CN112364549B - Method for establishing rolling variable-thickness plate forming limit field - Google Patents
Method for establishing rolling variable-thickness plate forming limit field Download PDFInfo
- Publication number
- CN112364549B CN112364549B CN202011418304.1A CN202011418304A CN112364549B CN 112364549 B CN112364549 B CN 112364549B CN 202011418304 A CN202011418304 A CN 202011418304A CN 112364549 B CN112364549 B CN 112364549B
- Authority
- CN
- China
- Prior art keywords
- thickness
- forming limit
- strain value
- field
- plate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/20—Design optimisation, verification or simulation
- G06F30/23—Design optimisation, verification or simulation using finite element methods [FEM] or finite difference methods [FDM]
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T17/00—Three dimensional [3D] modelling, e.g. data description of 3D objects
- G06T17/20—Finite element generation, e.g. wire-frame surface description, tesselation
-
- G—PHYSICS
- G16—INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR SPECIFIC APPLICATION FIELDS
- G16C—COMPUTATIONAL CHEMISTRY; CHEMOINFORMATICS; COMPUTATIONAL MATERIALS SCIENCE
- G16C60/00—Computational materials science, i.e. ICT specially adapted for investigating the physical or chemical properties of materials or phenomena associated with their design, synthesis, processing, characterisation or utilisation
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2111/00—Details relating to CAD techniques
- G06F2111/10—Numerical modelling
Landscapes
- Engineering & Computer Science (AREA)
- Theoretical Computer Science (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Computing Systems (AREA)
- Geometry (AREA)
- Evolutionary Computation (AREA)
- General Engineering & Computer Science (AREA)
- Computer Graphics (AREA)
- Software Systems (AREA)
- Computer Hardware Design (AREA)
- Life Sciences & Earth Sciences (AREA)
- Bioinformatics & Cheminformatics (AREA)
- Bioinformatics & Computational Biology (AREA)
- Shaping Metal By Deep-Drawing, Or The Like (AREA)
Abstract
The invention discloses a method for establishing a forming limit field of a rolled variable-thickness plate, which is applied to the technical field of forming processing and comprises the following specific steps: dividing the differential thick plate by adopting a partition discrete method, and fitting a primary strain value and a secondary strain value of a forming limit point under each thickness by using a least square method to obtain a forming limit curve under the thickness; after forming limit curves under all thicknesses are obtained, the secondary strain value under each thickness is utilized to obtain the corresponding primary strain value, the secondary strain value is x, the thickness is y, the primary strain value is z, and the thickness is an interpolation variable to obtain a formula of forming limit field. The invention realizes the prediction and assessment of the forming limit of the differential thick plate.
Description
Technical Field
The invention relates to the technical field of forming processing, in particular to a method for establishing a forming limit field of a rolled variable-thickness plate.
Background
Due to the difference of rolling reduction in different areas of the differential thick plate in the rolling process, the material properties of each part of the differential thick plate are different, the thickness is also nonuniform, and the problem of prediction and judgment of the forming limit of the differential thick plate when the differential thick plate is formed at room temperature cannot be solved by the existing research results, so that the problem is also a big bottleneck in the actual application process of the differential thick plate.
Generally, methods of establishing forming limits are largely divided into three categories: experimental determination, theoretical calculation and numerical simulation. When the forming limit curve of the uniform equal-thickness plate is determined by a test method, the hydraulic bulging test, the rigid punch bulging test, the biaxial stretching test and the like are widely applied, and a series of accurate results are obtained. However, since the limit strain test has a complicated measurement process and is greatly influenced by test conditions and human factors, a large number of forming limit theory calculation models and semi-empirical formulas have been proposed by the scholars in the past and verified by tests, such as a necking theory assuming uniform sheet material, an M-K theory considering non-uniformity of sheet material, and a Keeler-Brazier empirical formula. Generally, the basic performance parameters of the plate can be obtained by a simple test method, and a forming limit curve with higher precision can be calculated by utilizing a theoretical formula. However, the biggest problem of the theoretical calculation method is that some assumptions and simplification are made before the final theoretical formula is obtained, so that certain differences exist between the theoretical formula and the actual working conditions, and therefore, the theoretical formula generally only can carry out qualitative analysis on the problem, but the numerical simulation can take various factors and conditions into account as much as possible, so that the theoretical calculation method is closer to the actual production process, and can carry out more accurate quantitative analysis on the forming limit problem. The analysis is mainly aimed at common plates with equal thickness, but the establishment and use methods of forming curves of rolling differential plates are not reported yet.
