CN115600453A - Numerical simulation method for reducing laser bending forming boundary effect of metal sheet - Google Patents
Numerical simulation method for reducing laser bending forming boundary effect of metal sheet Download PDFInfo
- Publication number
- CN115600453A CN115600453A CN202211102871.5A CN202211102871A CN115600453A CN 115600453 A CN115600453 A CN 115600453A CN 202211102871 A CN202211102871 A CN 202211102871A CN 115600453 A CN115600453 A CN 115600453A
- Authority
- CN
- China
- Prior art keywords
- laser
- scanning
- boundary
- bending forming
- sheet
- 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.)
- Pending
Links
Images
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
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/10—Geometric CAD
- G06F30/17—Mechanical parametric or variational design
-
- 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
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2111/00—Details relating to CAD techniques
- G06F2111/04—Constraint-based CAD
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2111/00—Details relating to CAD techniques
- G06F2111/10—Numerical modelling
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2113/00—Details relating to the application field
- G06F2113/22—Moulding
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2113/00—Details relating to the application field
- G06F2113/24—Sheet material
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2119/00—Details relating to the type or aim of the analysis or the optimisation
- G06F2119/08—Thermal analysis or thermal optimisation
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2119/00—Details relating to the type or aim of the analysis or the optimisation
- G06F2119/14—Force analysis or force optimisation, e.g. static or dynamic forces
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Geometry (AREA)
- General Physics & Mathematics (AREA)
- Evolutionary Computation (AREA)
- General Engineering & Computer Science (AREA)
- Computer Hardware Design (AREA)
- Computational Mathematics (AREA)
- Mathematical Analysis (AREA)
- Mathematical Optimization (AREA)
- Pure & Applied Mathematics (AREA)
- Computer Graphics (AREA)
- Software Systems (AREA)
- Bending Of Plates, Rods, And Pipes (AREA)
Abstract
The invention provides a numerical simulation method for reducing the laser bending forming boundary effect of a metal sheet, which comprises the following steps of firstly establishing a geometric model of the metal sheet, then establishing a heat transfer analysis step, setting laser scanning process parameters and thermal boundary conditions, establishing a mobile laser heat source through a user self-defined subprogram, then carrying out local grid refinement on the whole model, calculating a temperature field of the metal sheet in laser bending forming under intermittent reciprocating scanning, setting a single-side fully-constrained boundary condition, importing a temperature field result under the intermittent reciprocating scanning, calculating a displacement field and deformation, and finally observing the deformation amount of the sheet and the size of the boundary effect under the intermittent reciprocating scanning. The invention can carry out numerical simulation on the deformation of the plate in the laser bending forming process, not only can obtain the deformation of the plate under given process parameters, but also can compare the boundary effect under different scanning strategies, thereby improving the dimensional accuracy of the laser bending forming.
Description
Technical Field
The invention belongs to the technical field of metal material thermal processing, and particularly relates to a numerical simulation method for reducing the laser bending forming boundary effect of a metal sheet.
Background
The application of the metal sheet forming part is more and more extensive in the fields of automobiles, ships, aerospace and the like. Therefore, the improvement of the forming technology of the metal plate has important research significance.
The traditional forming technology such as roll bending, die pressing and the like has many defects, such as the need of large-scale special equipment and the need of manufacturing a die, low forming efficiency and long period, is often only suitable for forming of large-batch parts, and is difficult to meet the production requirements of small-batch and customization. The laser bending forming is used as a non-contact forming mode, has the advantage of no need of a die, has high forming flexibility, can process parts with complex shapes, can shorten the production period and reduce the cost, and simultaneously ensures that a formed part has higher surface quality and better mechanical property.
