CN112100888B - Blade tenon tooth creep deep forming grinding residual stress prediction method - Google Patents
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- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims abstract description 34
- 239000000463 material Substances 0.000 claims abstract description 22
- 229910000601 superalloy Inorganic materials 0.000 claims abstract description 19
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- 239000007787 solid Substances 0.000 claims description 11
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Abstract
The invention relates to a method for predicting residual stress of slowly-advancing deep-cutting forming grinding of blade tenons, which belongs to the field of processing surface integrity research. Inputting blade tenon tooth material properties such as nickel-based superalloy and the like according to the requirements of finite element software, and selecting unit types and dividing grids. Then, blade tenon tooth creep deep-cutting forming grinding temperature finite element analysis and abrasive particle-workpiece interface contact pressure calculation are carried out. Finally, based on the thermal analysis and the contact pressure calculation result, performing thermal-stress coupling simulation calculation of the grinding residual stress, and checking the simulation result. Compared with the common finite element simulation method, the method has higher accuracy and precision.
Description
Technical field:
the invention provides a method for predicting residual stress of slowly-advancing deep-cutting forming grinding of blade tenon teeth, and belongs to the field of processing surface integrity research.
The background technology is as follows:
The turbine blade such as nickel-based superalloy is the most important hot end component of the aeroengine, and the tenon tooth with a complex shape is a key part for connecting the turbine blade and the turbine disc. Nickel-based superalloy belongs to a typical high-strength high-toughness difficult-to-process material, and creep forming grinding is a main method for efficiently and precisely processing the tenon tooth of a turbine blade. The tooth grinding surface/subsurface creates significant residual stresses due to the strong thermo-mechanical coupling that occurs during the grinding process.
Residual stresses on the work piece surface have a critical impact on the fatigue strength and service life of the blade dovetail. In recent years, grinding residual stress has become a key concern in the study of the integrity of machined surfaces, and accurate prediction thereof is a difficulty. The finite element simulation method is utilized to explore the residual stress distribution rule of the surface of the turbine blade tenon tooth such as nickel-based superalloy after creep deep cutting forming grinding processing, and the method is a main means for solving the problem of predicting the residual stress distribution of the surface of a grinding workpiece.
However, when the existing common finite element simulation method is used for predicting the residual stress of the blade tenon tooth grinding surfaces of nickel-based superalloy and the like, only the effect of grinding temperature is considered, the effect of contact interface pressure between abrasive particles and workpieces is not involved, the residual stress value obtained by finite element simulation calculation is very small, the maximum value is about 12Mpa, and the deviation from experimental measurement results is very large.
The invention comprises the following steps:
The invention aims to: the invention aims to solve the problems of low prediction precision and poor accuracy of the conventional common finite element simulation method, and aims to provide the prediction method for the residual stress of the blade tenon tooth creep deep forming grinding, which has high prediction precision and good accuracy.
The technical scheme is as follows: the invention is realized by the following technical scheme:
Firstly, a three-dimensional design software is applied to establish a three-dimensional model of a turbine blade tenon tooth, the generated three-dimensional model is stored in a solid model output format, and the solid model output format is imported into finite element software to establish a finite element model of the blade tenon tooth. Inputting blade tenon tooth material properties such as nickel-based superalloy and the like according to the requirements of finite element software, and selecting unit types and dividing grids. Then, blade tenon tooth creep deep-cutting forming grinding temperature finite element analysis and abrasive particle-workpiece interface contact pressure calculation are carried out. Finally, based on the thermal analysis and the contact pressure calculation result, thermal-stress coupling simulation calculation of the grinding residual stress is performed.
The grinding force loaded in the invention is converted into the contact pressure of the abrasive particle-workpiece interface by actually measuring the grinding force, and the forming process of the residual stress of the slow-entering deep-cutting formed grinding turbine blade tenon tooth is truly simulated, so that the grinding residual stress is obtained. The calculation of residual stress on the surface of the tenon tooth of the slowly-advancing deep-cutting grinding turbine blade based on the finite element simulation method is realized, and the operation flow and the steps are shown in figure 1.