Therefore, it would be a matter of great need for those skilled in the art to provide a three-dimensional forming limit field establishment method for prediction and assessment of forming limits of differential slabs.
Disclosure of Invention
In view of the above, the invention provides a method for establishing a forming limit field of a rolled variable-thickness plate. And drawing the obtained limit points on a rectangular coordinate system taking the primary strain and the secondary strain as the longitudinal coordinate and the transverse coordinate to obtain a complete forming limit curve, and comparing the complete forming limit curve with the curve obtained by the theoretical formula to verify the correctness of the forming limit curve. And then the differential thick plate is scattered into a plurality of equal thick plate assemblies, and the forming limit curve of each discrete plate is solved. And then interpolating the thickness of the plate material by a plurality of discrete forming limit curves to construct the three-dimensional forming limit curved surface of the differential plate. And finally, the forming limit of the differential plate cylindrical part is predicted through the forming limit field, so that the accuracy and the practicability of the forming limit field constructed by the invention are verified.
In order to achieve the above purpose, the invention adopts the following technical scheme:
the method for establishing the forming limit field of the rolled variable-thickness plate comprises the following specific steps:
dividing the differential thick plate by adopting a partition discrete method, and fitting a primary strain value and a secondary strain value of a forming limit point under each thickness by using a least square method to obtain a forming limit curve under the thickness;
after forming limit curves under all thicknesses are obtained, the secondary strain value under each thickness is utilized to obtain the corresponding primary strain value, the secondary strain value is x, the thickness is y, the primary strain value is z, and the thickness is an interpolation variable to obtain a formula of forming limit field.
Preferably, in the above method for establishing a forming limit field of a rolled variable thickness plate, a forming limit curve of the plate with equal thickness is obtained by fitting by least square method.
Preferably, in the above method for establishing a forming limit field of a rolled variable thickness sheet, the secondary strain value at each thickness is equally divided into 40 parts at intervals of 0.01 from-0.2 to 0.2, and the corresponding primary strain value is obtained; and taking the secondary strain value as x, the thickness as y, the main strain value as z, and the thickness as an interpolation variable to obtain the expression of the forming limit field.
Preferably, in the above method for establishing a forming limit field of a rolled variable thickness plate, the forming limit field has the expression:
wherein formula (1) is a formula of a forming limit field when the secondary strain value is less than 0, formula (2) is a formula of a forming limit field when the secondary strain value is greater than 0, wherein ε 1 To the forming limitThe principal strain value of the field, ε 2 The value of the secondary strain of the forming limit field, η is the thickness value.
Compared with the prior art, the invention discloses a method for establishing a forming limit field of a rolled variable-thickness plate, which comprises the steps of adopting a hemispherical male die bulging numerical simulation method, simulating different loading paths by changing the length-width ratio of a test piece to obtain forming limits of the plate in different strain states, drawing the obtained limit points on a rectangular coordinate system taking principal strain and secondary strain as longitudinal and transverse coordinates to obtain a complete forming limit curve, and comparing the curve with a curve obtained by a theoretical formula to verify the correctness of the curve. And then the differential thick plate is scattered into a plurality of equal thick plate assemblies, and the forming limit curve of each discrete plate is solved. And then interpolating the thickness of the plate material by a plurality of discrete forming limit curves to construct a three-dimensional forming limit curve of the differential thick plate, so as to realize the prediction and evaluation of the forming limit of the differential thick plate.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only embodiments of the present invention, and that other drawings can be obtained according to the provided drawings without inventive effort for a person skilled in the art.
