10 results about "Yield limit" patented technology

The invention provides a macroscopic finite element simulation analysis method and device for a sealing element considering plastic deformation, and belongs to the field of sealing element design. The method comprises the following steps: acquiring an engineering stress-strain curve of a plastic material in a compression state; converting the engineering stress-strain curve into a real stress-strain curve; determining a yield limit, and taking a strain point corresponding to the yield limit as a demarcation point of elasticity and plastic deformation; an elastic section of a real stress-strain curve is extracted, the elastic modulus is calculated, and the Poisson's ratio is obtained through axial and transverse strain measurement in a uniaxial compression test; a true stress-strain curve plastic section is extracted, and a multi-linear isotropic hardening model is established; constructing a complete elastic-plastic constitutive model covering the elastic deformation area and the plastic deformation area; the stress distribution, the strain response and the contact performance of the plastic sealing element in a compression deformation state are simulated. According to the method and the device provided by the invention, the problem that the result does not conform to the reality due to the fact that only elastic modulus and Poisson's ratio are used in existing sealing element simulation can be solved.

The application discloses a GIS busbar state control method, and relates to the technical field of GIS busbars, and comprises the following steps: arranging a GIS busbar in a GIS busbar state control device; determining axial stress of the GIS busbar in a temperature difference change state respectively; determining a deformation degree of the GIS busbar according to the axial stress and a material yield limit of the GIS busbar; and protecting the GIS busbar by the control device. According to the actual situation of a GIS busbar operation environment, axial stress of the GIS busbar in a temperature difference change state is tracked, so that potential temperature change defects of the busbar are determined, and the state of the GIS busbar is controlled by using the GIS busbar state control device, thereby reducing the risk that components are damaged due to deformation of the GIS busbar.

This invention provides a method and apparatus for detecting the reuse of centrifuge tubes in ultra-high-speed centrifuges, comprising the following steps: S1, pressurizing and filling a medium into a new centrifuge tube, and detecting the diameter deformation of the centrifuge tube online; S2, using the maximum pressure that the centrifuge tube can withstand to return to its initial diameter as the yield limit pressure value; S3, replacing the centrifuge tube to be reused, pressurizing and filling the centrifuge tube to be reused with a medium, controlling the reuse pressure value at 75%~95% of the yield limit pressure value; S4, detecting the diameter deformation of the centrifuge tube to be reused online; S5, selecting the centrifuge tube that can return to its initial diameter as the reuse centrifuge tube. This invention can detect centrifuge tubes and determine whether they can be safely reused, significantly reducing experimental costs. It can be used to detect whether replacement centrifuge tubes meet the application requirements of ultra-high-speed centrifuges. It prevents substandard centrifuge tubes from entering the ultra-high-speed centrifuge, causing equipment damage or even sample leakage.

This invention discloses a variable contact rolling-sliding composite bearing and its design method, relating to the field of bearing technology. The bearing includes an outer ring, an inner ring, bearing rollers, and a cage. The diameter of the bearing rollers is larger than the axial height of the cage to form an initial clearance. When the external load is small, the bearing rollers bear the load alone, and the bearing is in a pure rolling contact state. When the external load increases to the point that the bearing rollers undergo elastic deformation and the initial clearance closes, the end face of the cage contacts the raceway surface of the outer ring, sharing the load with the bearing rollers, and the bearing switches to a rolling-sliding composite contact state. The design method involves: calculating the roller deformation to determine the critical load; establishing a spring stiffness model for the rollers and cage to solve for the load distribution; checking whether the cage contact stress is lower than the yield limit; if it exceeds the limit, increasing the initial clearance and iteratively optimizing. This invention achieves adaptive switching of the bearing's operating mode, enabling low friction under light loads and high load capacity under heavy loads, and the design method is universal and reliable.

The present application provides a macroscopic finite element simulation analysis method and device for seals considering plastic deformation, which belongs to the field of seal design. The method includes: obtaining the engineering stress-strain curve of the plastic material under compression; converting the engineering stress-strain curve into a true stress-strain curve; determining the yield limit, and using the strain point corresponding to the yield limit as the dividing point between elastic and plastic deformation; extracting the elastic section of the true stress-strain curve, calculating the elastic modulus, and obtaining the Poisson's ratio by measuring the axial and lateral strains in the uniaxial compression test; extracting the plastic section of the true stress-strain curve, and establishing a multilinear isotropic hardening model; constructing a complete elastic-plastic constitutive model covering the elastic deformation zone and the plastic deformation zone; simulating the stress distribution, strain response and contact performance of plastic seals under compression deformation. The method and device provided in the present application can solve the problem that the existing seal simulation only uses the elastic modulus and Poisson's ratio, resulting in results that are inconsistent with reality.