The invention relates to a method for predicting residual stress of blade tenon tooth creep deep forming grinding, which comprises the following steps:
step one: finite element modeling for blade tenon tooth of aero-engine
The three-dimensional modeling of the blade tenon tooth of the aeroengine comprises the steps of applying three-dimensional design software to draw a two-dimensional sketch of the blade tenon tooth; based on the drawn sketch, a three-dimensional model of the blade tenon tooth is established by using a stretching command; measuring and acquiring related parameters for subsequent theoretical calculation, such as grinding arc area, grinding arc length, grinding width, blade tenon tooth geometric dimension and the like; and storing the generated three-dimensional model in a solid model output format, and importing the three-dimensional model into finite element simulation software.
The assignment of the material properties of the blade tenon tooth model comprises the step of inputting the material properties of the blade tenon tooth such as nickel-based superalloy and the like according to the requirements of finite element software. The material properties required for use in the thermal coupling simulation are density, specific heat capacity, thermal conductivity, coefficient of thermal expansion, elastic modulus, poisson's ratio, yield strength, tangential modulus.
The finite element mesh modeling of the blade tenon tooth model comprises unit type selection and mesh division. The grid cell type selection is divided into two types, namely a solid cell used in thermal analysis and a solid cell used in stress analysis; the grid division needs to meet the requirements of calculation amount and calculation precision, the grid division density is reasonably controlled, grid refinement is carried out on key parts, and the precision distribution of the grid division of the tenon teeth of the nickel-based superalloy blade is reasonably realized.
Step two: calculation of blade tenon tooth creep deep forming grinding temperature
The calculation of the grinding temperature of the slow-feeding deep-cutting forming grinding blade tenon tooth is to calculate the heat flow and the convection heat exchange quantity according to the grinding conditions on the basis of finite element modeling, apply the heat flow and the convection heat exchange quantity on the surface of a tenon tooth model, and perform the grinding temperature simulation calculation of the slow-feeding deep-cutting forming grinding blade tenon tooth to obtain the temperature distribution of the tenon tooth in the grinding process;
According to the temperature field heat source model, according to the shape of cutting thickness of a single abrasive particle, the cutting thickness of the single abrasive particle gradually increases from a cutting-in area to a cutting-out area, and a triangular heat source is selected, wherein the definition formula is as follows:
step three: calculation of abrasive grain-workpiece interface contact pressure
And calculating the contact pressure according to the number of the abrasive particles, the abrasive particle size and the grinding force based on a contact pressure action model between the effective abrasive particles in the grinding arc area and the workpiece material. The abrasive grain number is obtained by observing the surface of the grinding wheel, the abrasive grain size is an inherent parameter of the grinding wheel, and the grinding force is obtained by grinding test measurement.
Random cells are selected on the surface of the workpiece when the contact pressure of the abrasive grain-workpiece interface is applied, so as to simulate the interaction between the abrasive grain and the workpiece. Firstly, calculating the grinding force of the surface of a random unit, dividing the grinding force measured by an experiment by the number of abrasive particles in a grinding arc area to obtain the acting force born by each abrasive particle, wherein the acting force is represented by the following formula (3):
Wherein F n and F t are respectively tangential and normal grinding forces actually measured in a grinding experiment, N is the number of abrasive particles in a grinding arc area, and F n 'and F t' are respectively tangential and normal grinding forces applied to a single abrasive particle.
Since the grinding force should be applied in the form of pressure, then the force applied to the individual abrasive grains is divided by the force-bearing area a CS of the abrasive grains, and the contact pressure applied to the surface of the unit is finally obtained, as shown in formula (4):
Wherein P n and P t are the normal pressure and tangential pressure applied to the cell surface, respectively.
Step four: blade tenon tooth creep deep forming grinding residual stress simulation calculation
The simulation calculation of the grinding residual stress is to convert the result of thermal analysis into load and apply the calculated contact pressure on a blade tenon tooth model surface unit together on the basis of calculation of the blade tenon tooth creep deep forming grinding temperature and calculation of the contact pressure of an abrasive grain-workpiece interface, and to apply constraint on the tenon tooth model to carry out thermal coupling simulation between the grinding temperature and the contact pressure of the abrasive grain-workpiece interface. After the calculation is completed, hiding the uppermost unit (wherein the thickness of the unit is the grinding depth) of the blade tenon tooth, checking the simulation result, and finally obtaining the residual stress formed by the slow-feeding deep-cutting forming grinding of the blade tenon tooth and the distribution characteristics thereof.