FIG. 1 is a three-dimensional finite element model diagram in an embodiment of the present invention;
FIGS. 2 (a) -2 (f) are schematic diagrams of test pieces 1-6 according to embodiments of the present invention;
FIG. 3 is a diagram illustrating three different ways of determining sheet forming limits in an embodiment of the present invention;
FIG. 4 is a schematic diagram of a forming limit field in an embodiment of the invention;
FIG. 5 is a schematic diagram of a validated formation-limiting field in an embodiment of the present invention;
fig. 6 is a flow chart of the method of the present invention.
Detailed Description
The following description of the technical solutions in the embodiments of the present invention will be clear and complete, and it is obvious that the described embodiments are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
The embodiment of the invention discloses a method for establishing a forming limit field of a rolled variable-thickness plate, which comprises the following specific steps of:
dividing the differential thick plate by adopting a partition discrete method, and fitting a primary strain value and a secondary strain value of a forming limit point under each thickness by using a least square method to obtain a forming limit curve under the thickness;
after forming limit curves under all thicknesses are obtained, the secondary strain value under each thickness is utilized to obtain the corresponding primary strain value, the secondary strain value is x, the thickness is y, the primary strain value is z, and the thickness is an interpolation variable to obtain a formula of forming limit field.
In order to further optimize the technical scheme, a forming limit curve of the equal-thickness plate is obtained by fitting with a least square method.
Furthermore, dynaform software is adopted to complete hemispherical male die numerical simulation, and a male die, a female die with draw beads and a blank holder required by simulation are established in Solidworks. The function of the draw beads is to increase the feeding resistance, prevent the material from flowing into the female die during bulging, and finish forming as much as possible by thinning the material in the bulging area. The built model is shown in fig. 1, and is sequentially provided with a male die, a blank holder and a female die from top to bottom. The dimensions of each die were set according to GB/T15825.8-1995 method for sheet metal formability and test, as shown in Table 1.
Table 1 hemispherical bulging test model dimensions
The post-treatment frame number is 150, the blank holder force is 150000N, the die gap is 1.1 times of the thickness of the plate, the stamping speed is 1000mm/s, and the punch stroke is 70mm. The friction coefficient between the male die and the plate is 0.12, and the friction coefficient between the female die, the blank holder and the plate is set to be 0.3.
Six different samples were used, the shape and size of which are shown in fig. 2 (a) - (f). The lengths of the plates are 180mm, and the widths of the central positions are 30mm,60mm,90mm,120mm,150mm and 180mm respectively. They are numbered 1-6, respectively. No. 1 represents a unidirectional tensile stress state, no. 3 represents a plane strain state, no. 6 represents an equal double tensile stress state, and the remaining No. 2,4,5 represent intermediate states.
The bulging simulation was performed on 6 typical samples, and the post-treatment results were analyzed, and the forming limit diagram used at this time was established based on the Keeler theory. A frame in which the specimen was just broken was found, and the main strain and the sub strain values of the breaking point were obtained as shown in table 2.
TABLE 2 Primary and secondary strain values for forming limit points for samples of different thicknesses
The first step in obtaining the forming limit graph is to find the intersection point of the forming limit curve and the main strain axis, i.e. FLD 0 In this embodiment, the value is 0.3385 obtained by averaging the data with the secondary strain within plus or minus 10%, and the ultimate strain points of the obtained 6 typical samples are respectively processed by using a lagrangian polynomial interpolation method and a least square method, so as to obtain a forming limit curve of the sheet, and fig. 3 shows a comparison of the two processing methods and the forming limit curve obtained by the Keeler theory.
It can be seen from fig. 3 that the curve obtained using the least square method is similar in shape to the curve obtained using the lagrangian interpolation method, and differs from the curve obtained by the theoretical formula, but the general trend is substantially consistent. Further, the least squares method substantially coincides with the theoretical calculation value in the range of-0.15 to-0.1 in the portion where the secondary strain value is smaller than 0, whereas the lagrangian interpolation method is greatly different from the theoretical calculation value. In the section-0.1 to 0, both have a certain deviation from the theoretical calculated forming limit curve, and the lagrangian interpolation gives a greater deviation in the results. For the portion where the secondary strain value is greater than 0, the results obtained using the lagrangian interpolation method and the least square method in the interval of 0 to 0.1 are both greater than those obtained by the and equation calculation, and the results obtained by the least square method are larger. In the interval of 0.1 to 1.5, both are lower than the theoretical calculation result, and the least square method is closer to the theoretical calculation result. In summary, the least square method is closer to the theoretical value than the forming limit curve obtained by the Lagrange interpolation method, so that the forming limit curve of the equal-thickness plate is fitted by the least square method.