The laser bending forming technology is characterized in that heat generated by laser acts on the surface of a metal to enable the metal to generate plastic deformation, when the laser beam irradiates a metal plate, the temperature of the upper surface of the plate is rapidly increased, the yield stress is reduced, the volume is expanded, bending opposite to the laser beam is generated, the temperature gradient in the thickness direction is reduced when the plate is cooled, the temperature of the upper surface is rapidly reduced, the volume is contracted, the temperature of the lower surface is increased, the volume is expanded, and finally bending facing the laser beam is generated. Due to the asymmetry of the laser scanning process, the temperature distribution of the plate from the scanning start end to the scanning end is not uniform, so that the plastic strain of the upper surface of the plate is not uniform, and the free end of the plate is not bent to the same extent along the scanning direction, which is called as a boundary effect of laser bending forming.
In recent years, more and more researchers begin to research the laser bending forming of the metal plate by means of finite element simulation, the research focuses on the relationship between laser process parameters and plate deformation, the influence of the thermal physical property parameters of the plate on the forming effect and the like, and little relates to how to reduce the boundary effect of the forming process by screening different scanning strategies through numerical simulation so as to improve the forming consistency and uniformity of the plate.
Based on the method, a numerical simulation method for reducing the boundary effect of laser bending forming of the metal sheet is provided.
Disclosure of Invention
The technical problem to be solved by the present invention is to solve the above-mentioned deficiencies of the prior art, and the metal plate has a boundary effect in the laser bending process, that is, the deformation of the free end of the plate is not uniform along the scanning direction. The traditional laser bending forming of metal plates mostly adopts a continuous reciprocating scanning strategy, the temperature of the plates in the scanning mode is continuously increased along with the scanning in the processing process, the non-uniformity of the surface temperature of the plates is further increased, and a larger boundary effect is generated after the processing is finished.
The invention provides a numerical simulation method for reducing the boundary effect of laser bending forming of a metal sheet, which obtains temperature field data and sheet deformation under an intermittent reciprocating scanning strategy through finite element simulation, and observes that the boundary effect is greatly reduced, thereby improving the dimensional accuracy of laser bending forming and solving the problems in the background technology.
In order to solve the technical problems, the invention adopts the technical scheme that: a numerical simulation method for reducing the boundary effect of laser bending forming of a metal sheet comprises the following steps:
the method comprises the steps of firstly establishing a geometric model of the sheet, then establishing a heat transfer analysis step, setting laser scanning process parameters and thermal boundary conditions, establishing a mobile laser heat source through a user-defined subprogram, then carrying out local grid refinement on the whole model, calculating a temperature field for laser bending forming of the sheet metal under intermittent reciprocating scanning, setting a single-side fully-constrained boundary condition, introducing a temperature field result under the intermittent reciprocating scanning, calculating a displacement field and deformation, and finally observing the deformation of the sheet metal and the size of the boundary effect under the intermittent reciprocating scanning.
Further, creating a sheet geometry model is to create a geometry model using a Part module in the finite element analysis software, abaqus CAE, with a thickness of less than 3mm, and then set material properties including density, thermal conductivity, specific heat capacity, elastic modulus, poisson's ratio, yield strength, and coefficient of thermal expansion.
Further, the established heat transfer analysis step comprises two heat transfer analysis steps of heating and cooling, the duration of the heating analysis step depends on the width of the scanning line, the scanning speed and the intermittent duration, and the duration of the cooling analysis step is set to be 5-15 min.
Further, thermal boundary conditions of the material are set, including laser absorption rate, emissivity and convective heat transfer coefficient, and a predefined field at room temperature is applied to the whole model.
Further, a mobile laser heat source is added on the upper surface of the model, the laser input heat follows Gaussian distribution, and the specific mathematical model is as follows:
wherein Q is the laser power,
eta is the absorption rate of the laser light,
R 0 is the radius of the light spot,
r is the distance from any point on the surface of the plate to the center of the light spot;
the loading of the mobile laser heat source is accomplished using a user-defined DFLUX subroutine of the Abaqus software.