The beneficial effects are that: the prediction method of the blade tenon tooth creep deep forming grinding residual stress based on the thermal coupling effect between the grinding temperature and the contact pressure of the abrasive particle-workpiece interface obviously improves the precision of the prediction result compared with the existing finite element simulation method.
Description of the drawings:
FIG. 1 is a flow chart of the method of the present invention.
FIG. 2 is a finite element model diagram of a turbine blade dovetail.
FIG. 3 is a grid view of a finite element model of a turbine blade dovetail.
Fig. 4 is a grinding force application diagram considering the abrasive grain-workpiece interface contact pressure.
FIG. 5 is a view of a turbine blade dovetail hidden uppermost unit.
Fig. 6 is a cloud of residual stress calculations taking into account the thermal coupling between grinding temperature and abrasive grain-workpiece interface contact pressure.
Fig. 7 is a cloud image of the results of the conventional method simulation calculation of the grinding surface residual stress.
FIG. 8 shows the results of actual measurement of residual stress.
The specific embodiment is as follows:
the invention will be described in further detail with reference to the drawings and examples.
Example 1
FIG. 1 is a flow chart of the method of the present invention. The invention will be described in detail with reference to fig. 1 from four aspects of finite element modeling of blade tenons of an aeroengine, calculation of the temperature of creep-feed deep-cut forming grinding of the blade tenons, calculation of the contact pressure of an abrasive particle-workpiece interface, and simulation calculation of residual stress of creep-feed deep-cut forming grinding of the blade tenons.
A blade tenon tooth creep deep forming grinding residual stress prediction method comprises the following steps:
Step one: three-dimensional modeling of blade tenon tooth
Firstly, applying three-dimensional mechanical design software (Solidworks), and drawing a two-dimensional sketch of a blade tenon by using a sketch tool according to the actual structure of the blade tenon, wherein the width and the height of the tenon are respectively 12mm and 6mm; based on the sketch, then using a stretching tool to build a three-dimensional model of the blade tooth, wherein the length of the tooth is 21mm; then, according to grinding process parameters (grinding wheel speed V s =35 m/s, workpiece feeding speed V w =300 mm/min, grinding depth a p =0.13 mm) and microcrystalline corundum grinding wheel diameter (400 mm), grinding arc length (l g =7.21 mm) is calculated according to formula (1):
Directly measuring related parameters in Solidworks software according to the grinding arc length so as to facilitate subsequent calculation and use, such as the grinding arc area (99.74 mm 2), the grinding width (14.6 mm 2) and the like; the generated three-dimensional model is stored in a solid model output format, namely a Parasolid (. X_t) format, and imported into Ansys software, as shown in FIG. 2.
And (3) assigning the material properties of the blade tenon tooth model, and inputting the material properties of the blade tenon tooth of the nickel-based single crystal superalloy DD6 according to the requirements in Ansys software. The material properties required for use in the thermal coupling simulation are density, specific heat capacity, thermal conductivity, coefficient of thermal expansion, elastic modulus, poisson's ratio, yield strength, tangential modulus, see in particular table 1.
TABLE 1 Material Properties of Nickel-base Single Crystal superalloy DD6 in the [001] direction
The finite element mesh modeling of the blade tenon tooth model comprises unit type selection and mesh division. The grid cell type selection is divided into two types, one is Solid 70 used in thermal analysis, the other is Solid 185 used in stress analysis, and the operation path of cell selection in Ansys is as follows: preprocessor ELEMENT TYPE selects entity (Solid) unit Solid 70 for application to thermal analysis (THERMAL MASS) in a pop-up dialog; the grid division needs to meet the requirements of calculation amount and calculation precision, the grid division density is reasonably controlled, grid refinement is carried out on key parts, and the precision reasonable distribution of the grid division of the blade tenon teeth of the DD6 nickel-base single crystal superalloy is realized. The operational path in Ansys is: the preprocessor| Meshing |mesh|volume Sweep is divided by adopting a hexahedral grid, and the hexahedral grid has the advantages of high precision and easy convergence of calculation, and the number of the hexahedral grid is smaller than that of the tetrahedral grid under the same grid size.
