechanical properties of castings through casting simulation production and small-batch production of castings; S2, obtaining a model diagram for the mechanical properties of castings: inputting the chemical composition, process parameters and other components of the castings into the optimized casting simulation production software based on the relationship to obtain a model diagram for the mechanical properties of castings; S3, evaluating the simulated production of castings: comparing the mechanical properties model diagram of castings with the force diagram of castings, and improving the process or replacing the materials if the strength design requirements cannot be met; otherwise, conducting the first batch and batch production trials, verifying the locations with weak mechanical properties and high stress, and passing the material standard identification. The present application ensures that castings meet actual requirements and provides support for the airworthiness verification of civil aviation engine casting materials.

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.

The present invention discloses a traction beam cover plate structure that adapts to two track gauges. The traction beam cover plate is a folded and pressed symmetrical span structure, including a traction beam main plate located in the middle of the longitudinal direction and traction beam wing plates integrated on both sides of the traction beam main plate; the two wing plate surfaces of the main plate gradually widen and transitionally connect with the wing plates of equal width, the thickness of the main plate is greater than the thickness of the wing plate, and the thickness of the main plate on both wings gradually thins to both sides, and transitions to the same thickness as the wing plates; the middle part of the main plate is hollowed out to reduce the dead weight; side bearing assembly holes are arranged on the main plate and the wing plates, which are respectively used for narrow track or standard track change structures. The traction beam cover plate of the present invention follows the equal strength design, adopts a span structure, is hollowed out in the middle, and gradually widens in width to ensure the bearing strength; the thickness of the main plate is greater than the thickness of the wing plate, and the thickness of the main plate gradually changes, and transitions to the same thickness as the wing plate to reduce the dead weight; side bearing assembly holes are arranged on the main plate and the wing plates, which meet the needs of narrow track and standard track at the same time, and are convenient for track change assembly.

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.