Furthermore, the local grid refinement of the whole model is to set the grid size in the laser scanning area to be smaller than the spot radius, and to set the grid size in other areas to be 1 to 6 times of the grid size in the laser scanning area, and to set the grid cell type to be DC3D8, i.e. the type of the analysis of the heat transfer science.
Further, the intermittent reciprocating scanning means that the laser scans from one side of the plate to the other side along a scanning path, stops for a certain time, is cooled to room temperature and then scans along the opposite direction, the operation is carried out in a reciprocating mode in such a way, when analysis is submitted, an intermittent reciprocating scanning DFLUX subprogram is introduced, and a corresponding temperature field result is calculated.
Further, copying the model, modifying the type of the operation analysis step into statics analysis, setting a single-side full-constraint boundary condition to simulate single-side clamping under a real condition, changing the type of the grid unit into C3D8R, namely statics analysis, importing the calculated temperature field data into software, setting the temperature field data as a predefined temperature, and submitting the predefined temperature to software calculation.
Further, observing the deformation amount of the plate and the size of the boundary effect under the intermittent reciprocating scanning is to analyze the displacement field data of the thin plate after the operation is finished, and observe the bending degree and the deformation uniformity of the plate, namely the size of the boundary effect under the intermittent reciprocating scanning strategy.
Compared with the prior art, the invention has the following advantages:
temperature field data and plate deformation under the intermittent reciprocating scanning strategy are obtained through finite element simulation, and the boundary effect is observed to be greatly reduced, so that the size precision of laser bending forming is improved, the temperature field change under different scanning strategies can be obtained, the final deformation degree difference is explained, the cost is low, the calculation is convenient, experiments are not needed, the boundary effect size under different scanning strategies can be rapidly and visually compared, and the method is convenient and practical.
Drawings
FIG. 1 is a schematic flow chart of the method of the present invention.
FIG. 2 is a finite element model of a metal sheet after meshing according to an embodiment of the present invention.
FIG. 3 is a temperature-time curve of the temperature measurement point under intermittent reciprocating scanning in example 2 of the present invention.
FIG. 4 is a temperature-time curve of a temperature measurement point under continuous reciprocating scanning in example 3 of the present invention.
FIG. 5 is a finite element model after applying unilateral clamping boundary conditions in accordance with an embodiment of the present invention.
FIG. 6 is a Z-displacement cloud of a sheet under intermittent reciprocating scanning in example 2 of the present invention.
FIG. 7 is a Z-displacement cloud of a sheet under continuous reciprocal scanning in example 3 of the present invention.
FIG. 8 is a Z-displacement cloud of a sheet under intermittent reciprocating scanning in example 4 of the present invention.
FIG. 9 is a Z-displacement cloud of a sheet under continuous reciprocal scanning in example 5 of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
firstly, creating a sheet geometric model, namely creating the geometric model by using a Part module in finite element analysis software Abaqus CAE, wherein the thickness of the model is less than 3mm, and then setting material properties, wherein the material properties comprise density, thermal conductivity, specific heat capacity, elastic modulus, poisson ratio, yield strength and thermal expansion coefficient;
establishing a heat transfer analysis step, wherein the established heat transfer analysis step comprises a heating analysis step and a cooling analysis step, the duration of the heating analysis step depends on the width of a scanning line, the scanning speed and the intermittent duration, and the duration of the cooling analysis step is set to be 5-15 min;
setting laser scanning process parameters and thermal boundary conditions, setting thermal boundary conditions of materials, including laser absorptivity, radiation coefficient and convective heat transfer coefficient, and applying a predefined field with room temperature to the whole model;
a mobile laser heat source is established through a user-defined subprogram, the mobile laser heat source is added on the upper surface of a model, the laser input heat follows Gaussian distribution, and the specific mathematical model is as follows:
wherein Q is the laser power,
eta is the absorption rate of the laser light,
R 0 is the radius of the light spot,
r is the distance from any point on the surface of the plate to the center of the light spot;
the loading of the mobile laser heat source is accomplished using a user-defined DFLUX subroutine of the Abaqus software.