Finite element grid modeling is carried out on the nickel-based single crystal superalloy DD6 blade tenon tooth model according to the method, and the total number of nodes 384480 and the number of units 360148 in the finite element grid model in the model are obtained. The established finite element grid model of the blade tenon tooth of the DD6 blade of the nickel-based single crystal superalloy is shown in figure 3.
Step two: calculation of blade tenon tooth creep deep forming grinding temperature
The calculation of the blade tenon tooth creep-in deep forming grinding temperature is to simulate the grinding temperature in the process of the grinding wheel creep-in deep grinding of the nickel-based single crystal superalloy DD6 blade tenon tooth on the basis of three-dimensional modeling of the blade tenon tooth.
Firstly, the Thermal flow and the convection Heat exchange amount in the actual grinding process are loaded on the surface of a blade tenon workpiece, thermal analysis is carried out, the operation path in Ansys is solution|define loads|thermal Heat Flux & Convection, the size of Hear Flux is 150000W/m 2.C, the size of Convection is 6700W/m 2.C, and based on the idea of finite element dispersion, the small-step intermittent jump type moving load is adopted to simulate the processing process, namely, at different moments, constant Heat flow density is loaded in a grinding arc area, the grinding arc area is loaded in another area in the next period, and the result of the last calculation is taken as the initial condition of the analysis. In order to simultaneously consider the calculation amount and the calculation accuracy, the discrete steps adopted in the method are 400 steps, namely, the heat source moves 400 times on the surface of the workpiece to simulate the machining process.
The temperature field heat source model is characterized in that according to the shape of the cutting thickness of a single abrasive particle, the cutting thickness of the single abrasive particle gradually increases from a cutting-in area to a cutting-out area, and a triangular heat source is selected, wherein the triangular heat source is defined as formula (2):
step three: calculation of abrasive grain-workpiece interface contact pressure
And then calculating the contact pressure of an abrasive particle-workpiece interface based on a physical action model of the effective abrasive particles in the grinding arc area and the workpiece material, wherein the steps are as follows: the grinding force applied by the workpiece surface random selection unit is analyzed by stress, the pressure applied to the unit surface (namely the contact pressure between the abrasive particles and the workpiece interface) is calculated according to the following mode, and the grinding force measured by experiments is divided by the number of the abrasive particles in the grinding arc area to obtain the acting force applied to each abrasive particle, wherein the acting force is as follows:
The blade tenon tooth creep deep forming grinding residual stress prediction method based on the thermal coupling effect between the grinding temperature and the contact pressure of the abrasive particle-workpiece interface is characterized in that the acting force exerted by a single abrasive particle is divided by the acting force area A CS of the abrasive particle, and finally the pressure exerted on the unit surface is obtained, as shown in formula (4):
Where P n and P t are the normal and tangential pressures applied to the cell surface, respectively. The operating path in Ansys is Solution Define Loads structure Pressure, applied P n and P t are 2500MPa and 5400MPa, respectively. The force bearing area a CS of the abrasive particles is calculated as follows:
Acs＝πdmeanhcu (5)
wherein d mean is the diameter of the abrasive particles, and 180 μm is taken; h cu is the exposed height of the abrasive grains, and is 20 μm.
Step four: calculation of blade tenon tooth creep deep forming grinding temperature
Based on thermal analysis, firstly converting a thermal analysis unit Solid70 into a structural analysis unit Solid185, wherein an operation path in Ansys is preprocessor| ELEMENT TYPE | SWITCH ELEM TYPE, and Thermal to Struc is selected in a pop-up option box; the result of the thermal analysis is then converted into a load to be applied to the finite element model, and the operating path in Ansys is solution|definition Loads|application|structure|temperature|From THERM ANALY; and defining constraint conditions, and constraining all degrees of freedom On the bottom surface and 4 side surfaces of the workpiece so as to simulate the state of being clamped On a workbench in the workpiece machining process, wherein the upper surface of the workpiece, namely a grinding arc area, is extruded by a grinding wheel in the grinding process, so that the uppermost unit positioned On the surface of a tenon tooth is also required to be constrained, and the operation path in Ansys is solution|definition loads|application|structure|displacement|on area. And then, based on a physical action model of the effective abrasive particles in the grinding arc area and the workpiece material, applying a grinding force load generated by the contact of the abrasive particles and the workpiece, and finally simulating a machining process by using a small-step intermittent jump type moving load, namely loading the grinding force in the grinding arc area at different moments, moving to another area for loading in a next period of time, and taking the result of the previous calculation as an initial condition of the analysis.
