Virtual impact experiment method for paint coating of suspension launching device

Abstract

The invention relates to a suspension launching device coating experiment technology, in particular to a suspension launching device paint coating virtual impact experiment method. The measurement range of the experiment table is narrow, the error of the test result is large, and the manufacturing period of the paint coating is long. According to the method, a transient dynamics theory and finite element simulation are adopted to obtain a relationship between the pit depth x and the initial velocity V of the punch, and fitting is carried out to obtain an equation between the pit depth x and the initial velocity V of the punch; building a suspended launching device paint coating impact experiment physical platform to obtain the pit depth x of the paint coating when the drop hammer falls from different heights H, and fitting to obtain an equation of the pit depth x relative to the drop hammer height H; according to an analytic expression of the punch initial velocity v relative to the drop hammer height H, calculating punch initial velocities under different height conditions to obtain pit depths and residual stresses under different height conditions; and evaluating the strength of the paint film according to the criterion. The confidence coefficient of the impact strength of the paint coating of the suspension launching device is improved, the experimental period is shortened, and the experimental efficiency is improved.

Description

Technical Field

[0001] The invention relates to a coating experimental technology for a suspended launch device, and in particular to a virtual impact experimental method for a paint coating of a suspended launch device. Background Art

[0002] As an important material for the suspension launcher, the coating can enhance the structural strength, improve the wear resistance and corrosion resistance of the structure, and thus improve the safety and reliability of the carrier aircraft. However, during the service process, the coating may be coupled with a variety of complex and harsh environments, thus affecting the safety of the carrier aircraft, among which the impact environment has attracted much attention.

[0003] At present, the impact strength of paint coatings is mainly evaluated by physical experiments. The article "Analysis on the Drying of Paint Coatings" (Mao Zhe, Yin Zhongqiu, Hu Jianfeng, published in "Modern Paints and Coatings" 2023 Issue 9) combined with GB / T 8264-2008 "Coating Technical Terms" pointed out through analysis that factors such as the mixing ratio of paint, the thickness of the paint coating, the temperature and the quality of the paint will affect the performance of the paint coating. It can be seen that the impact strength of the paint coating is easily affected by environmental factors such as temperature and humidity, thereby reducing the performance of the coating. According to the current laboratory experimental results, the measurement range of the test bench is narrow, and it can only measure the depth of the paint coating pit within a certain height range, and the lower the drop height, the greater the error of the test result. The sample is easily impacted and jumps during the test, which causes errors in the results. In addition, the production cycle of the paint coating is long. Summary of the invention

[0004] The purpose of the present invention is to provide a virtual impact test method for the paint coating of a suspension launching device, so as to solve the problem that the impact test results of the paint coating of the suspension launching device are affected by various environmental coupling factors such as temperature and humidity, so as to improve the confidence of the impact strength of the paint coating of the suspension launching device, shorten the experimental cycle and improve the experimental efficiency.

[0005] The virtual impact test method scheme of the paint coating of the suspension launch device to achieve the purpose of the present invention is as follows:

[0006] S1. Construct a virtual impact test platform for paint coating of suspended launch device;

[0007] S2, using transient dynamics theory and finite element simulation to obtain the relationship between the pit depth x and the punch initial velocity V;

[0008] S3, based on the Origin data processing platform, the equation of the pit depth x related to the punch initial velocity V is obtained by fitting;

[0009] S4. Build a physical platform for the paint coating impact test of the suspended launch device, and obtain the pit depth x of the paint coating when the drop hammer falls from different heights H through a limited number of physical experiments;

[0010] S5. Based on the Origin data processing platform, the equation of the pit depth x and the drop weight height H is obtained by fitting;

[0011] S6. The simultaneous equations give the analytical expression of the punch initial velocity v with respect to the drop hammer height H;

[0012] S7, calculating the initial velocity of the punch under different height conditions, and using it as the load condition for the virtual impact test of the paint coating of the suspension launch device, and obtaining the pit depth and residual stress under different height conditions;

[0013] S8. Evaluate the strength of the paint film based on the criteria.