Then carrying out local grid refinement on the whole model, wherein the local grid refinement on the whole model is to set the grid size in a laser scanning area to be smaller than the radius of a light spot, increase the grid size in other areas to be 1-6 times of the grid size in the laser scanning area, and set the grid unit type as DC3D8, namely a heat transfer chemical analysis type;
calculating a temperature field formed by bending the metal plate by laser under intermittent reciprocating scanning, wherein the intermittent reciprocating scanning refers to that the laser scans from one side to the other side of the metal plate along a scanning path, stops for a certain time, and then scans along the opposite direction after the metal plate is cooled to room temperature, so that the operation is carried out repeatedly, and when the metal plate is submitted for analysis, an intermittent reciprocating scanning DFLUX subprogram is introduced, and a corresponding temperature field result is calculated;
copying a model, modifying the type of an operation analysis step into statics analysis, setting a single-side fully-constrained boundary condition to simulate single-side clamping under a real condition, changing the type of a grid unit into C3D8R, namely statics analysis, importing calculated temperature field data into software to set the temperature as a predefined temperature, submitting the predefined temperature to software calculation, calculating a displacement field and deformation, finally observing the deformation and the boundary effect of the plate under intermittent reciprocating scanning, analyzing the displacement field data of the plate after the operation is finished, and observing the bending degree and the deformation uniformity of the plate under an intermittent reciprocating scanning strategy, namely the size of the boundary effect.
Example 2, the material used in this example was a 5B70 aluminum alloy with a length, width and height of 100 x 50 x 2mm.
S1, creating a sheet geometric model, and setting material properties: a Part module in finite element software establishes a geometric model with the length, width and height of 100 multiplied by 50 multiplied by 2mm, and the density, the thermal conductivity, the specific heat capacity, the elastic modulus, the Poisson ratio, the yield strength and the thermal expansion coefficient of the 5B70 aluminum alloy are added.
S2, establishing a heat transfer analysis step, setting laser scanning process parameters and thermal boundary conditions, and establishing a mobile laser heat source through a user-defined subprogram:
the laser power P =300W is set,
the scanning speed v =5mm/s,
the spot radius R0=1mm,
the number of scans N =10 is,
the intermittent time of the intermittent scanning is 400s,
the laser absorptivity, emissivity and convective heat transfer coefficient are respectively eta =0.42, epsilon =0.7 and h = 25W/(m) 2 ·℃)。
S3, dividing grids, and carrying out grid refinement on a laser scanning area: as shown in fig. 2, the model is gridded, wherein the laser scanning area grid cell size is 0.5 × 0.5 × 0.5mm, and the other area grid cell size is 2 × 0.5 × 0.5mm, and the grid type is set to DC3D8.
S4, calculating a temperature field of laser bending forming of the metal plate: the calculation was automatically terminated when the temperature change was less than 0.01 c, with the heating analysis step duration of the intermittent reciprocating scan set to 3700s and the cooling analysis step duration set to 600 s. And (3) when the analysis is submitted, introducing an intermittent reciprocating scanning DFLUX subprogram, calculating a corresponding temperature field result, selecting a middle point of the upper surface of the model as a temperature measuring point, and obtaining a temperature-time curve as shown in figure 3.
S5, setting a unilateral clamping boundary condition, leading in a temperature field result under intermittent reciprocating scanning, and calculating a displacement field and deformation, wherein the clamping length is 10 mm: a finite element model with the addition of unilateral gripping boundary conditions is shown in fig. 5.
S6, observing the deformation of the plate and the size of the boundary effect in the intermittent reciprocating scanning mode:
fig. 6 is a Z-direction displacement cloud chart of the plate under the intermittent reciprocating scanning strategy, and it can be seen that the deformation uniformity of the free end of the plate under the intermittent reciprocating scanning is relatively good.
