Static simulation high-cycle fatigue life analysis method based on spinning belt wheel

Abstract

The invention provides a spinning belt wheel static simulation-based high-cycle fatigue life analysis method, which comprises an ANSYS-based spinning belt wheel actual working condition numerical simulation modeling method, and the modeling method introduces the elements of the rotation speed, the fixed support, the pressure and the standard earth gravity of a spinning belt wheel model; in the established model, the axial load of the belt wheel is converted into pressure according to a formula, the pressure is added to serve as the constraint in the working process of the spinning belt wheel, the equivalent stress of the spinning belt wheel is obtained through ansys simulation, an S value in an S-N curve is obtained through average stress correction, an N value is obtained through the S-N curve, and then the high-cycle fatigue life of the spinning belt wheel is calculated through a miner rule formula. According to the method, the stress condition of the spinning belt wheel under the actual working condition can be more intuitively obtained, the fatigue life of the spinning belt wheel can be more accurately calculated, and reliable reference data basis can be provided for developing the spinning belt wheel with excellent fatigue service performance.

Description

Technical Field

[0001] The invention relates to the technical field of model analysis, and in particular to a high cycle fatigue life analysis method based on static simulation of a spinning pulley. Background Art

[0002] Pulleys are an important transmission part, widely used in various mechanical equipment such as aerospace, engineering machinery, agricultural machinery, automobiles, machine tools, etc. In order to overcome the shortcomings of traditional processes and realize the lightweight design of pulleys, in recent decades, countries around the world have been committed to the research of advanced pulley forming technology - spinning technology. The pulleys produced using this technology have the advantages of smooth transmission, high precision, material saving, high production efficiency, environmental protection, and long service life. Its related technical research has long attracted widespread attention and achieved considerable scientific research results. However, due to the alternating loads during the transmission power and motion process, the main failure mode of spinning pulleys is fatigue failure, and fatigue failure is relatively hidden, and often no obvious deformation will occur before the damage, which can easily lead to serious safety accidents and is difficult to prevent.

[0003] At present, fatigue tests on spun pulleys mainly involve hanging the pulleys and rotating them until microcracks appear. This fatigue test is not only time-consuming, labor-intensive and material-intensive, but also has a long measurement cycle. Therefore, some studies have used spun pulleys as research objects, and used limit stress diagrams to derive the fatigue safety operating range of plastic parts with both bending and shear deformations and the fatigue safety factor calculation formula under the composite stress state, and calculated its fatigue safety factor with the help of finite element calculation results. With the help of fatigue safety factors, we can determine whether the pulley has fatigue failure, which is of great significance for the judgment and determination of the fatigue life of the pulley. Summary of the invention

[0004] The present invention proposes a high-cycle fatigue life analysis method based on static simulation of a spinning pulley, obtains a stress-strain cloud diagram of a spinning pulley based on ANSYS static simulation, uses nCode to obtain an SN curve, uses the Goodman equation to perform average stress correction, and finally calculates the high-cycle fatigue life of a spinning pulley based on Miner's theorem. The application of this technical solution can more intuitively obtain the stress conditions of the spinning pulley under actual working conditions, and can more accurately calculate the fatigue life of the spinning pulley, which is helpful to provide a reliable reference data basis for the development of a spinning pulley with excellent fatigue service performance.

[0005] The present invention adopts the following technical solutions.

[0006] A high cycle fatigue life analysis method based on statics simulation of a spun pulley, the analysis method includes a modeling method based on ANSYS for numerical simulation of actual working conditions of a spun pulley, the modeling method introduces the elements of rotation speed, fixed support, pressure and standard earth gravity of the spun pulley model; in the constructed model, the axial load on the pulley is converted into pressure according to a formula, and the pressure is added as a constraint in the working process of the spun pulley, the equivalent stress of the spun pulley is obtained by ANSYS simulation, and then the S value in the SN curve is obtained by average stress correction, and then the N value is obtained by the SN curve, and then the high cycle fatigue life of the spun pulley is calculated by the miner's rule formula.

[0007] The method further includes obtaining the SN curve of the material based on nCode, and performing fatigue life calculation based on Miner's theorem.

