阅读说明：本技术 一种超高强度钢板u型件多道次渐进折弯成形的有限元模拟方法 (Finite element simulation method for multi-pass progressive bending forming of ultra-high strength steel plate U-shaped part ) 是由 董文超 陈世坤 陆善平 刘丽华 高燕 闫强军 于 2021-08-12 设计创作，主要内容包括：本发明公开了一种超高强度钢板U型件多道次渐进折弯成形的有限元模拟方法。属于有限元模拟领域；操作步骤：建立超高强度钢材料的本构模型；设计超高强度钢折弯道次和每道次初始折弯量；建立第一道次超高强度钢板U型件折弯成形有限元模型；采用动态显示算法模拟第一道次折弯成形过程；建立第一道次超高强度钢板U型件折弯成形后回弹有限元模型；采用静态隐式算法模拟第一道次折弯成形后的回弹过程；重复上述步骤,计算其他道次折弯成形、回弹后的应力、应变、力、变形量等；验证设计的折弯道次和每道次折弯量。本发明通过数值模拟,实现各道次折弯成形的折弯量和回弹量的预测,为制定超高强度钢板U型件多道次渐进折弯成形工艺提供依据。(The invention discloses a finite element simulation method for multi-pass progressive bending forming of an ultra-high strength steel plate U-shaped part. Belonging to the field of finite element simulation; the method comprises the following operation steps: establishing a constitutive model of the ultrahigh-strength steel material; designing the bending pass and the initial bending amount of each pass of the ultrahigh-strength steel; establishing a bending forming finite element model of a first-pass ultrahigh-strength steel plate U-shaped part; simulating a first bending forming process by adopting a dynamic display algorithm; establishing a springback finite element model after the first-pass ultrahigh-strength steel plate U-shaped part is bent and formed; simulating a springback process after the first bending forming by adopting a static implicit algorithm; repeating the steps, and calculating the stress, strain, force, deformation and the like after bending forming and springback of other passes; and verifying the designed bending pass and the bending amount of each pass. According to the invention, through numerical simulation, the bending amount and the springback amount of each pass of bending forming are predicted, and a basis is provided for formulating the multi-pass progressive bending forming process of the ultra-high strength steel plate U-shaped part.)

1. A finite element simulation method for multi-pass progressive bending forming of an ultra-high strength steel plate U-shaped part is characterized by comprising the following specific operation steps:

(1) establishing a constitutive model of the ultrahigh-strength steel material;

(2) designing the bending pass and the bending amount of each pass of the ultrahigh-strength steel according to the size of the U-shaped part;

(3) establishing a bending forming finite element model of the first-pass ultrahigh-strength steel plate U-shaped part;

(4) setting an analysis step according to the obtained constitutive model and the finite element model, simulating a first-pass bending forming process by adopting a dynamic display algorithm, and calculating stress, strain, force and deformation in the bending process;

(5) establishing a springback finite element model after bending and forming a first-time ultrahigh-strength steel plate U-shaped piece by adopting the restarting function of ABAQUS;

(6) simulating the springback process after the first bending forming by adopting a static implicit algorithm, and calculating stress, strain, force and deformation in the springback process;

(7) adopting the restarting function of ABAQUS, repeating the steps (3) to (6), and respectively calculating the stress, strain, force and deformation after bending forming and rebounding of other passes;

(8) and (3) comparing simulation results according to the size of the U-shaped part product, and verifying the bending pass designed in the step (2) and the bending amount of each pass.

2. A finite element simulation method for multi-pass progressive bending forming of ultra-high strength steel plate U-shaped members according to claim 1,

in the step (1), the specific operation steps of establishing the constitutive model of the ultrahigh-strength steel material are as follows:

(1.1) cutting and processing a tensile sample from the rolled-heat-treated ultrahigh-strength steel plate along a parallel rolling direction, a vertical rolling direction and a direction forming an angle of 45 degrees with the rolling direction respectively;

(1.2) carrying out unidirectional tensile test on tensile samples in different directions, recording deformation during tensile by adopting an extensometer, obtaining a force-deformation curve during tensile, and obtaining a tensile true stress-true strain curve of the tensile sample in each direction according to the curve, the sectional area of the sample and the gauge length of the extensometer;

(1.3) obtaining the plastic strain ratio of the material in each direction, the Hill48 anisotropic yield criterion parameters and the A-F nonlinear follow-up strengthening model parameters according to the tensile true stress-true strain curve of the tensile sample in each direction;

and (1.4) writing the obtained parameters into a program file based on ABAQUS software secondary development.