Example 3, this example is a comparative example to example 2, and is used to demonstrate that the boundary effect of laser bending forming of a metal sheet under an intermittent reciprocating scanning strategy is better than the boundary effect under a continuous reciprocating scanning strategy. The material used in this example was 5B70 aluminum alloy, 100X 50X 2mm in length, width and height.
S1, creating a sheet geometric model, and setting material properties: a Part module in finite element software establishes a geometric model with the length, width and height of 100 multiplied by 50 multiplied by 2mm, and the density, the thermal conductivity, the specific heat capacity, the elastic modulus, the Poisson ratio, the yield strength and the thermal expansion coefficient of 5B70 aluminum alloy are added.
S2, establishing a heat transfer analysis step, setting laser scanning process parameters and thermal boundary conditions, and establishing a mobile laser heat source through a user-defined subprogram:
the laser power P =300W is set,
the scanning speed v =5mm/s,
the spot radius R0=1mm,
the number of scans N =10 is,
the laser absorptivity, emissivity and convective heat transfer coefficient are respectively eta =0.42, epsilon =0.7 and h = 25W/(m) 2 ·℃)。
S3, dividing grids, and carrying out grid refinement on a laser scanning area: as shown in fig. 2, the model is gridded, wherein the laser scanning area grid cell size is 0.5 × 0.5 × 0.5mm, and the other area grid cell size is 2 × 0.5 × 0.5mm, and the grid type is set to DC3D8.
S4, calculating a temperature field of laser bending forming of the metal plate: the calculation was automatically terminated when the temperature change was less than 0.01 ℃ with the heating analysis step duration of the continuous reciprocating scan set to 100s and the cooling analysis step duration set to 600 s. When analysis is submitted, a continuous reciprocating scanning DFLUX subprogram is introduced, a corresponding temperature field result is calculated, the middle point of the upper surface of the model is selected as a temperature measuring point, and an obtained temperature-time curve is shown in figure 4.
S5, setting a unilateral clamping boundary condition, leading in a temperature field result under continuous reciprocating scanning, and calculating a displacement field and deformation, wherein the clamping length is 10 mm: a finite element model with the addition of unilateral gripping boundary conditions is shown in fig. 5.
S6, comparing the plate deformation and the boundary effect in different scanning modes:
fig. 7 is a Z-direction displacement cloud chart of the plate under the continuous reciprocating scanning strategy, and as can be seen in comparison with fig. 6, the bending deformation degree of the free end of the plate under the continuous reciprocating scanning is greater than that under the intermittent reciprocating scanning, while the deformation uniformity of the free end of the plate under the continuous reciprocating scanning is obviously inferior to that under the intermittent reciprocating scanning, which proves that the boundary effect of laser bending forming of the metal sheet can be effectively reduced through the intermittent reciprocating scanning.
Example 4
This example is a supplementary example of example 2, and is used to demonstrate that the boundary effect of the formed metal plate can still be improved by adopting the intermittent reciprocating scanning strategy under different process parameters, and the material used in this example is 5B70 aluminum alloy, and the length, width and height are 100 × 50 × 2mm.
S1, creating a sheet geometric model, and setting material properties: a Part module in finite element software establishes a geometric model with the length, width and height of 100 multiplied by 50 multiplied by 2mm, and the density, the thermal conductivity, the specific heat capacity, the elastic modulus, the Poisson ratio, the yield strength and the thermal expansion coefficient of the 5B70 aluminum alloy are added.
S2, establishing a heat transfer analysis step, setting laser scanning process parameters and thermal boundary conditions, and establishing a mobile laser heat source through a user-defined subprogram:
the laser power P =270W is set,
the scanning speed v =5mm/s,
the spot radius R0=1mm,
the number of scans N =10 is,
the intermittent time of the intermittent scanning is 400s,
the laser absorptivity, emissivity and convective heat transfer coefficient are respectively eta =0.42, epsilon =0.7 and h = 25W/(m) 2 ·℃)。
S3, dividing grids, and carrying out grid refinement on a laser scanning area: as shown in fig. 2, the model is gridded, wherein the laser scanning area grid cell size is 0.5 × 0.5 × 0.5mm, and the other area grid cell size is 2 × 0.5 × 0.5mm, and the grid type is set to DC3D8.