[0014] Advantageously, S1 includes establishing a virtual impact test digital model and a Lagrangian finite element model.

[0015] Advantageously, constructing a Lagrangian finite element numerical model mainly includes constructing a material constitutive model, constructing a link relationship, meshing and unit types, and boundary conditions and load conditions.

[0016] Advantageously, S2 comprises the following steps:

[0017] S2.1. Calculate the maximum velocity and minimum velocity of the falling hammer at the maximum range Hmax and the minimum range Hmin respectively by the free fall formula, obtain the curve of the change of the punch velocity with time by collision simulation, and determine the initial velocity range of the punch;

[0018] S2.2. Calculate the equivalent stress range and deformation range based on von Mises, that is, the residual stress range and pit depth range of the paint coating.

[0019] Advantageously, in S2.1, a three-dimensional model and a numerical model of the drop hammer impact punch need to be constructed, and the numerical model includes constructing a constitutive model of the drop hammer and punch material, constructing a mesh model, constructing a link relationship, and setting load conditions and boundary conditions.

[0020] Advantageously, the equation for the pit depth x obtained by fitting in S3 with respect to the punch initial velocity V is:

[0021]

[0022] Advantageously, the equation for the pit depth x obtained by fitting in S5 with respect to the drop weight height H is:

[0023]

[0024] Advantageously, the analytical formula of the punch initial velocity v with respect to the drop hammer height H is:

[0025]

[0026] Advantageously, 50 mm ≤ H ≤ 800 mm.

[0027] Advantageously, S8 uses "GB / T1732-2020 Paint Coating Impact Test Method" as the criterion.

[0028] Beneficial effects: Through the virtual impact experiment of the suspended launch device, the impact strength of the coating can avoid being easily affected by the environmental coupling effects such as temperature and humidity, thereby improving the accuracy of the experimental results; avoiding the production of paint coatings can significantly improve the experimental cycle and improve the experimental efficiency; it can avoid the problem of limited measurement range of the existing test bench, and then obtain the mechanical behavior under any working conditions; it can avoid the problem of low accuracy of experimental results caused by factors such as system errors and measurement errors during actual experiments, and can avoid actual experiments, thereby reducing the experimental costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is the overall flow chart of the virtual experiment on the impact strength of the paint coating of the suspension launcher;

[0030] Figure 2 It is the structural schematic diagram of the impact test platform;

[0031] Figure 3 Schematic diagram of the drop weight and punch in the impact strength test platform. DETAILED DESCRIPTION

[0032] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0033] The present invention uses tinplate as a substrate and polyurethane paint as a coating to describe in detail a virtual impact test method for a suspension launcher coating, wherein the size of the tinplate is 150mm×50mm×0.28mm, and the size of the coating is 150mm×50mm×0.02mm.

[0034] See also Figure 1 , including the following steps:

[0035] S1. Construct a virtual impact test platform for the paint coating of a suspended launch device.

[0036] It mainly includes the establishment of a digital model of virtual impact experiment and a Lagrangian finite element model.

[0037] See also Figure 2 The impact test platform includes a heavy hammer 1, a punch 2, a die 3 and a base 4, and a substrate coated with a paint coating is placed in the die 3.

[0038] The digital model of the virtual impact experiment consists of a punch, a base, a substrate and a paint coating. The paint coating is applied on the substrate, the punch is located above the substrate, and the substrate is located above the base.

[0039] The construction of Lagrangian finite element numerical model mainly includes the construction of material constitutive model, link relationship construction, mesh division and unit type, as well as boundary conditions and load conditions.

[0040] S2. The relationship between the pit depth x and the punch initial velocity V is obtained by using transient dynamics theory and finite element simulation.

[0041] The main steps include:

[0042] S2.1: Calculate the maximum and minimum speeds of the falling hammer at the maximum range Hmax and minimum range Hmin respectively by using the free fall formula, and construct the three-dimensional model and numerical model of the falling hammer impact punch, see Figure 3 The numerical model includes building the material constitutive model of the drop hammer and the punch, building the mesh model, building the link relationship, setting the load conditions and boundary conditions. The maximum speed and minimum speed of the drop hammer are set in the simulation platform, and the change curve of the punch speed over time is obtained through collision simulation. The maximum initial speed and minimum initial speed of the punch are obtained according to this change curve, and the initial speed range of the punch is determined.

