CN-122021180-A - Method for simulating fracture performance of composite high-performance steel

CN122021180ACN 122021180 ACN122021180 ACN 122021180ACN-122021180-A

Abstract

The invention discloses a method for simulating fracture performance of composite high-performance steel, and relates to the technical field of numerical analysis of composite high-performance steel. The method comprises the steps of respectively obtaining stress-strain curves of standard tensile tests of single metal of a composite layer and a base layer, calibrating the fracture parameters of the single metal by carrying out tensile fracture prediction on the single metal, obtaining the shear performance and the adhesive performance indexes of a composite interface of the composite high-performance steel, adopting 'Cohesive contact' based on a cohesive force model to simulate the interface behavior, coupling tangential shear and normal adhesive action, and reproducing the whole process from interface damage to failure. And writing VUSDFLD a user subroutine by combining with an MMC breaking rule, integrating an MMC model with linear damage accumulation and softening rules into a layered model, and realizing the simulation of the breaking performance of the composite high-performance steel. The invention realizes the accurate simulation of the composite interface performance of the composite high-performance steel, and respectively considers the single-layer metal performance to predict the fracture of the composite high-performance steel.

Inventors

YANG YI
GAO FEI
GUO SHENG
CHEN JUNBO
Wang Zongdie

Assignees

华中科技大学

Dates

Publication Date: 20260512
Application Date: 20260317

Claims (6)

1. A method for simulating fracture performance of composite high-performance steel is characterized by comprising the following steps: respectively obtaining standard tensile stress strain curves of base layer single metal and multi-layer single metal which form the composite high-performance steel, respectively carrying out tensile fracture prediction analysis on the base layer single metal and the multi-layer single metal, and respectively comparing the base layer single metal and the multi-layer single metal with the standard tensile stress strain curves to obtain fracture parameters of the base layer single metal and the multi-layer single metal; establishing a layered model comprising a base layer and a multi-layer in finite element software according to the material property data of the composite high-performance steel, wherein the composite interface performance of the layered model is simulated by a Cohesive contact simulation method, and parameters required by the Cohesive contact simulation method are parameters required by defining Cohesive contact by analyzing the composite interface performance; Based on the fracture parameters of the basic unit simple substance metal and the multi-layer simple substance metal, MMC fracture models are respectively integrated in the layered models and are used for simulating the fracture performance of the composite high-performance steel.
2. The method for simulating the fracture performance of the composite high-performance steel product according to claim 1, wherein the obtaining of the fracture parameters of the basic-layer single metal and the multi-layer single metal comprises the following steps: Standard tensile tests are carried out on the basic unit metal and the multi-layer unit metal of the composite high-performance steel, so that standard tensile stress strain curves of the basic unit metal and the multi-layer unit metal of the composite high-performance steel are respectively obtained; After the basic-layer single-substance metal and the multi-layer single-substance metal exceed the limit tensile stress, verifying the stress-strain behavior after necking by adopting a finite element simulation method, defining the real stress-strain relationship after necking by adopting a weighted average method, and finishing material mechanics model definition data in a finite element model; Respectively carrying out tensile fracture prediction on the base layer single metal and the multi-layer single metal based on a material mechanical model in the finite element model, and comparing the tensile fracture prediction with the standard tensile stress strain curve to obtain fracture parameters of the base layer single metal and the multi-layer single metal; the true stress-strain relationship after necking is defined by a weighted average method, and functions for determining the true plastic stress exceeding the necking point and the true plastic strain are expressed as follows: wherein σ t is the true plastic stress beyond the necking point; The strain is true plastic strain, sigma n,t is true plastic stress corresponding to necking, epsilon n,t is true plastic strain corresponding to necking, W is a weighting factor, and calibration can be carried out through simulation.
3. The method for simulating fracture properties of a composite high-performance steel product according to claim 1, wherein the composite interface properties are analyzed based on composite interface shear properties and adhesion performance indexes of the composite high-performance steel product.
4. The method for simulating fracture properties of a composite high-performance steel product according to claim 1, wherein the Cohesive contact simulation method specifically comprises: the interface used for simulating the composite high-performance steel material evolves from the whole process of damage-debonding in the loading process; When the composite high-performance steel interface has potential crack or layering damage risk, the composite high-performance steel interface damage process with limited strength and limited fracture energy can be reflected.
5. The method for simulating the fracture performance of the composite high-performance steel material according to claim 1, wherein the MMC fracture model is used for calibrating relevant parameters of a single-layer metal MMC fracture model through fracture simulation prediction; The fracture model formula is expressed as: ; Wherein, the Is equivalent plastic strain when metal fails, A, n is model material parameter, the material parameters in equivalent stress-equivalent strain strengthening curve can be obtained by standard tensile test result, c 1 、c 2 is internal friction angle and maximum shear stress of material, eta and eta respectively Stress triaxial and regularized rad parameters respectively; 、、、 is a parameter describing the plastic relationship of metallic materials.
6. The method for simulating fracture properties of a composite high-performance steel product according to claim 1, wherein the MMC fracture model comprises a linear damage accumulation rule and a post-start softening rule.