In order to further optimize the technical scheme, the forming performance of different plate thickness positions of the differential thick plate depends on the thickness and material properties of the plate, and in order to describe the material performance and thickness change of the differential thick plate in numerical simulation, a zoned discrete method is adopted, namely, a transition zone of the differential thick plate with the thickness of 1.2mm/2.0mm is divided into an assembly formed by equal-thickness plates with the thickness of 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm and 2.0 mm. The equal thickness plate at each thickness was analyzed to obtain its formability.
First, the principal and secondary strain values of the forming limit point at each thickness were fitted by the least square method to obtain a forming limit curve at that thickness, and the fitting result is shown in table 3.
TABLE 3 fitting formation limit curve coefficients
After forming limit curves under all thicknesses are obtained, the secondary strain value under each thickness is equally divided into 40 parts at intervals of 0.01 from-0.2 to 0.2, the corresponding primary strain value is obtained, the secondary strain value is x, the thickness is y, the primary strain value is z, the thickness is interpolation variable, a forming limit field shown in figure 4 is obtained, and the expression of the forming limit field is a common formulaFormula (1) and formula (2), wherein formula (1) is a formula of a forming limit field when the secondary strain value is less than 0, formula (2) is a formula of a forming limit field when the secondary strain value is greater than 0, wherein ε 1 For shaping the principal strain value of the limiting field ε 2 The value of the secondary strain of the forming limit field, η is the thickness value.
Forming limit field verification:
the cylindrical part is a typical part in a drawing forming process, and the embodiment of the invention adopts drawing forming of the cylindrical part as an example, and verifies the accuracy of a forming limit field of the differential thick plate.
Because the thicknesses of the plates in different areas of the rolled differential plate are different, in order to enable the blank holder to press the plates to prevent wrinkling, the embodiment of the invention adopts the block blank holder to carry out blank holder, and different blank holder forces are set to ensure that the blank holder presses the plates. Besides the blank holder, the male die is also different from the male die used in the stamping of the equal-thickness plate, the shape of the male die is matched with that of the plate, namely, a corresponding transition area is also arranged on the male die, and simultaneously, round corners with different sizes are arranged on the thin side and the thick side. In summary, in the embodiment of the invention, the diameter of the male die is 100mm, the size of the round angle of the thick side is 5.2mm, and the size of the round angle of the thin side is 6.3mm; the diameter of the female die is 104mm, the size of the round angle is 6mm, the diameter of the flange of the female die is 200mm, the thin side of the differential thickness plate is 1.2mm, the thick side is 2mm, and the diameter of the set plate is 200mm. The thin side blank holder force is 40KN, the thick side blank holder force is 20KN, the descending speed of the male die is 2000mm/s, the stroke of the male die is 40mm, and the friction coefficient between the male die and the plate material and between the female die and the blank holder is 0.125.
The post-processing result shows that the 41 st frame starts to crack, the main strain value of one crack unit is read to be 0.413, the secondary strain value is read to be 0.015, the thickness corresponding to the crack unit is found to be 1.8mm, the main strain, the secondary strain and the thickness in the obtained result are rewritten into a coordinate format (0.015,1.8,0.413), the main strain value, the secondary strain value and the thickness corresponding to the main strain value are obtained in the same way, and the position relation between the coordinate point and the forming limit field is obtained as shown in fig. 5. The coordinate values of the fracture points are taken into the formulas (1) and (2), and the obtained calculation results are shown in table 4.
Table 4 results of the verification
The coordinate points of the rupture cells are above the forming limit field, i.e. the rupture has occurred, and the forming limit field is predicted more accurately, and the deviation from the theoretical value is only 4.03% at maximum, as can be seen from fig. 5 and table 4.