S4, calculating a temperature field of laser bending forming of the metal plate: the calculation was automatically terminated when the temperature change was less than 0.01 c, with the heating analysis step duration of the intermittent reciprocating scan set to 3700s and the cooling analysis step duration set to 600 s. And (4) introducing an intermittent reciprocating scanning DFLUX subprogram when the analysis is submitted, and calculating a corresponding temperature field result.
S5, setting unilateral clamping boundary conditions, wherein the clamping length is 10mm, importing a temperature field result under intermittent reciprocating scanning, and calculating a displacement field and deformation: a finite element model with the addition of unilateral gripping boundary conditions is shown in fig. 5.
S6, observing the deformation of the plate and the size of the boundary effect in the intermittent reciprocating scanning mode:
fig. 8 is a Z-direction displacement cloud chart of the plate under the intermittent reciprocating scanning strategy, and it can be seen that the deformation uniformity of the free end of the plate under the intermittent reciprocating scanning is relatively good.
Example 5
This example is a comparative example of example 4, and is used to demonstrate that the boundary effect of laser bending forming of a metal plate under an intermittent reciprocating scanning strategy is better than that under a continuous reciprocating scanning strategy under the same process parameters, and the material used in this example is 5B70 aluminum alloy, and the length, width and height are 100 × 50 × 2mm.
S1, creating a sheet geometric model, and setting material properties: a Part module in finite element software establishes a geometric model with the length, width and height of 100 multiplied by 50 multiplied by 2mm, and the density, the thermal conductivity, the specific heat capacity, the elastic modulus, the Poisson ratio, the yield strength and the thermal expansion coefficient of the 5B70 aluminum alloy are added.
S2, establishing a heat transfer analysis step, setting laser scanning process parameters and thermal boundary conditions, and establishing a mobile laser heat source through a user-defined subprogram:
the laser power P =270W is set,
the scanning speed v =5mm/s,
the spot radius R0=1mm,
the number of scans N =10 is,
the laser absorptivity, emissivity and convective heat transfer coefficient are respectively eta =0.42, epsilon =0.7 and h = 25W/(m) 2 ·℃)。
S3, dividing grids, and carrying out grid refinement on a laser scanning area: as shown in fig. 2, the model is gridded, wherein the laser scanning area grid cell size is 0.5 × 0.5 × 0.5mm, and the other area grid cell size is 2 × 0.5 × 0.5mm, and the grid type is set to DC3D8.
S4, calculating a temperature field of laser bending forming of the metal plate: the calculation was automatically terminated when the temperature change was less than 0.01 c, with the heating analysis step duration of the continuous reciprocating scan set to 100s and the cooling analysis step duration set to 600 s. And (4) when the analysis is submitted, introducing a continuous reciprocating scanning DFLUX subprogram, and calculating a corresponding temperature field result.
S5, setting unilateral clamping boundary conditions, wherein the clamping length is 10mm, importing a temperature field result under continuous reciprocating scanning, and calculating a displacement field and deformation: a finite element model with the addition of unilateral gripping boundary conditions is shown in fig. 5.
S6, comparing the plate deformation and the boundary effect in different scanning modes:
fig. 9 is a Z-direction displacement cloud chart of the plate under the continuous reciprocating scanning strategy, and as can be seen in comparison with fig. 8, the bending deformation degree of the free end of the plate under the continuous reciprocating scanning is greater than that under the intermittent reciprocating scanning, while the deformation uniformity of the free end of the plate under the continuous reciprocating scanning is obviously inferior to that under the intermittent reciprocating scanning, that is, the boundary effect of laser bending forming of the metal sheet can be effectively reduced through the intermittent reciprocating scanning under the same process parameters.