Description

Method for simulating fracture performance of composite high-performance steel Technical Field The application relates to the technical field of numerical analysis of composite high-performance steel, in particular to a method for simulating fracture performance of composite high-performance steel. Background The composite high-performance steel is a multi-layer metal material formed by compounding two or more than two steel materials through rolling and other processes, and has obvious potential in the aspects of strength, toughness, weather resistance and the like because the composite high-performance steel can integrate the performance advantages of the steel of each component, and has become a novel material with great development prospect in the field of steel structure construction. Compared with common single homogeneous steel, the material has an inherent physical interface-composite interface in structure, and the mechanical properties (such as yield strength, elongation and the like) of each layer of steel are generally different. Therefore, the macroscopic mechanical behavior and the fracture performance of the composite interface are not only dependent on the properties of the component materials, but also are closely influenced by key characteristics such as the combination property of the composite interface, the composite ratio (namely the ratio of the thickness of the composite layer to the total thickness), and the like. The interface performance is directly related to the transmission efficiency and the cooperative working capacity of stress between layers under the action of load, and after materials with different elongations are compounded, stress and strain redistribution can be caused by uncoordinated deformation in the stress process, so that the fracture mode and the bearing capacity of the structure are finally affected. The method can accurately simulate the mechanical characteristics of the composite interface and the influence of the mechanical characteristics on the final breaking behavior of the material, and is an important basis for carrying out accurate finite element analysis and evaluating the structural safety and reliability of the composite high-performance steel member. However, the research on the material at present is insufficient, and further engineering application and popularization are restricted. In the aspect of interface performance research, the existing work is mainly focused on measuring the interface strength and toughness under a specific process by physical test means such as push-out tests, shearing tests and the like, and the tests can provide valuable data, but have high cost and long period, and the results are obviously influenced by specific samples and process parameters and lack of universal applicability. In the field of numerical simulation of interface performance research, a unified, efficient and accurate composite interface mechanical model and an implementation method thereof in a general finite element platform are not formed, so that the bonding, sliding and even delamination behaviors of an interface are difficult to reasonably characterize in component hierarchy analysis. In the aspect of fracture performance research, the bottleneck is more prominent at present, and the current fracture performance research is mainly focused on observing fracture morphology through a macroscopic test or analyzing fracture characteristics by means of a microscopic scanning electron microscope and the like, so that the method is helpful for understanding the fracture mechanism, but belongs to post analysis and cannot be used for prediction. In the prediction model of fracture performance, the existing ductile fracture criteria (such as a GTN model, a Johnson-Cook fracture criterion and the like) are established for a single homogeneous metal material, and the parameter calibration and the damage evolution mechanism cannot be directly applied to composite high-performance steel which is laminated by heterogeneous materials and has interface influence. In summary, due to the lack of a fracture model capable of simultaneously considering material heterogeneity, composite interface effect and composite ratio effect, it is difficult to accurately predict the whole process from the initiation and evolution of damage to the final fracture of composite high-performance steel and components thereof in simulation at present. Disclosure of Invention In view of the above, it is necessary to provide a method for simulating fracture properties of a composite high-performance steel. The technical scheme adopted in the specification is as follows: The specification provides a method for simulating fracture performance of composite high-performance steel, which comprises the following steps: respectively obtaining standard tensile stress strain curves of base layer single metal and multi-layer single metal which form the composite high-performance steel, respectively