3. A finite element simulation method for multi-pass progressive bending forming of ultra-high strength steel plate U-shaped members according to claim 1,

in the step (3), the specific operation steps of establishing the bending forming finite element model of the first-pass ultrahigh-strength steel plate U-shaped part are as follows:

(3.1) establishing an ultrahigh-strength steel plate, a bending male die and a bending female die solid model by using ABAQUS software;

(3.2) carrying out meshing on the entity model, and assembling and positioning the ultrahigh-strength steel plate, the bending male die and the bending female die;

(3.3) respectively defining the contact conditions between the ultrahigh-strength steel plate and the bending male die and between the ultrahigh-strength steel plate and the bending female die, defining the condition of fixing the boundary of the female die, and defining the downward distance of the male die, namely the bending amount;

and (3.4) writing the secondarily developed program file completed in the step (1.4) into ABAQUS software.

4. A finite element simulation method for multi-pass progressive bending forming of ultra-high strength steel plate U-shaped members according to claim 1,

in the step (5), the specific operation steps of establishing the springback finite element model after the first-pass ultrahigh-strength steel plate U-shaped part is bent and formed are as follows:

(5.1) eliminating the definition of the contact conditions among the ultrahigh-strength steel plate, the bending male die and the bending female die in the step (3.3);

(5.2) defining displacement boundary conditions of the bent ultrahigh-strength steel plate;

and (5.3) taking the stress and the strain after the first bending as initial conditions for calculating the resilience.

Technical Field

The invention belongs to the field of finite element simulation, and relates to a finite element simulation method for multi-pass progressive bending forming of an ultra-high strength steel plate U-shaped part.

Background

In the prior art, energy conservation, emission reduction and safety are general trends of modern engineering machinery development, and the realization of light weight of the engineering machinery is an important way for energy conservation and emission reduction. In recent years, ultra-high strength steel plates with strength level of 960MPa or even higher are applied to engineering machinery, and the large deformation impact resistance and the durability strength of the engineering machinery can be improved while the weight is reduced. However, due to the high strength and large springback of the ultra-high strength steel, it is difficult to make a suitable bending process. Particularly, parts with complex shapes (such as U-shaped parts) are difficult to bend and form at one time, and a proper multi-pass progressive bending process needs to be established. The research on various factors of springback in the gradual forming process of the sheet metal is carried out by Pazerman and the like (Pazerman, Mojianhua, Korea flight, Gong climb and springback compensation of multi-pass gradual bending forming of the sheet metal, university of science and technology in Huazhong (Nature science edition) 2010,38(5): 105-. The patent (a plate multi-pass progressive bending forming device. national invention patent 2014) develops a special forming device aiming at the bending forming of straight pipe parts and inclined conical pipe parts. For the manufacturing field, what is more concerned is how to smoothly complete the multi-pass progressive bending forming of the ultrahigh-strength steel, i.e. to obtain a proper bending process (bending amount). At present, a bending process is mainly formulated by manufacturing enterprises through experiments and manual experiences, a great deal of time and energy are consumed, and the development cost of a new product is very high. With the rapid development of computer technology and finite element numerical simulation technology, the test and theoretical numerical simulation technology are combined, and powerful support is provided for the formulation of the bending process of the ultrahigh-strength steel plate. . Therefore, it is necessary to develop a finite element simulation method for multi-pass progressive bending forming of the ultra-high strength steel plate U-shaped part.