After the grinding force loading is completed, simulation analysis is carried out on the model, and after the simulation calculation is finished, the uppermost unit (wherein the thickness of the unit is the grinding depth) of the blade tenon tooth is hidden, and as shown in fig. 5, the operation path in Ansys is select| Entities |elements. And checking simulation results to finally obtain residual stress distribution of the surface of the tenon tooth under the action of thermal coupling between the grinding temperature and the contact pressure of the abrasive particle-workpiece interface. And obtaining the blade tenon tooth surface grinding residual stress distribution. The simulation calculation of the residual stress of the thermal coupling effect between the blade tenon tooth grinding temperature and the abrasive grain-workpiece interface contact pressure is completed, as shown in fig. 6.
In order to verify the accuracy of the calculation result of the residual stress simulation method provided by the invention, a grinding test of the micro-crystal corundum grinding wheel creep deep cutting grinding nickel-based single crystal superalloy DD6 turbine blade tenon tooth is carried out. Grinding experiments are carried out by using a grinding center (BLOHM Profimat MT-408), and a microcrystalline corundum grinding wheel (phi 400 multiplied by 20mm, A80 FF22V35) is selected; measuring the grinding temperature by adopting a semi-manual thermocouple; the grinding force measurement is carried out by adopting a KISTLER 9272 type force transducer, a KISTLER 5070A multichannel charge amplifier and a data acquisition and processing system; adopting water-based cooling liquid, wherein the flow is 45L/min, and the pressure is 15bar; the diamond forming roller is adopted for grinding wheel dressing, the dressing speed ratio is q d =0.7, the dressing feed amount is f d =1 mu m/r, and each dressing amount in the experiment is 0.1mm. After the grinding experiment is finished, residual stress detection is carried out on the tooth top area of the grinding surface of the tenon tooth, the detection equipment is Proto LXRD in Canada, the selected target material is Mn_K-alpha, the light source wavelength is 0.21031400nm, the voltage of an X-ray tube is 30kV, the tube current is 30mA, the stress average error of stress powder measurement is about 6.9MPa, and the residual stress detection result is shown in figure 8. The experimental test result is consistent with the simulation result, and the simulation result is proved to be effective.
Comparative example 1
In order to verify that the simulation method can solve the problem that the residual stress distribution of the grinding surface of the tenon tooth of the nickel-based superalloy turbine blade cannot be accurately analyzed in the prior art, grinding residual stress simulation is carried out by using a conventional method as a comparison example. In the conventional method for simulating grinding residual stress by thermal-stress coupling, only the influence of grinding temperature on the residual stress is generally considered, so that the first three steps in the conventional simulation method are the same as the method for simulating the residual stress by thermal coupling between the grinding temperature and the contact pressure of the abrasive particle-workpiece interface, and only the simulation calculation step in the fourth step is described in detail, and the specific steps are as follows:
Step one: three-dimensional modeling of blade tenon tooth
Step two: blade tenon tooth model material attribute assignment
Step three: finite element grid modeling for blade tenon tooth model
Step four: conventional simulation method for calculating residual stress of grinding surface
The grinding residual stress calculation carried out by the conventional simulation method is based on a finite element grid model of the blade tenon of the nickel-based single crystal superalloy DD6, the Thermal flow and the Heat exchange amount in the actual grinding process are loaded on the surface of the blade tenon workpiece, the Thermal analysis is carried out on the Thermal flow and the Heat exchange amount in the process, the operation path in Ansys is Solution I defined Loads I Thermal Heat Flux & Convection, the size of Hear Flux is 150000W/m 2.C, the size of Convection is 6700W/m 2.C, the small-step intermittent jump type moving load is adopted to simulate the processing process based on the idea of finite element dispersion, namely, constant Heat flow density is loaded in a grinding arc area at different moments, the Heat flow is loaded in another area in the next period, the result of the previous calculation is taken as the initial condition of the analysis, and in order to simultaneously consider the calculation amount and the calculation accuracy, the discrete step adopted here is 400 steps, namely, the Heat source is moved 400 times on the surface of the workpiece to simulate the processing process.