In order to further prove the accuracy of the forming limit field constructed by the embodiment of the invention on the forming limit prediction of the differential plate, the parameters of the forming limit curve corresponding to the unit 1 with the thickness of 1.879mm are extracted, and are reversely input into Dynaform, and the same parameters are set for simulation. And checking the stamping result in the post-processing to find out a key frame when the cell number 1 breaks. Simulation of a forming limit diagram when a No. 1 unit is broken shows that the breaking occurs at 41 frames, and the obtained drawing depth is 35.431mm; in the simulation of the forming limit diagram of Dynaform, cracking occurs in 41 frames, the obtained drawing depth is 35.856mm, the relative error of the drawing depth is only 1.19% in the two cases, the matching degree is good, and the prediction of the forming limit field of the differential thickness plate is relatively conservative in the comprehensive drawing depth result and the view of fig. 5 and table 4, namely, the forming limit field obtained by the embodiment of the invention is feasible in predicting the cracking problem of the plate.
In the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different point from other embodiments, and identical and similar parts between the embodiments are all enough to refer to each other.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (3)
1. The method for establishing the forming limit field of the rolled variable-thickness plate is characterized by comprising the following specific steps of:
dividing the differential thick plate by adopting a partition discrete method, and fitting a primary strain value and a secondary strain value of a forming limit point under each thickness by using a least square method to obtain a forming limit curve under the thickness;
after forming limit curves under all thicknesses are obtained, the secondary strain value under each thickness is utilized to obtain the corresponding main strain value, the secondary strain value is x, the thickness is y, the main strain value is z, and the thickness is an interpolation variable to obtain a formula of forming limit field;
the expression of the forming limit field is:
wherein formula (1) is a formula of a forming limit field when the secondary strain value is less than 0, formula (2) is a formula of a forming limit field when the secondary strain value is greater than 0, wherein ε 1 For shaping the principal strain value of the limiting field ε 2 The value of the secondary strain of the forming limit field, η is the thickness value.
2. The method for establishing the forming limit field of the rolled variable-thickness plate according to claim 1, wherein the forming limit curve of the thickness plate is obtained by using least square fitting.
3. The method for establishing a forming limit field of a rolled variable thickness sheet according to claim 1, wherein the secondary strain value at each thickness is equally divided into 40 parts at intervals of 0.01 from-0.2 to 0.2, and the corresponding primary strain value is obtained; and taking the secondary strain value as x, the thickness as y, the main strain value as z, and the thickness as an interpolation variable to obtain the expression of the forming limit field.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011418304.1A CN112364549B (en) | 2020-12-07 | 2020-12-07 | Method for establishing rolling variable-thickness plate forming limit field |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011418304.1A CN112364549B (en) | 2020-12-07 | 2020-12-07 | Method for establishing rolling variable-thickness plate forming limit field |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112364549A CN112364549A (en) | 2021-02-12 |
| CN112364549B true CN112364549B (en) | 2023-10-10 |
Family
ID=74535988
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011418304.1A Active CN112364549B (en) | 2020-12-07 | 2020-12-07 | Method for establishing rolling variable-thickness plate forming limit field |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112364549B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113642117B (en) * | 2021-07-01 | 2024-07-05 | 中铝材料应用研究院有限公司 | Prediction method for sheet metal forming limit diagram |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101354731A (en) * | 2008-02-19 | 2009-01-28 | 江苏大学 | Method for establishing and using difference thick laser assembly solder plate forming limit picture |