Disclosure of Invention

The purpose of the invention is as follows: the invention aims to provide a finite element simulation method for multi-pass progressive bending forming of an ultra-high strength steel plate U-shaped part; and predicting the bending amount and the springback amount of each pass in the multi-pass progressive bending forming process of the ultra-high strength steel plate U-shaped part.

The technical scheme is as follows: the invention relates to a finite element simulation method for multi-pass progressive bending forming of an ultra-high strength steel plate U-shaped part, which comprises the following specific operation steps of:

(1) establishing a constitutive model of the ultrahigh-strength steel material;

(2) designing the bending pass and the bending amount of each pass of the ultrahigh-strength steel according to the size of the U-shaped part;

(3) establishing a bending forming finite element model of the first-pass ultrahigh-strength steel plate U-shaped part;

(4) setting an analysis step according to the obtained constitutive model and the finite element model, simulating a first-pass bending forming process by adopting a dynamic display algorithm, and calculating stress, strain, force and deformation in the bending process;

(5) establishing a springback finite element model after bending and forming a first-time ultrahigh-strength steel plate U-shaped piece by adopting the restarting function of ABAQUS;

(6) simulating the springback process after the first bending forming by adopting a static implicit algorithm, and calculating stress, strain, force and deformation in the springback process;

(7) adopting the restarting function of ABAQUS, repeating the steps (3) to (6), and respectively calculating the stress, strain, force and deformation after bending forming and rebounding of other passes;

(8) and (3) comparing simulation results according to the size of the U-shaped part product, and verifying the bending pass designed in the step (2) and the bending amount of each pass.

Further, in the step (1), the specific operation steps of establishing the constitutive model of the ultra-high strength steel material are as follows:

(1.1) cutting and processing a tensile sample from the rolled-heat-treated ultrahigh-strength steel plate along a parallel rolling direction, a vertical rolling direction and a direction forming an angle of 45 degrees with the rolling direction respectively;

(1.2) carrying out unidirectional tensile test on tensile samples in different directions, recording deformation during tensile by adopting an extensometer, obtaining a force-deformation curve during tensile, and obtaining a tensile true stress-true strain curve of the tensile sample in each direction according to the curve, the sectional area of the sample and the gauge length of the extensometer;

(1.3) obtaining the plastic strain ratio of the material in each direction, the Hill48 anisotropic yield criterion parameters and the A-F nonlinear follow-up strengthening model parameters according to the tensile true stress-true strain curve of the tensile sample in each direction;

and (1.4) writing the obtained parameters into a program file based on ABAQUS software secondary development.

Further, in the step (3), the specific operation steps of establishing the bending forming finite element model of the first-pass ultrahigh-strength steel plate U-shaped part are as follows:

(3.1) establishing an ultrahigh-strength steel plate, a bending male die and a bending female die solid model by using ABAQUS software;

(3.2) carrying out meshing on the entity model, and assembling and positioning the ultrahigh-strength steel plate, the bending male die and the bending female die;

(3.3) respectively defining the contact conditions between the ultrahigh-strength steel plate and the bending male die and between the ultrahigh-strength steel plate and the bending female die, defining the condition of fixing the boundary of the female die, and defining the downward distance of the male die, namely the bending amount;

and (3.4) writing the secondarily developed program file completed in the step (1.4) into ABAQUS software.

Further, in the step (5), the specific operation steps of establishing the springback finite element model after the first-pass ultrahigh-strength steel plate U-shaped part is bent and formed are as follows:

(5.1) eliminating the definition of the contact conditions among the ultrahigh-strength steel plate, the bending male die and the bending female die in the step (3.3);

(5.2) defining displacement boundary conditions of the bent ultrahigh-strength steel plate;

and (5.3) taking the stress and the strain after the first bending as initial conditions for calculating the resilience.

Has the advantages that: compared with the prior art, the finite element simulation method for multi-pass progressive bending forming of the ultra-high strength steel plate U-shaped part, provided by the invention, can be used for predicting the bending amount and the springback amount of each pass of bending forming, and provides a basis for formulating a multi-pass progressive bending forming process of the ultra-high strength steel plate U-shaped part.

