78 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 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 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 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 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 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 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.

The invention provides a composite material stringer end compression strength checking method which comprises the following steps: carrying out a compression strength test on a broken composite material U-shaped stringer end at a rib station to obtain test data required by the stringer end compression strength checking method; a damage influence factor and an environment influence factor are obtained from the test data, and a strength design value of the test configuration considering damage and environment influence is obtained; establishing a fine finite element model of the stringer end part test piece, and verifying the modeling method by adopting test data at lossless room temperature; evaluating the influence of different configuration factors on the compression performance of the stringer end part by adopting a verified stringer end part fine finite element model modeling method, and judging the configuration factors influencing the strength; and fitting to obtain a stringer end part strength check design value formula, and determining a strength check method. According to the method for checking the compression strength of the end part of the stringer, the safety and the accuracy of strength checking are ensured, and the efficiency of strength checking is greatly improved.

The invention discloses a bridge component design method and system based on a degradation model and a storage medium, and the method comprises the steps: determining a bridge structure importance coefficient and a load effect combination value according to the design specifications of highway bridges and culverts; according to the bearing capacity function of the whole life cycle of the component, the bearing capacity design value of the component is calculated, and the bearing capacity function of the whole life cycle of the component is constructed by combining the bridge component degradation model and the bearing capacity function of the component; according to the fact that the product of the bridge structure importance coefficient and the load effect combination value is smaller than or equal to the component bearing capacity design value, the material strength design value and the geometric parameter design value of the component are determined; according to the method, the static reliability theory is expanded into a time-varying reliability design framework, so that the material strength design value and the geometric parameter design value of the component designed according to the bearing capacity function of the whole life cycle of the component are kept in a good performance state in each period in the operation cycle.

A golf ball composition is disclosed herein that includes at least one layer formed from metal foam. The metal foam can provide lightweight, durable, and high strength design parameters for golf ball constructions in order to provide greater adaptability and customizability, among other advantages.

The application provides a D-shaped beam composite material blade root section fatigue test method and system, and belongs to the technical field of helicopter structure strength design. The method comprises the following steps: patching and calibrating a D-shaped beam blade root section test piece; determining a fatigue test static load and a dynamic load; and then implementing a D-shaped beam blade root section fatigue test. The application proposes a method for applying a static load of a waving bending moment and a wobbling bending moment in a D-shaped beam blade fatigue test. The test static load covers the theoretical static load, solves the problem caused by the static load correction, and can effectively evaluate the fatigue performance of the D-shaped beam blade root section.

The application discloses a load prediction-based cargo box bottom plate structure strength design optimization method and system, belongs to the technical field of freight vehicle structure design, and through construction of a load prediction model of dynamic distribution states of goods in a cargo box, calculation of maximum equivalent stresses of each node in a bottom plate grid area and normalization processing, a stress intensity coefficient matrix is formed; a high-risk area is identified and a reinforcement target area set is constructed; initial parameters of a bottom plate structure are acquired, a finite element model is established, and adjustable structure parameters are set in the target area; a candidate structure design scheme set is generated, simulation calculation is executed, structure total mass, maximum stress value and first-order natural frequency of each scheme are extracted, and a performance evaluation vector is formed; an optimal design scheme is selected through a multi-objective optimization algorithm, and structure parameters thereof are output as a final design result; the application realizes structure optimization design of the cargo box bottom plate under complex load working conditions, and has high engineering adaptability and practical value.

The invention provides a strength design method for a deep-sea light ring rib cylindrical shell. The strength design method specifically comprises the following steps: (1) establishing a geometric model of the ring rib cylindrical shell when the ring rib cylindrical shell externally bears hydrostatic pressure; (2) carrying out stress analysis on the geometric model to obtain a cylindrical shell deflection curve expression containing unknown parameters; and (3) confirming boundary conditions of the geometric model, solving unknown parameters in the cylindrical shell deflection curve expression according to the boundary conditions, substituting the unknown parameters into the cylindrical shell deflection curve expression so as to obtain a complete deflection curve analytical expression, calculating stress values of different positions of the shell based on the deflection curve analytical expression, and calculating the stress values of different positions of the shell. And structural strength design is carried out according to geometric parameters of the ring rib cylindrical shell structure. The method is reasonable in conception, elastic boundary conditions are used at the ribs, the new boundary conditions can better describe the constraint condition of the reinforced cylindrical shell at the joint of the ribs and the shell according to material characteristics, and the method can be used for annular rib cylindrical shell structures of different materials and is more universal and accurate.

This invention provides a method for measuring and evaluating stress concentration in a cage-type elastic support, belonging to the field of measurement and testing technology. The method includes the following steps: First, determining the stiffness of the elastic support through calibration tests; second, calculating the stress distribution formula of the cage bars based on their structural dimensions; third, obtaining the analytical solution for stress concentration using the multivariate function extremum method; fourth, obtaining the theoretical solution for the strain gauge measurement range using the area integral method; and fifth, measuring, evaluating, and correcting the stress concentration to obtain the measured value of the stress concentration in the cage bars. This invention solves the problem of inaccurate measurement location and data in existing technologies when measuring stress concentration at the root of the cage bars, providing accurate data support for the structural strength design and fatigue life estimation of elastic supports.

The invention relates to the technical field of structural engineering, in particular to a reinforced concrete beam flexural capacity degradation prediction and optimization method and system. Comprising the following steps: S1, constructing a flexural capacity time-varying model; s2, calculating the area of a bending moment bearing steel bar and the tensile strength design value of the bending moment bearing steel bar, considering the time-varying effective height after corrosion and bonding degradation of the steel bar and the concrete strength design value, and substituting into the bending bearing capacity time-varying model to obtain the bending bearing capacity of the reinforced concrete beam; s3, setting a plurality of optimization schemes according to the flexural capacity; s4, performing Monte Carlo simulation loop on each optimization scheme, iterating to perform the steps S2 to S3, and stopping iteration when all optimization schemes are iterated once; according to the method, the flexural capacity degradation prediction precision is improved.

The invention provides an aero-engine structural strength design method in combination with a life demand. The method comprises the following steps: acquiring an aerodynamic performance calculation result and a secondary flow calculation result; performing overall structure proofing design according to the aerodynamic performance calculation result and the secondary flow calculation result; carrying out modeling design on the overall structure to obtain a structure model; performing strength design based on the structure model to obtain a strength model; structural integrity design is conducted on the strength model, and structural strength and service life review design is conducted on the basis of structural integrity; and the design is completed under the condition that the strength and service life requirements are met. According to the method, under the condition that the service life requirement of the engine is met, strength design is carried out on the engine structure according to the service life requirement, meanwhile, integrity design of the engine structure is carried out, lean design is achieved, the service life requirement and the strength requirement are met in the design process, and large redundancy strength cannot be caused; the integrated design of strength and structure is realized, and the airworthiness safety of engine operation is ensured.

The invention belongs to the technical field of geotechnical engineering, and discloses a rib material pull-down testing device and method for a reinforced earth retaining wall, rolling friction force between rollers and a longitudinal beam at the rear end of a model box is used for replacing sliding friction force generated when a retaining wall module is in direct contact with the longitudinal beam at the rear end of the model box, and an existing retaining wall is not in contact with the side wall of the model box; and when the pull-down force of the rib material is monitored, the loss caused by the friction force is effectively reduced. The pull-down force obtained through testing can provide a clear evidence for the strain concentration phenomenon at the joint of the rib material and the existing retaining wall, and innovation of a rib material strength design method is promoted; and the total pull-down force obtained by testing can be used as an exact and extra load to be input into the foundation stability calculation of the existing retaining wall, and is used for evaluating the bearing capacity stability and deformation of the foundation below the existing retaining wall.

The application provides a turbine blade design method with reverse rotation function, which fully considers the structural characteristics of the turbine blade with reverse rotation function, namely, after the reverse blade is added, the blade mass and centrifugal force are increased, the difficulty of the turbine structure strength design is increased, the structure characteristics of the approximately symmetrical arrangement of the forward / reverse blade make the structure design of the transition section more complex, in addition, the vibration problem of the turbine blade with reverse rotation function is relatively prominent. The design method provided by the application takes the turbine blade with high reliability, long service life and low stress as the target, and innovatively provides the transition section with pre-twist function, the design method with the shaped reinforcing rib and the like in the design method. The turbine blade with high reliability and long service life can be obtained through the design method provided by the application. The application has the characteristics of simple operation and comprehensive consideration.