It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.
Claims (9)
1. A numerical simulation method for reducing the boundary effect of laser bending forming of a metal sheet is characterized by comprising the following steps:
the method comprises the steps of firstly establishing a geometric model of the sheet, then establishing a heat transfer analysis step, setting laser scanning process parameters and thermal boundary conditions, establishing a mobile laser heat source through a user-defined subprogram, then carrying out local grid refinement on the whole model, calculating a temperature field for laser bending forming of the sheet metal under intermittent reciprocating scanning, setting a single-side fully-constrained boundary condition, introducing a temperature field result under the intermittent reciprocating scanning, calculating a displacement field and deformation, and finally observing the deformation of the sheet metal and the size of the boundary effect under the intermittent reciprocating scanning.
2. A numerical simulation method for reducing sheet metal laser bend forming boundary effects in accordance with claim 1, wherein creating a sheet geometry model is creating a geometry model using a Part module in the finite element analysis software Abaqus CAE, the thickness of the model being less than 3mm, and then setting material properties, the material properties including density, thermal conductivity, specific heat capacity, elastic modulus, poisson's ratio, yield strength, and coefficient of thermal expansion.
3. The numerical simulation method for reducing the boundary effect of laser bending forming of metal sheets according to claim 1, wherein the established heat transfer analysis step comprises two heat transfer analysis steps of heating and cooling, the duration of the heating analysis step depends on the width of the scanning line, the scanning speed and the pause duration, and the duration of the cooling analysis step is set to be 5-15 min.
4. A numerical simulation method for reducing laser bend forming boundary effects of sheet metal according to claim 1, wherein thermal boundary conditions of the material are set, including laser absorption, emissivity and convective heat transfer, and a predefined field at room temperature is applied to the entire model.
5. The numerical simulation method for reducing the boundary effect of the laser bending forming of the metal sheet as claimed in claim 1, wherein a moving laser heat source is added on the upper surface of the model, the laser input heat follows Gaussian distribution, and the specific mathematical model is as follows:
wherein Q is the laser power,
eta is the absorption rate of the laser light,
R 0 is the radius of the light spot,
r is the distance from any point on the surface of the plate to the center of the light spot;
the loading of the mobile laser heat source is accomplished using a user-defined DFLUX subroutine of the Abaqus software.
6. The method as claimed in claim 1, wherein the local mesh refinement of the whole model is to set the mesh size in the laser scanning area to be smaller than the spot radius, and the mesh size in other areas to be 1-6 times larger than the mesh size in the laser scanning area, and the mesh cell type is set to be DC3D8, which is the type of thermal conductivity analysis.
7. A numerical simulation method for reducing boundary effects of laser bending forming of a metal sheet according to claim 1, wherein the intermittent reciprocating scanning means that the laser scans from one side to the other side of the metal sheet along a scanning path, stops for a certain period of time, cools to room temperature, and then scans in the opposite direction, and the intermittent reciprocating scanning DFLUX sub-program is introduced when the analysis is submitted, and the corresponding temperature field result is calculated.
8. The numerical simulation method for reducing the boundary effect of laser bending forming of the metal sheet as claimed in claim 1, wherein the model is copied, the type of the operation analysis step is modified into static analysis, a single-side full constraint boundary condition is set to simulate single-side clamping under real conditions, the type of the grid unit is changed into C3D8R, the static analysis is carried out, the calculated temperature field data is imported into software to be set to a predefined temperature, and the software is submitted to calculation.