[0008] The method comprises the following steps:

[0009] Step S1, establishing a geometric model of a spinning pulley;

[0010] Step S2, selecting materials and setting their physical parameters;

[0011] Step S3, defining the gravity acceleration, pressure, fixed support, rotation speed and analysis settings under the actual working conditions of the spinning pulley;

[0012] Step S4, performing mesh division and obtaining the equivalent stress cloud map of the material;

[0013] Step S5, obtaining the SN curve of the material;

[0014] Step S6, performing mean stress correction;

[0015] Step S7, performing high cycle fatigue life calculation.

[0016] Step S1 includes the following steps:

[0017] Step S1.1, use Solidworks to model the spinning pulley: the maximum diameter of the outer circle of the pulley is 192mm, the minimum diameter of the inner circle is 87mm, there are a total of 7 V-grooves and 2 spring grooves. The final spinning pulley physical model is as follows Figure 1 ;

[0018] Step S1.2: After modeling is completed, in order to facilitate subsequent mesh division and improve mesh quality, the pulley is imported into Ansys DesignModeler; a circle with a diameter of 150 mm is drawn with the center point of the pulley on the xy plane as the center;

[0019] Step S1.3, using the extrusion command to cut the pulley into two annular bodies;

[0020] Step S1.4: Use the cutting command to cut the pulley into four parts with the ZX plane as the reference plane. The final geometric model is as follows: Figure 2 .

[0021] The step S2 is specifically as follows: in EngineeringData in ANSYS, the spinning pulley material is customized as low carbon steel (SPHE), and the specific steel grade is 08AL; the physical parameters required by the model include density (Density), Young's modulus (Young's Modulus), Poisson's ratio (Poisson's Ratio), yield strength (Yield Strength), tensile strength (TensileStrength), fatigue strength (Fatigue strength), and ambient temperature (Temperature). See Table 1 for details.

[0022]

[0023] Step S3 specifically includes the following steps:

[0024] Step S3.1, add standard earth gravity and set gravity acceleration to 9806.6 mm / s 2 ;

[0025] Step S3.2, add pressure, the pressure conversion formula is:

[0026]

[0027] Where F is the shaft load of the spinning pulley under actual working conditions, 1800N, and S is the tooth groove side area, 65.8cm 2 , θ is the V-shaped tooth groove angle of 40°.

[0028] Step S3.3, add fixed support, and select the large inner ring of the spinning pulley as the fixed support surface;

[0029] Step S3.4, add the rotation speed and set it to 1500 rad / s;

[0030] Step S3.5, set the number of steps, current number of steps, initial sub-step and minimum sub-step of the corresponding analysis process of the software to 1, the step end time to 1s, and the maximum sub-step to 10.

[0031] The step S4 is specifically as follows:

[0032] Step S4.1, select the sweep method for the outer annular body of the pulley, set the swept unit size to the required value of 2mm, and select quadrilateral / triangle as the free surface mesh type.

[0033] Step S4.2, the patch conformal method is selected for the inner annular body of the pulley, and the geometric body size adjustment is added, and the unit size is adjusted to the required amount of 2 mm;

[0034] Step S4.3: After the mesh is generated, add the equivalent stress command in the solution command, click the solution command to obtain the equivalent stress cloud diagram and the maximum equivalent stress value, such as Figure 3 .

[0035] The step S5 is specifically as follows:

[0036] In nCode, the physical parameters entered include: material type (MaterialType), yield strength (YS), tensile strength (UTS), elastic modulus (E), stress range intercept (SRI1), slope of the first segment of the SN curve (b1), inflection point of the two-segment SN curve (Nc1), slope of the second segment of the SN curve (b2), standard deviation of the SN curve (SE), stress ratio (RR), and cutoff limit of the SN curve (Nfc). See Table 2 for details. After entering the data, the SN diagram of the 08AL material used is obtained, as shown in Figure 4 .

[0037]

[0038] The step S6 specifically comprises the following steps:

[0039] Step S6.1, calculate the stress amplitude S a and the mean stress S m :

[0040]

[0041] Where S max is the maximum equivalent stress value in the equivalent stress cloud diagram, S min is the minimum stress value in the equivalent stress cloud diagram;

[0042] Step S6.2: Use the Goodman equation to correct the mean stress and convert the stress ratio to S min / S max The stress amplitude is converted to the stress amplitude S when the stress ratio is -1 n :

[0043]

[0044] Where: S a Indicates the stress amplitude of the material under actual working conditions, S m represents the mean stress; S n Indicates the stress amplitude of the material when the stress ratio R = -1; S u Indicates the ultimate tensile strength of a material.

[0045] The step S7 specifically includes the following steps:

[0046] Step S7.1, set the spinning pulley speed and shaft load for multiple times, and obtain the S corresponding to each setting value through steps S1 to S6. N1 , S N2 , S N3 , S N4 , S N5 ;

[0047] Take the spinning pulley speed as 1500rad / s and the shaft load as 1800N, and perform the above 6 steps to obtain S N1 ;

[0048] Take the spinning pulley speed as 1500rad / s and the shaft load as 2500N, and perform the above 6 steps to obtain S N2 ;

[0049] Take the spinning pulley speed as 1500rad / s and the shaft load as 3200N, and perform the above 6 steps to obtain S N3 ;

[0050] Take the spinning pulley speed as 2200rad / s and the shaft load as 1800N, and perform the above 6 steps to obtain S N4 ;

[0051] Take the spinning pulley speed as 3000rad / s and the shaft load as 1800N, and perform the above 6 steps to obtain S N5 ;

[0052] Step S7.2: Based on the SN curve in step S5, N1 , S N2 , S N3 , S N4 , S N5 , respectively get N 1 , N 2 , N 3 , N 4 , N 5 ,

[0053] Step S7.3, under the above five working conditions, the number of cycles of the spinning pulley is n. 1 、n 2 、n 3 、n 4 、n 5 .

[0054] Step S7.4, use Miner's theorem to calculate fatigue life:

[0055]

[0056] N i is the spin pulley under load S i The number of cycles of fatigue life, n i is the spin pulley under load S i The number of cycles below.

[0057] The present invention proposes a high-cycle fatigue life analysis method based on static simulation of a spinning pulley, including a modeling method based on ANSYS for numerical simulation of actual working conditions of a spinning pulley, taking into account factors such as the rotation speed, fixed support, pressure, and standard earth gravity of the model, obtaining a stress-strain cloud map of the spinning pulley based on ANSYS static simulation, using nCode to obtain an SN curve, using the Goodman equation to perform average stress correction, and finally calculating the high-cycle fatigue life of the spinning pulley based on Miner's theorem. The application of this technical solution can more intuitively obtain the stress conditions of the spinning pulley under actual working conditions, and can more accurately calculate the fatigue life of the spinning pulley, which is helpful to provide a reliable reference data basis for the development of a spinning pulley with excellent fatigue service performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0059] Attached Figure 1 This is a schematic diagram of the Solidworks model of the spinning pulley;

[0060] Attached Figure 2 This is a schematic diagram of the DesignModeler model of a spinning pulley;

[0061] Attached Figure 3 It is a schematic diagram of the equivalent stress cloud diagram of the spinning pulley;

[0062] Attached Figure 4 It is a schematic diagram of the SN curve of the spinning pulley. DETAILED DESCRIPTION

[0063] As shown in the figure, a high-cycle fatigue life analysis method based on static simulation of a spun pulley is provided, the analysis method includes a modeling method based on ANSYS for numerical simulation of actual working conditions of a spun pulley, the modeling method introduces the elements of rotation speed, fixed support, pressure and standard earth gravity of the spun pulley model; in the constructed model, the axial load on the pulley is converted into pressure according to the formula, and the pressure is added as a constraint in the working process of the spun pulley, the equivalent stress of the spun pulley is obtained by ANSYS simulation, and then the S value in the SN curve is obtained by average stress correction, and then the N value is obtained by the SN curve, and then the high-cycle fatigue life of the spun pulley is calculated by the miner's law formula.

[0064] The method further includes obtaining the SN curve of the material based on nCode, and performing fatigue life calculation based on Miner's theorem.

[0065] The method comprises the following steps:

[0066] Step S1, establishing a geometric model of a spinning pulley;

[0067] Step S2, selecting materials and setting their physical parameters;

[0068] Step S3, defining the gravity acceleration, pressure, fixed support, rotation speed and analysis settings under the actual working conditions of the spinning pulley;

[0069] Step S4, performing mesh division and obtaining the equivalent stress cloud map of the material;

[0070] Step S5, obtaining the SN curve of the material;

[0071] Step S6, performing mean stress correction;

[0072] Step S7, performing high cycle fatigue life calculation.

[0073] Step S1 includes the following steps:

[0074] Step S1.1, use Solidworks to model the spinning pulley: the maximum diameter of the outer circle of the pulley is 192mm, the minimum diameter of the inner circle is 87mm, there are a total of 7 V-grooves and 2 spring grooves. The final spinning pulley physical model is as follows Figure 1 ;

[0075] Step S1.2: After modeling is completed, in order to facilitate subsequent mesh division and improve mesh quality, the pulley is imported into Ansys DesignModeler; a circle with a diameter of 150 mm is drawn with the center point of the pulley on the xy plane as the center;

[0076] Step S1.3, using the extrusion command to cut the pulley into two annular bodies;

[0077] Step S1.4: Use the cutting command to cut the pulley into four parts with the ZX plane as the reference plane. The final geometric model is as follows: Figure 2 .

[0078] The step S2 is specifically as follows: in EngineeringData in ANSYS, the spinning pulley material is customized as low carbon steel (SPHE), and the specific steel grade is 08AL; the physical parameters required by the model include density (Density), Young's modulus (Young's Modulus), Poisson's ratio (Poisson's Ratio), yield strength (Yield Strength), tensile strength (TensileStrength), fatigue strength (Fatigue strength), and ambient temperature (Temperature). See Table 1 for details.

[0079]

[0080] Step S3 specifically includes the following steps:

[0081] Step S3.1, add standard earth gravity and set gravity acceleration to 9806.6 mm / s 2 ;

[0082] Step S3.2, add pressure, the pressure conversion formula is:

[0083]

[0084] Where F is the shaft load of the spinning pulley under actual working conditions, 1800N, and S is the tooth groove side area, 65.8cm 2 , θ is the V-shaped tooth groove angle of 40°.

[0085] Step S3.3, add fixed support, and select the large inner ring of the spinning pulley as the fixed support surface;

[0086] Step S3.4, add the rotation speed and set it to 1500 rad / s;

[0087] Step S3.5, set the number of steps, current number of steps, initial sub-step and minimum sub-step of the corresponding analysis process of the software to 1, the step end time to 1s, and the maximum sub-step to 10.

[0088] The step S4 is specifically as follows:

[0089] Step S4.1, select the sweep method for the outer annular body of the pulley, set the swept unit size to the required value of 2mm, and select quadrilateral / triangle as the free surface mesh type.

[0090] Step S4.2, the patch conformal method is selected for the inner annular body of the pulley, and the geometric body size adjustment is added, and the unit size is adjusted to the required amount of 2 mm;

[0091] Step S4.3: After the mesh is generated, add the equivalent stress command in the solution command, click the solution command to obtain the equivalent stress cloud diagram and the maximum equivalent stress value, such as Figure 3 .

[0092] The step S5 is specifically as follows:

[0093] In nCode, the physical parameters entered include: material type (MaterialType), yield strength (YS), tensile strength (UTS), elastic modulus (E), stress range intercept (SRI1), slope of the first segment of the SN curve (b1), inflection point of the two-segment SN curve (Nc1), slope of the second segment of the SN curve (b2), standard deviation of the SN curve (SE), stress ratio (RR), and cutoff limit of the SN curve (Nfc). See Table 2 for details. After entering the data, the SN diagram of the 08AL material used is obtained, as shown in Figure 4 .

[0094]

[0095] The step S6 specifically comprises the following steps:

[0096] Step S6.1, calculate the stress amplitude S a and the mean stress S m :

[0097]

[0098] Where S max is the maximum equivalent stress value in the equivalent stress cloud diagram, S min is the minimum stress value in the equivalent stress cloud diagram;

[0099] Step S6.2: Use the Goodman equation to correct the mean stress and convert the stress ratio to S min / S max The stress amplitude is converted to the stress amplitude S when the stress ratio is -1 n :

[0100]

[0101] Where: S a Indicates the stress amplitude of the material under actual working conditions, S m represents the mean stress; S n Indicates the stress amplitude of the material when the stress ratio R = -1; S u Indicates the ultimate tensile strength of a material.

[0102] The step S7 specifically includes the following steps:

[0103] Step S7.1, set the spinning pulley speed and shaft load for multiple times, and obtain the S corresponding to each setting value through steps S1 to S6. N1 , S N2 , S N3 , S N4 , S N5 ;

[0104] Take the spinning pulley speed as 1500rad / s and the shaft load as 1800N, and perform the above 6 steps to obtain S N1 ;

[0105] Take the spinning pulley speed as 1500rad / s and the shaft load as 2500N, and perform the above 6 steps to obtain S N2 ;

[0106] Take the spinning pulley speed as 1500rad / s and the shaft load as 3200N, and perform the above 6 steps to obtain S N3 ;

[0107] Take the spinning pulley speed as 2200rad / s and the shaft load as 1800N, and perform the above 6 steps to obtain S N4 ;

[0108] Take the spinning pulley speed as 3000rad / s and the shaft load as 1800N, and perform the above 6 steps to obtain S N5 ;

[0109] Step S7.2: Based on the SN curve in step S5, N1 , S N2 , S N3 , S N4 , S N5 , respectively get N 1 , N 2 , N 3 , N 4 , N 5 ,

[0110] Step S7.3, under the above five working conditions, the number of cycles of the spinning pulley is n. 1 、n 2 、n 3 、n 4 、n 5 .

[0111] Step S7.4, use Miner's theorem to calculate fatigue life:

[0112]

[0113] N i is the spin pulley under load S iThe number of cycles of fatigue life, n i is the spin pulley under load S i The number of cycles below.

Claims

1. A high cycle fatigue life analysis method based on static simulation of spinning pulleys, characterized by: The analysis method includes a modeling method based on ANSYS for numerical simulation of actual working conditions of a spinning pulley, wherein the modeling method introduces the elements of rotation speed, fixed support, pressure and standard earth gravity of the spinning pulley model; In the constructed model, the axial load on the pulley is converted into pressure according to the formula, and the pressure is added as a constraint during the working process of the spun pulley. The equivalent stress of the spun pulley is obtained by ANSYS simulation, and then the S value in the SN curve is obtained by average stress correction, and then the N value is obtained from the SN curve. Finally, the high-cycle fatigue life of the spun pulley is calculated by the Miner's law formula.

2. The high cycle fatigue life analysis method based on static simulation of spinning pulley according to claim 1, characterized in that: The method further includes obtaining the SN curve of the material based on nCode, and performing fatigue life calculation based on Miner's theorem.

3. The high cycle fatigue life analysis method based on static simulation of spinning pulley according to claim 2, characterized in that: The method comprises the following steps: Step S1, establishing a geometric model of a spinning pulley; Step S2, selecting materials and setting their physical parameters; Step S3, defining the gravity acceleration, pressure, fixed support, rotation speed and analysis settings under the actual working conditions of the spinning pulley; Step S4, performing mesh division and obtaining the equivalent stress cloud map of the material; Step S5, obtaining the SN curve of the material; Step S6, performing mean stress correction; Step S7, performing high cycle fatigue life calculation.

4. The high cycle fatigue life analysis method based on static simulation of spinning pulley according to claim 3 is characterized by: Step S1 includes the following steps: Step S1.1, using Solidworks to model the spinning pulley: the model sets the maximum outer diameter of the pulley, the minimum inner diameter, the number of V-grooves, and the number of spring grooves; Step S1.2, after the modeling is completed, in order to facilitate the subsequent mesh division and improve the mesh quality, the pulley is imported into Ansys Design Modeler; a circle of the required diameter is drawn with the center point of the pulley on the xy plane as the center; Step S1.3, using the extrusion command to cut the pulley into two annular bodies; Step S1.4, use the cutting command to cut the pulley into four parts with the ZX plane as the reference plane to obtain a geometric model.

