8 results about "Damage tolerance" patented technology

The application discloses a kind of laminated composite intercalation repair methods, belong to laminated composite maintenance technical field.The application uses the way of multilayer intercalation reinforcement patch, significantly increase the bonding area of patch and original laminated laminated composite material, can effectively improve the bonding strength of repair area, so that repair area will not become laminated laminated composite material / member dangerous area;The bonding surface is composed of multiple planes, and adjacent bonding surfaces bear tensile or shear load respectively, and after debonding or damage of a certain bonding surface, the crack will not spread to other bonding surfaces, significantly enhance the damage tolerance of repair bonding area, and further improve the mechanical properties of repair material / member.

The application belongs to the technical field of aero-engine composite material fan blade damage tolerance performance evaluation, and specifically discloses a composite material high-speed soft body impact damage pre-preparation test device and a test method, which comprises an air compressor, an air chamber, an air gun support table, a composite material high-speed soft body impact damage pre-preparation test table, a soft bullet launching system and a multi-view camera monitoring system; the air chamber is connected with the air compressor and the soft bullet launching system at two ends respectively, the soft bullet launching system is located on the air gun support table, the air gun support table is connected with the composite material high-speed soft body impact damage pre-preparation test table, and the multi-view camera monitoring system is arranged around the composite material high-speed soft body impact damage pre-preparation test table. The application solves the problems that the existing technology may cause damage in the clamping area, affect the reliability of the test result of the residual tensile bearing capacity after impact, and lack the controllable problem of the high-speed soft body impact damage area.

The application provides a roller straightening process for improving shape, position and size of 7150 aluminum alloy profile for aviation, which adopts a straightening device for treatment; the straightening device comprises at least one lower roller piece and one upper roller piece, the lower roller piece is located below the profile, the upper roller piece is located above the profile and contacts the profile to generate a pressing amount; when the bending amount of the profile is 12-20mm in height at the head and tail, the pressing amount is 3-4mm when the hardness of the profile is 90-100HB; the pressing amount is 4-6mm when the hardness of the profile is 100-120HB; and the pressing amount is 6-8mm when the hardness of the profile is 120-140HB. According to the bending degree and hardness of the 7150 aluminum alloy profile, the pressing amount of the upper roller piece is determined in the roller straightening process, the profile is straightened under the premise of ensuring the damage tolerance of the 7150 aluminum alloy profile, so that the material can be applied in the aviation profile; and the process has the advantages of reasonable process design and easy implementation.

The application discloses a crack tip cracking prediction method and system for ductile metal materials, which can accurately characterize the strain energy density distribution of the crack tip of a ductile metal structure, and accurately and quantitatively characterize the crack initiation criterion verification and damage tolerance fatigue life prediction of the crack tip. The method comprises the following steps: obtaining the strain field of the crack tip of the ductile metal material to be measured based on DIC technology; constructing a constitutive model of the ductile metal material to be measured based on a uniaxial tensile test; calculating and obtaining the stress field of the crack tip of the ductile metal material to be measured according to the strain field and the constitutive model based on plastic deformation theory and Newton-Raphson iteration algorithm; calculating the elastic strain energy density field and the plastic strain energy density field of the crack tip of the ductile metal material to be measured according to the obtained stress field and strain field, and obtaining the critical plastic strain energy; and predicting the cracking of the crack tip of the ductile metal material to be measured according to the critical plastic strain energy.

This invention discloses a biomimetic dual-scale lattice metamaterial with high damage tolerance and electromagnetic absorption performance, and its design method. It belongs to the field of integrated design technology of damage tolerance design and electromagnetic function. This invention uses finite element simulation software, based on a first-order unit lattice, and adopts a recursive modeling method to design a second-order dual-scale lattice structure. By rationally designing the topology and size parameters of the dual-scale lattice, the structure maintains a high electromagnetic absorption rate over a wide frequency range, improves the damage tolerance of the structure, and, while maintaining a low relative density, makes it have high specific stiffness and specific strength, thus achieving mechanical-electromagnetic integrated optimization.

The application discloses a thermal-mechanical fatigue crack propagation rate testing method based on rigidity and crack tip strain field, comprising the following steps: firstly, a relationship function between normalized crack length and normalized rigidity is established through finite element calculation; secondly, DIC speckle preparation is carried out for observing crack propagation and strain field analysis; then, a thermal-mechanical fatigue test is carried out, crack length is calculated based on rigidity change results of the test, an a-N relationship curve is drawn combined with DIC synchronous observation results, and comparative analysis is carried out; finally, crack propagation rate is calculated through a three-point moving average secant method, and the size of a plastic zone at a crack tip is determined according to DIC strain field analysis, so that the accurate test of the crack propagation rate is realized. The application can effectively test the fatigue crack propagation behavior under the thermal-mechanical coupling effect, and accurately obtain the thermal-mechanical fatigue crack propagation rate combined with the crack tip strain field measurement method, so as to provide test data support for damage tolerance design and structure integrity evaluation of high-temperature pressure-bearing equipment.

This invention belongs to the field of life prediction technology, specifically relating to an online prediction method for the remaining life (RUL) of a chlorine-rich high-temperature environment coupled with stress in a system. The method includes the following steps: acquiring linear polarization data measured by electrochemical methods; calculating the corrosion current density using the linear polarization method and converting the instantaneous thickness loss rate and cumulative thickness loss according to Faraday's law; mapping the cumulative thickness loss to the evolution of the load-bearing section, thereby obtaining the stress evolving over time; determining the instantaneous creep strain rate; describing the damage evolution; determining the failure time based on the minimum safe thickness and / or damage threshold, and outputting the RUL and early warning; and introducing a risk index and dynamic threshold for post-prediction risk control. This invention enables the measurement of thermally stress-induced high-temperature ash corrosion through multi-source fusion and introduces a risk index and damage tolerance criteria to achieve early warning, significantly improving the accuracy and real-time performance of life assessment under complex operating conditions.

The present application relates to the technical field of aero-engine probability damage tolerance evaluation, and particularly relates to a triangular quadrilateral two-dimensional hybrid grid stress partitioning method for aero-engine wheel disc, comprising the following steps: obtaining finite element stress analysis result data of the wheel disc component, preprocessing, and obtaining preprocessed input data; obtaining a convex hull boundary formed by all nodes by using the Graham method, and obtaining a graph boundary based on the convex hull boundary; obtaining stress pre-grouping and element type pre-grouping of each grid element; establishing an element adjacency graph based on the adjacent relationship of each grid element; searching the element adjacency graph by using a breadth-first search algorithm, and dividing grid elements with the same stress pre-grouping and the same element type pre-grouping into the same partition; and finally obtaining partition numbers of each grid element as the wheel disc stress partitioning result; the present application can improve the calculation accuracy and efficiency of the wheel disc stress partitioning.