Drawings

FIG. 1 is a flow chart of the operation of the present invention;

FIG. 2 is a schematic diagram of the bending process of the female die, the male die and the ultrahigh-strength steel plate in the invention;

fig. 3 is a schematic view of an ultra-high strength steel plate U-shaped member in the present invention.

Detailed Description

The invention is further described below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.

As shown in fig. 1, the finite element simulation method for multi-pass progressive bending forming of the ultra-high strength steel plate U-shaped part, provided by the invention, comprises the following specific operation steps:

(1) establishing a constitutive model of the ultrahigh-strength steel material;

(2) designing the bending pass and the bending amount of each pass of the ultrahigh-strength steel according to the size requirement of the U-shaped part;

(3) establishing a bending forming finite element model of the first-pass ultrahigh-strength steel plate U-shaped part;

(4) setting a proper analysis step according to the obtained constitutive model in the step (1) and the finite element model in the step (3), simulating a first-time bending forming process by adopting a dynamic display algorithm, and calculating stress, strain, force, deformation and the like in the bending process;

(5) establishing a springback finite element model after bending and forming a first-time ultrahigh-strength steel plate U-shaped piece by adopting the restarting function of ABAQUS;

(6) simulating the springback process after the first bending forming by adopting a static implicit algorithm, and calculating stress, strain, force, deformation and the like in the springback process;

(7) adopting the restarting function of ABAQUS, repeating the steps (3) to (6), and respectively calculating the stress, strain, force, deformation and the like after bending forming and rebounding of other passes;

(8) and (3) comparing simulation results according to the size requirements of the U-shaped part product, and verifying the bending pass and the bending amount of each pass designed in the step (2).

Further, in the step (1), the specific operation steps of establishing the constitutive model of the ultra-high strength steel material are as follows:

(1.1) cutting and processing a tensile sample from the rolled-heat-treated ultrahigh-strength steel plate along a parallel rolling direction, a vertical rolling direction and a direction forming an angle of 45 degrees with the rolling direction respectively;

(1.2) carrying out unidirectional tensile test on tensile samples in different directions, recording deformation during tensile by adopting an extensometer, obtaining a force-deformation curve during tensile, and obtaining a tensile true stress-true strain curve of the tensile sample in each direction according to the curve, the sectional area of the sample and the gauge length of the extensometer;

(1.3) obtaining the plastic strain ratio of the material in each direction, the Hill48 anisotropic yield criterion parameters and the A-F nonlinear follow-up strengthening model parameters according to the tensile true stress-true strain curve of the tensile sample in each direction;

(1.4) writing the parameters obtained in the step (1.3) into a program file based on ABAQUS software secondary development.

Further, in the step (3), the specific operation steps of establishing the bending forming finite element model of the first-pass ultrahigh-strength steel plate U-shaped part are as follows:

(3.1) establishing an ultrahigh-strength steel plate, a bending male die and a bending female die solid model by using ABAQUS software;

(3.2) carrying out meshing on the entity model, and assembling and positioning the ultrahigh-strength steel plate, the bending male die and the bending female die;

(3.3) respectively defining the contact conditions between the ultrahigh-strength steel plate and the bending male die and between the ultrahigh-strength steel plate and the bending female die, defining the condition of fixing the boundary of the female die, and defining the downward distance of the male die, namely the bending amount;

and (3.4) writing the secondarily developed program file completed in the step (1.4) into ABAQUS software.

Further, in the step (5), the specific operation steps of establishing the springback finite element model after the first-pass ultrahigh-strength steel plate U-shaped part is bent and formed are as follows:

(5.1) eliminating the definition of the contact conditions among the ultrahigh-strength steel plate, the bending male die and the bending female die in the step (3.3);

(5.2) defining displacement boundary conditions of the bent ultrahigh-strength steel plate;

and (5.3) taking the stress and the strain after the first bending as initial conditions for calculating the resilience.

The above description is only for the purpose of facilitating an understanding of the core concepts of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present invention.