5. The high cycle fatigue life analysis method based on static simulation of spinning pulley according to claim 3, characterized in that: The step S2 specifically includes: customizing the spinning pulley material as low carbon steel in EngineeringData in ANSYS; the physical parameters required by the model include density, Young's modulus, Poisson's ratio, yield strength, tensile strength, fatigue strength, and ambient temperature.

6. The high cycle fatigue life analysis method based on static simulation of spinning pulley according to claim 3, characterized in that: Step S3 specifically The steps include: Step S3.1, add standard earth gravity and set gravity acceleration; Step S3.2, add pressure, the pressure conversion formula is: Where F is the shaft load under the actual working condition of the spinning pulley, S is the side area of ​​the tooth groove, and θ is the V-shaped tooth groove angle. Step S3.3, add fixed support, select the large inner ring of the spinning pulley as the fixed support surface; Step S3.4, adding rotation speed; Step S3.5, set the number of steps, current number of steps, initial sub-step and minimum sub-step, step end time, and maximum sub-step of the corresponding analysis process of the software.

7. The high cycle fatigue life analysis method based on static simulation of spinning pulley according to claim 3 is characterized by: The step S4 is specifically as follows: Step S4.1, select the sweep method for the outer annular body of the pulley, set the swept element size to the required value, and select quadrilateral / triangle as the free surface mesh type. Step S4.2, the patch conformal method is selected for the inner annular body of the pulley, and the geometric body size adjustment is added, and the unit size is adjusted to the required amount; Step S4.3: After the mesh is generated, add the equivalent stress command in the solution command, and click the solution command to obtain the equivalent stress cloud diagram and the maximum equivalent stress value.

8. The high cycle fatigue life analysis method based on static simulation of spinning pulley according to claim 3 is characterized by: The step S5 is specifically as follows: In nCode, you can customize the SN curve. The physical parameters you input include: material type MaterialType, yield strength YS, tensile strength UTS, elastic modulus E, stress range intercept SRI1, slope b1 of the first segment of the SN curve, inflection point Nc1 of the two-segment SN curve, slope b2 of the second segment of the SN curve, standard deviation SE of the SN curve, stress ratio RR, and cutoff limit Nfc of the SN curve. After inputting the data, you can get the SN diagram of the material used.

9. The high cycle fatigue life analysis method based on static simulation of spinning pulley according to claim 3, characterized in that: The step S6 specifically comprises the following steps: Step S6.1, calculate the stress amplitude S a and the mean stress S m : Where S max is the maximum equivalent stress value in the equivalent stress cloud diagram, S min is the minimum stress value in the equivalent stress cloud diagram; Step S6.2, use the Goodman equation to correct the average stress, and convert the stress ratio to S min / S max The stress amplitude is converted to the stress amplitude S when the stress ratio is -1 n : Where: S a Indicates the stress amplitude of the material under actual working conditions, S m represents the mean stress; S n Indicates the stress amplitude of the material when the stress ratio R = -1; S u Indicates the ultimate tensile strength of a material.

10. The high cycle fatigue life analysis method based on static simulation of spinning pulley according to claim 3, characterized in that: The step S7 specifically includes the following steps: Step S7.1, set the spinning pulley speed and shaft load for multiple times, and obtain the S corresponding to each setting value through steps S1 to S6. N1 , S N2 , S N3 , S N4 , S N5 ; Step S7.2: Based on the SN curve in step S5, N1 , S N2 , S N3 , S N4 , S N5 , and get N1, N2, N3, N4, N5 respectively, Step S7.3, under the above five working conditions, the number of cycles of the spinning pulley is taken as n1, n2, n3, n4, and n5 respectively. Step S7.4, Miner's theorem is used to calculate the fatigue life: N i is the spin pulley under load S i The number of cycles of fatigue life, n i is the spin pulley under load S i The number of cycles below.

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