| CN103871098A (en) * | 2014-03-04 | 2014-06-18 | 湖南大学 | Method for constructing and using three-dimensional thermoforming limit diagram of VRB (Variable Thickness Rolled Blanks) |
| CN103870641A (en) * | 2014-03-04 | 2014-06-18 | 湖南大学 | Construction and using method of VRB (Variable Thickness Rolled Blank) forming limit stress diagram |
| CN105893708A (en) * | 2016-05-03 | 2016-08-24 | 湖南大学 | Method for use variable-thickness plate (VRB) three-dimensional thermoforming limit diagram |
-
2020
- 2020-12-07 CN CN202011418304.1A patent/CN112364549B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101354731A (en) * | 2008-02-19 | 2009-01-28 | 江苏大学 | Method for establishing and using difference thick laser assembly solder plate forming limit picture |
| CN103871098A (en) * | 2014-03-04 | 2014-06-18 | 湖南大学 | Method for constructing and using three-dimensional thermoforming limit diagram of VRB (Variable Thickness Rolled Blanks) |
| CN103870641A (en) * | 2014-03-04 | 2014-06-18 | 湖南大学 | Construction and using method of VRB (Variable Thickness Rolled Blank) forming limit stress diagram |
| CN105893708A (en) * | 2016-05-03 | 2016-08-24 | 湖南大学 | Method for use variable-thickness plate (VRB) three-dimensional thermoforming limit diagram |
Non-Patent Citations (3)
| Title |
|---|
| "板料成形极限曲线测试及 ＮＡＤＤＲＧ 模型预测";雷泽红等;《机械工程材料》;第102-106页 * |
| 应力-应变曲线形式对铝合金板料成形极限的影响;蔡中义;李丽;孙丽荣;孟凡响;;东北大学学报(自然科学版)(第03期);全文 * |
| 轧制差厚板变厚度区的应力应变关系表征;张思佳;刘相华;刘立忠;;机械工程学报(第18期);全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112364549A (en) | 2021-02-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103357734B (en) | Taper blank-holding and deep-drawing stamping method | |
| Hattalli et al. | Sheet metal forming processes–recent technological advances | |
| Padmanabhan et al. | Influence of process parameters on the deep drawing of stainless steel | |
| CN104765912B (en) | A kind of Robust Optimization method of aluminium sheet Sheet Metal Forming Technology | |
| CN106575314B (en) | Model setting method, molding simulation method, and method for manufacturing molding tool | |
| JP5630311B2 (en) | Method for predicting cracks in press molding and method for manufacturing pressed parts | |
| Volk et al. | Application of numerical simulations in deep-drawing process and holding system with segments’ inserts | |
| CN101811156A (en) | Method for obtaining molding resilience value of plate based on CAE (Computer Aided Engineering) analysis method | |
| CN112364549B (en) | Method for establishing rolling variable-thickness plate forming limit field | |
| Do et al. | Incremental forming of 3D structured aluminum sheet | |
| Dadgar Asl et al. | Fracture analysis on flexible roll forming process of anisotropic Al6061 using ductile fracture criteria and FLD | |
| CN103871098A (en) | Method for constructing and using three-dimensional thermoforming limit diagram of VRB (Variable Thickness Rolled Blanks) | |
| Allwood et al. | The technical and commercial potential of an incremental ring rolling process | |
| CN111069339B (en) | Step characteristic roll punching forming limit evaluation die and measuring method thereof | |
| CN103870641A (en) | Construction and using method of VRB (Variable Thickness Rolled Blank) forming limit stress diagram | |
| CN112257302B (en) | Method for constructing plate forming limit curve by adopting limit thickness | |
| CN201464303U (en) | Evaluating mold for testing sheet flanging property | |
| CN110765693A (en) | Design method of noble metal tantalum capacitor shell optimization die based on CAE simulation technology | |
| WANG et al. | Application of new VBHF optimization strategy to improve formability of automobile panels with aluminum alloy sheet | |
| CN104155177B (en) | A kind of super-high strength steel thin plate pre-punching process performance test sample and method of testing thereof | |
| KR102599529B1 (en) | Manufacturing method for tailgate extension using double drawing | |
| Fu et al. | Finite element simulation and experimental study of non-blank holder forward and backward composite deep drawing earing test | |
| JP7464176B1 (en) | Method, device and program for determining press-molded cracks, and method for manufacturing press-molded products | |
| JP2012011458A (en) | Crack determination method in press forming simulation, and method of manufacturing press formed component using the same | |
| Malikov et al. | Investigation of air bending of structured sheet metals by multistage FE simulation |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |