7 results about "Static strength" patented technology

The invention belongs to the field of structural engineering, and particularly relates to a concrete compressive strength calculation method considering a strain rate effect and a size effect. The concrete compressive strength formula considering the size effect and the strain rate effect at the same time is deduced from the size effect formula and the strain rate effect formula of the concrete compressive strength. The formula comprises a constant term, a strain rate effect term, a size effect term and an interaction term. The constant item reflects the static strength of the concrete cubic test piece, the strain rate effect item reflects the strength improvement caused by strain rate increase, the size effect item reflects the strength reduction effect caused by test piece size increase, and the interaction item reflects the strain rate effect increase caused by the size increase and the size effect reduction caused by the strain rate increase. And finally, fitting all test data by adopting a multiple regression method to obtain various parameters of the concrete compressive strength. The formula fitting effect is good, the regression residual error is small, and the adaptability of the calculation method is verified.

The invention relates to the technical field of mechanical part design, and discloses a flange bolt connection layout optimization design method and related equipment.The method comprises the steps that flange basic parameters are obtained, and a rigidity calculation model is constructed based on the flange basic parameters; bolt margin parameters are determined through sealing surface pressure distribution based on a rigidity calculation model; bolt spacing parameters are determined through pressure distribution changes based on a rigidity calculation model; and performing parametric modeling and simulation checking on the determined bolt edge distance parameters and bolt spacing parameters by taking the pressure distribution change rate as a checking parameter to obtain a design result, and completing flange bolt connection layout optimization design through the design result. According to the method, discrete experience is upgraded into a continuous scientific model, the design reliability is remarkably improved, static strength design of a traditional empirical formula is replaced, and therefore the sealing reliability is remarkably improved, the method adapts to complex working conditions, and the design period is greatly shortened.

The invention provides a strength and fatigue analysis method and equipment for a welded integrated planet carrier, belongs to the technical field of welding processes and weld strength and fatigue evaluation, and establishes a temperature / phase dependent material performance parameter library, and adopts Johnson-Mehl-Avrami and Koidinen-Marburst formulas to process phase change kinetics. And a welding process simulation system is constructed through single-claw model simplification, grid gradient control and a 3D Gaussian heat source model. Data transmission and rebalance verification are achieved, and it is ensured that the displacement error is smaller than or equal to 0.85%. And supplementing a complete model and setting boundary conditions, introducing 50% residual stress relaxation correction, dividing the welding seam / heat influence area into 10 groups according to the yield strength difference, and calculating the fatigue life by adopting a Basquin formula. According to the method, through multi-physics field coupling and sub-model subdivision, accurate evaluation of the static strength and the fatigue life of the welding structure is achieved, and the application reliability is improved.

The invention relates to a high-ice-grade controllable-pitch propeller hub assembly test model design method, which comprises the steps of S1, designing a scaling test model structure based on structural characteristics of a high-ice-grade controllable-pitch propeller hub assembly prototype; s2, determining a similarity criterion of the prototype machine and the test model, and calculating a similarity coefficient on the basis of geometric dimensions, material performance and load parameters of the prototype machine and the test model; s3, scaling the structural size of the prototype machine according to the similarity coefficient, and determining geometric parameters of each part of the test model; s4, selecting a test model material meeting similar criteria with the prototype material performance, and ensuring that the stress-strain characteristics of the test model are consistent with those of the prototype; s5, reproducing an anti-loose structure of the prototype machine in the test model, wherein the anti-loose structure comprises an arrangement mode of anti-loose stainless steel wires and anti-loose strips; and S6, based on the zoomed structure and the selected material, assembling a test model, carrying out a static strength and fatigue life reliability test, and verifying the mechanical similarity between the test model and a prototype.

The invention belongs to the technical field of additive manufacturing, and discloses a static strength test device and an airworthiness conformity evaluation method.The device is used for measuring the static strength of a gooseneck joint and comprises a fixed base and a movable base. One end of the gooseneck connector is detachably connected to the fixed base, the other end of the gooseneck connector is detachably connected to the movable base, the movable base can move in the first horizontal direction relative to the fixed base, and the first horizontal direction is parallel to the extending direction of the gooseneck connector. Through the arrangement, the static strength test device can efficiently and accurately realize the static strength test of the gooseneck joint. According to the airworthiness conformity evaluation method, the static strength experimental device is used, and the airworthiness conformity of the gooseneck joint can be well verified and evaluated.

This invention belongs to the field of flexible body aircraft technology, specifically disclosing a method for measuring the stiffness of a flexible wing. This method is based on a static strength and stiffness measurement platform for flexible wings, which includes a test bench support frame, a specimen fixing platform, support rods, tension ropes, a rangefinder, and a counterweight loading component. The stiffness measurement method includes: calculating the test load; installing the flexible wing test specimen; marking the flexible wing test specimen; designing and preparing the counterweight loading component; applying equivalent loading under the test condition; measuring the bending and torsional stiffness boundaries; and post-processing the measurement results. This measurement method significantly improves loading accuracy and can simulate loads under bending, torsion, or combined bending and torsion conditions of flexible wings to obtain stiffness and instability boundaries. It overcomes the shortcomings of traditional flexible wing structural stiffness measurement methods, which can only perform rough loading and cannot handle heavy loads, and can measure the load-bearing capacity and stiffness of high aspect ratio, high load-bearing special-purpose flexible wings.

This invention discloses a method for evaluating the static strength of welded structures, comprising: establishing a finite element model of the welded structure and performing finite element static strength calculations using a coarse mesh to locate weld hotspots; refining the mesh at the weld hotspot locations and calculating the total weld stress through internal stress linearization; determining material parameters, including yield strength, tensile strength, elongation at break, Young's modulus, tangent modulus, and total critical strain; determining the section modulus based on the material parameters; determining the welding coefficient based on weld type, weld quality, and stress type; calculating the weld strength based on the section modulus, welding coefficient, and material parameters; determining a safety factor based on the material parameters and an assessment of the consequences of weld failure; and obtaining the evaluation result by comparing the ratio of the weld strength to the safety factor with the total weld stress. This invention can more realistically reflect the stress state at the weld location and improve the accuracy of the evaluation by refining the design parameters.