9. The numerical simulation method for reducing the boundary effect of laser bending forming of metal sheets as claimed in claim 1, wherein the observation of the deformation amount of the sheet material and the size of the boundary effect under the intermittent reciprocating scanning is to analyze the displacement field data of the sheet material after the operation is finished, and observe the bending degree and the deformation uniformity of the sheet material under the intermittent reciprocating scanning strategy, namely the size of the boundary effect.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211102871.5A CN115600453A (en) | 2022-09-09 | 2022-09-09 | Numerical simulation method for reducing laser bending forming boundary effect of metal sheet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211102871.5A CN115600453A (en) | 2022-09-09 | 2022-09-09 | Numerical simulation method for reducing laser bending forming boundary effect of metal sheet |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115600453A true CN115600453A (en) | 2023-01-13 |
Family
ID=84842331
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211102871.5A Pending CN115600453A (en) | 2022-09-09 | 2022-09-09 | Numerical simulation method for reducing laser bending forming boundary effect of metal sheet |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115600453A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116702321A (en) * | 2023-06-08 | 2023-09-05 | 大连海事大学 | Numerical calculation method for multi-flame-path forming of marine high-strength steel saddle plate |
-
2022
- 2022-09-09 CN CN202211102871.5A patent/CN115600453A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116702321A (en) * | 2023-06-08 | 2023-09-05 | 大连海事大学 | Numerical calculation method for multi-flame-path forming of marine high-strength steel saddle plate |
| CN116702321B (en) * | 2023-06-08 | 2024-01-30 | 大连海事大学 | Numerical calculation method for multi-flame-path forming of marine high-strength steel saddle plate |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Ding et al. | Thermo-mechanical analysis of Wire and Arc Additive Layer Manufacturing process on large multi-layer parts | |
| CN112380752B (en) | Method for improving welding process of metal sheet by predicting welding heat treatment value of metal sheet | |
| CN101722371B (en) | Laser welding weld joint/ heat affected zone shape and crystalline grain size prediction method, and device for relizing the method | |
| CN115600453A (en) | Numerical simulation method for reducing laser bending forming boundary effect of metal sheet | |
| Fetene et al. | Numerical and experimental study on multi-pass laser bending of AH36 steel strips | |
| Lambiase et al. | An experimental investigation on passive water cooling in laser forming process | |
| CN111666663B (en) | SLM thermal stress rapid calculation method | |
| Hoseinpour Gollo et al. | Experimental and numerical study of spiral scan paths on cap laser forming | |
| CN112380677A (en) | Simulation method for temperature field in release agent for stripping carbon fiber material based on laser cleaning | |
| Modanloo et al. | Manufacturing of titanium bipolar plates using warm stamping process | |
| CN112172128A (en) | Method for rapidly optimizing polylactic acid fused deposition molding process based on dual-index orthogonal test combined with support vector machine | |
| CN111220648A (en) | Method for measuring interface heat exchange coefficient of aluminum alloy hot stamping process | |
| Nath et al. | Finite element analysis of AM30 magnesium alloy sheet in the laser bending process | |
| Dang et al. | Incremental bending of three-dimensional free form metal plates using minimum energy principle and model-less control | |
| Li et al. | A temperature-thread multiscale modeling approach for efficient prediction of part distortion by selective laser melting | |
| Shahabad et al. | Height prediction of dome-shaped products in laser forming process | |
| CN112906136A (en) | Method and system for predicting laser thermoforming deformation of hull plate | |
| CN109885946B (en) | Method for determining energy distribution of composite heat source and welding simulation method | |
| Bambach et al. | Mathematical modeling and optimization for powder-based additive manufacturing | |
| Shi et al. | An analytical model based on the similarity in temperature distributions in laser forming | |
| CN115130239A (en) | Mechanical property prediction method for metal additive manufacturing based on multi-scale modeling | |
| CN111859734A (en) | Optimization method for SLM additive manufacturing workpiece forming orientation | |
| Park et al. | Development of a Prediction System for 3D Printed Part Deformation | |
| CN107159746A (en) | A kind of aluminium alloy sheet laser bend forming process | |
| Tavakoli et al. | Optimization of circular scan path to produce bowl shapes in 3D laser forming process |
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 |