According to the temperature field heat source model, according to the shape of cutting thickness of a single abrasive particle, the cutting thickness of the single abrasive particle gradually increases from a cutting-in area to a cutting-out area, and a triangular heat source is selected, wherein the definition formula is as follows:
Based on thermal analysis, firstly converting the thermal analysis unit Solid70 into a structural analysis unit Solid185, and selecting Thermal to Struc in a pop-up option box for an operation path of preprocessor| ELEMENT TYPE | SWITCH ELEM TYPE in Ansys; the result of the thermal analysis is then converted into a load to be applied to the finite element model, and the operating path in Ansys is solution|definition Loads|application|structure|temperature|From THERM ANALY; and defining constraint conditions, and constraining all degrees of freedom On the bottom surface and 4 side surfaces of the workpiece so as to simulate the clamped state in the workpiece machining process, wherein an operation path in Ansys is Solution definition Loads applied structure Displacement On. And carrying out thermal-stress coupling analysis on the model to obtain residual stress on the grinding surface of the tenon tooth of the formed grinding blade, which is gradually fed by the microcrystalline corundum grinding wheel, as shown in figure 7.
Therefore, if the grinding residual stress is calculated by adopting a conventional method in a simulation mode, namely, only the effect of the grinding temperature is considered in a simulation model, the residual stress value in the simulation result is very small: from the tooth tip to the tooth root of the tooth, the residual tensile stress increases and decreases, and the tensile stress reaches a maximum value, namely 12MPa, on the tooth surface of the tooth, as shown in FIG. 7, and does not conform to the actual measurement result. If the interaction between abrasive particles and a workpiece on the working surface of the grinding wheel is considered in the simulation process, residual compressive stress is formed on the tooth top, and the magnitude of the compressive stress is-150 MPa; from the tooth tip to the tooth root, the compressive stress gradually decreased and converted to a tensile stress, and then the tensile stress gradually increased and reached a maximum of 125Mpa, as shown in fig. 6, which is consistent with the experimental results. In summary, the finite element simulation model of the grinding residual stress taking the thermal coupling effect between the grinding temperature and the contact pressure of the abrasive particle-workpiece interface into consideration can calculate the creep deep forming grinding residual stress of the blade tenon tooth more accurately.
Claims (5)
1. Firstly, establishing a three-dimensional model of a turbine blade tenon tooth by using three-dimensional design software, storing an output format of a generated three-dimensional model in a solid model, and importing the output format into finite element software to establish a finite element model of the blade tenon tooth; inputting the tenon tooth material attribute of the nickel-based superalloy blade according to the requirement of finite element software, and selecting unit types and dividing grids; then, carrying out blade tenon tooth creep deep cutting forming grinding temperature finite element analysis and abrasive particle-workpiece interface contact pressure calculation; finally, based on the thermal analysis and the contact pressure calculation result, performing thermal-stress coupling simulation calculation of the grinding residual stress;
The method comprises the following specific steps:
Step one, modeling a blade tenon tooth finite element of an aeroengine: the three-dimensional modeling of the blade tenon tooth is to build a blade tenon tooth entity model by using three-dimensional design software, and import the generated model into finite element simulation software; the material attribute assignment of the blade tenon tooth model comprises the steps of inputting temperature calculation and material attribute related to stress calculation according to the requirement of finite element simulation software; the finite element grid modeling of the blade tenon tooth model comprises unit type selection and grid division;
step two, calculating the temperature of slowly feeding, deeply cutting and forming the blade tenon tooth: applying heat flow and convection heat exchange quantity to the surface of the tenon tooth model, and performing simulation calculation on the grinding temperature of the tenon tooth of the slowly-entering deeply-cutting formed grinding blade to obtain the temperature distribution of the tenon tooth in the grinding process;
Step three, calculating the contact pressure of the abrasive particle-workpiece interface: calculating the contact pressure according to the number of the abrasive particles, the size of the abrasive particles and the grinding force based on a contact pressure action model between the effective abrasive particles in the grinding arc area and the workpiece material;