The present invention belongs to the field of aero-engines and relates to the design technology of the thickness of elastic ring segments. A method and a system for designing the thickness of elastic ring segments of an aero-engine are provided. The method includes: dividing the elastic ring into multiple segments, and obtaining the flexibility coefficient of the elastic ring segments according to the given initial value of the segment thickness and the elastic modulus; obtaining the initial value of the stiffness of the elastic ring based on the segment flexibility according to the flexibility coefficient of the elastic ring segments, the number of segments, and the included angle between adjacent inner and outer bosses; obtaining the maximum segment thickness of the elastic ring according to the maximum stiffness limit value of the elastic ring and the initial value of the stiffness of the elastic ring; obtaining the minimum segment thickness according to the maximum radial load of the elastic ring and the yield limit; through the finite element method, obtaining the final segment thickness from the interval formed by the minimum segment thickness and the maximum segment thickness according to the maximum stiffness limit value of the elastic ring. The elastic ring designed by the method of the present invention has good vibration reduction effect in the overall machine vibration, and the fatigue life meets the design requirements.

The application discloses a composite stress relieving device for aluminum plate in the field of plate flattening, which comprises a roller flattening machine and a stretching mechanism. The roller flattening machine is formed by the staggered arrangement of upper roller groups and lower roller groups into an S-shaped shaping channel for repeatedly bending the aluminum plate. The roller shafts rotate synchronously through a driving mechanism and convey the aluminum plate to advance. The stretching mechanism has clamping jaws and a hydraulic driving mechanism to exert an axial traction force on the aluminum plate. The traction linear velocity of the stretching mechanism is configured to be greater than the linear velocity of the roller shafts in the roller flattening machine, so as to form a stable speed difference between them to force the aluminum plate to plastically extend in the S-shaped shaping channel along the axial direction. Through the combined action of the two plastic deformations, the overall cross section of the aluminum plate is in a plastic stress state exceeding the yield limit, thereby realizing the synchronous and efficient elimination of the in-plane and thickness direction residual stress of the aluminum plate. The technical scheme effectively integrates the stress relieving process, and significantly improves the stress relieving efficiency.

The application provides a force-bearing casing support plate and mounting edge axial distance design method, and relates to the technical field of an aero-engine. The method comprises the following steps: S1, determining the maximum load of the force-bearing casing mounting edge according to a set engine design method; S2, equivalent the force and moment of the maximum load acting on the casing mounting edge to a maximum resultant force F 合 ; S3, taking the material yield limit as the maximum stress limit value of the force-bearing support plate root rounding position, calculating the minimum axial distance l min of the force-bearing casing support plate and the mounting edge according to the maximum resultant force F 合 of the force-bearing casing mounting edge; S4, taking the minimum rigidity of the casing mounting edge as the minimum rigidity of the casing mounting edge according to the maximum resultant force F 合 , calculating the maximum axial distance l max of the force-bearing casing support plate and the mounting edge according to the minimum rigidity. The application can guarantee that the maximum stress level and the minimum deformation of the casing meet the design requirements, and realize the optimal solution of the strength life and the rigidity.

The application provides a ship three-dimensional design method and system for finite element analysis, comprising the following steps: S1, obtaining a ship design specification, wherein the ship design specification comprises design information such as ship length, ship width, ship height, ship speed and ship structure requirements; S2, constructing an entity model in a three-dimensional design software according to the ship design specification; S3, obtaining structure information of a plate, a profile, a knee plate and a hole in the entity model, generating a facet structure according to the structure information in the entity model, and combining corresponding material properties such as material density, elastic modulus, Poisson's ratio and yield limit in a model base library to generate a facet model for finite element analysis; and S4, performing finite element analysis on the facet model, and adjusting the constructed entity model in the three-dimensional design software according to the finite element analysis result. The method reduces the operation of a designer, improves the model design efficiency and shortens the ship design cycle.

The present invention relates to a roll system of an integral beam plate leveling machine with different roll diameters, which includes an upper roll system and a lower roll system. The upper roll system includes upper working rolls and upper supporting rolls, and the lower roll system includes lower supporting rolls and lower working rolls. The axes of the upper working rolls are located in the same plane. The diameters of the first upper working roll to the fourth upper working roll from the inlet gradually increase, and the diameters of the fourth upper working roll to the last upper working roll at the outlet are equal. The diameters of the lower working rolls are the same and their axes are in the same plane. Each upper working roll is in tangential contact with two upper supporting rolls, and the diameters of the upper supporting rolls are equal. The axial heights of the first upper supporting roll at the inlet and the second upper supporting roll at the inlet are equal, and the axial heights of the first upper supporting roll at the end of the outlet and the second upper supporting roll at the end of the outlet are equal. The beneficial effects of the present invention are as follows: it can achieve the step-by-step biting of the plate, obtain a greater biting and feeding force, achieve a greater bending amount of the plate, and improve the feeding and leveling effect of plates with a high yield limit and a large original flatness deviation.