In the third step, random units are selected on the surface of the workpiece when the contact pressure of the abrasive particle-workpiece interface is applied, so that interaction between the abrasive particles and the workpiece is simulated; firstly, calculating the grinding force of the surface of a random unit, dividing the grinding force measured by an experiment by the number of abrasive particles in a grinding arc area to obtain the acting force born by each abrasive particle, wherein the acting force is represented by the following formula (3):
Wherein F n and F t are respectively the normal grinding force and the tangential grinding force which are actually measured in the grinding experiment, N is the number of abrasive particles in a grinding arc area, and F n ' and F t ' are respectively the normal grinding force and the tangential grinding force which are applied to a single abrasive particle;
Since the grinding force should be applied in the form of pressure, then the force applied to the individual abrasive grains is divided by the force-bearing area a CS of the abrasive grains, and the contact pressure applied to the surface of the unit is finally obtained, as shown in formula (4):
Wherein P n and P t are the normal pressure and tangential pressure applied to the cell surface, respectively;
Step four, blade tenon tooth creep deep cutting forming grinding residual stress simulation calculation: the calculation of residual stress formed by thermal coupling action between the grinding temperature and the contact pressure of the abrasive particle-workpiece interface is based on the simulation calculation of the grinding temperature, the contact pressure between the effective abrasive particle and the workpiece material is coupled, and the residual stress of the joggled deeply-shaped grinding blade tenon tooth is calculated through finite element simulation software, so that the residual stress distribution of the grinding surface is obtained, and the calculated residual stress result is checked after the calculation is completed.
2. The blade tenon tooth creep deep forming grinding residual stress prediction method according to claim 1, characterized in that: in the second step, the temperature field heat source model is used for gradually increasing the cutting thickness of the single abrasive particles from the cutting-in area to the cutting-out area according to the cutting thickness of the single abrasive particles, and a triangular heat source is selected.
3. The blade tenon tooth creep deep forming grinding residual stress prediction method according to claim 1, characterized in that: in the first step, the material properties are density, specific heat capacity, thermal conductivity, thermal expansion coefficient, elastic modulus, poisson's ratio, yield strength and tangential modulus.
4. The blade tenon tooth creep deep forming grinding residual stress prediction method according to claim 1, characterized in that: in the first step, finite element grid modeling of a blade tenon tooth model comprises unit type selection and grid division; the unit type is selected, wherein one unit is a physical unit used in thermal calculation, and the other unit is a physical unit used in stress calculation; the grid division is to consider the requirements of calculation amount and calculation precision, reasonably control the grid division density, refine the grids of key parts and realize the reasonable distribution of the precision of the grid division of the blade tenon of the nickel-based superalloy aeroengine.
5. The blade tenon tooth creep deep forming grinding residual stress prediction method according to claim 1, wherein the method comprises the following steps: in the fourth step, after calculation is completed, when the residual stress result of the blade tenon tooth is checked, since the uppermost material of the tenon tooth is extruded by the grinding wheel and is a material removal area, the uppermost grid unit of the tenon tooth needs to be hidden, wherein the thickness of the unit is the grinding depth.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN106503350A (en) * | 2016-10-25 | 2017-03-15 | 北京航空航天大学 | A kind of spiral bevel gear long-life based on grinding and heat treatment is driven the method for designing of fatigue reliability |
| CN106503289A (en) * | 2016-09-18 | 2017-03-15 | 南京航空航天大学 | The polycrystalline CBN abrasive particles soldering that is split based on Thiessen polygon and the synergistic stress simulation method of grinding |
| CN107273630A (en) * | 2017-06-28 | 2017-10-20 | 华中科技大学 | A kind of method for calculating residual stress machined parameters by parametric inversion |
-
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN106503350A (en) * | 2016-10-25 | 2017-03-15 | 北京航空航天大学 | A kind of spiral bevel gear long-life based on grinding and heat treatment is driven the method for designing of fatigue reliability |
| CN107273630A (en) * | 2017-06-28 | 2017-10-20 | 华中科技大学 | A kind of method for calculating residual stress machined parameters by parametric inversion |
Non-Patent Citations (1)
| Title |
|---|
| 面向航空发动机的镍基合金磨削技术研究进展;丁文锋等;《机械工程学报》;第189-215页 * |
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