[0043] The materials of the drop weight and hammer head are Q235 steel, and the Johnson-Cook model is used. The grids are unstructured grids Solid186 and Solid187. There is frictionless contact between the punch and the drop weight. The boundary conditions are to release the Z-direction constraint of the punch, and zero displacement constraints in other directions. The loads are set to the maximum and minimum initial velocity of the punch, respectively. The curve of the change of the punch velocity over time is obtained through post-processing.

[0044] S2.2: According to the initial velocity range of the punch, the equivalent stress range and deformation range are calculated based on von Mises, that is, the residual stress range and pit depth range of the paint coating.

[0045] S3. Based on the Origin data processing platform, the equation of the pit depth x related to the punch initial velocity V is:

[0046]

[0047] Step 4: Build a physical platform for the paint coating impact experiment of the suspension launch device, and obtain the pit depth x of the paint coating when the drop hammer falls from different heights H through a limited number of physical experiments. It mainly includes the following steps:

[0048] Step 4.1: Make a paint coating on the substrate;

[0049] Step 4.2: Place the substrate on the experimental table, adjust the ruler, and set different drop weight heights;

[0050] Step 4.3: Press the button to make the weight fall freely;

[0051] Step 4.4: Measure the pit depth using a vernier caliper.

[0052] Step 5: Based on the Origin data processing platform, the equation of the pit depth x with respect to the drop hammer height H is obtained as follows:

[0053]

[0054] Step 6: The analytical expression of the punch initial velocity v with respect to the drop height H is obtained by combining the equations:

[0055]

[0056] Step 7. The initial velocity of the punch under different height conditions is obtained through the analytical expression of the initial velocity v of the punch with respect to the drop hammer height H, and this is used as the load condition for the virtual impact test of the paint coating of the suspended launch device. The pit depth and residual stress under different height conditions are obtained through the virtual impact test.

[0057] Step 8. Evaluate the strength of the paint coating according to the criteria of GB / T1732-2020 Paint Coating Impact Test Method.

[0058] As analyzed above, the present invention solves the problem that the impact test results of the paint coating of the suspended launching device are affected by various environmental coupling factors such as temperature and humidity, improves the confidence level of the impact strength of the paint coating of the suspended launching device, shortens the experimental cycle, improves the efficiency of the experiment, and reduces the experimental cost.

[0059] It will be easily understood by those skilled in the art that the above description is only a preferred example of the present invention and does not limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A virtual impact test method for paint coating of a suspended launch device, characterized in that: The method comprises the following steps: S1. Construct a virtual impact test platform for paint coating of suspended launch device; S2, using transient dynamics theory and finite element simulation to obtain the relationship between the pit depth x and the punch initial velocity V; S3, based on the Origin data processing platform, the equation of the pit depth x related to the punch initial velocity V is obtained by fitting; S4. Build a physical platform for the paint coating impact test of the suspended launch device, and obtain the pit depth x of the paint coating when the drop hammer falls from different heights H through a limited number of physical experiments; S5. Based on the Origin data processing platform, the equation of the pit depth x and the drop weight height H is obtained by fitting; S6. The simultaneous equations give the analytical expression of the punch initial velocity v with respect to the drop hammer height H; S7, calculating the initial velocity of the punch under different height conditions, and using it as the load condition for the virtual impact test of the paint coating of the suspension launch device, and obtaining the pit depth and residual stress under different height conditions; S8. Evaluate the strength of the paint film based on the criteria.

2. The virtual impact test method for paint coating of a suspended launch device according to claim 1, characterized in that: S1 includes the establishment of a digital model of the virtual impact experiment and a Lagrangian finite element model.

3. The virtual impact test method for paint coating of a suspended launch device according to claim 2, characterized in that: The construction of Lagrangian finite element numerical model mainly includes the construction of material constitutive model, link relationship construction, mesh division and unit type, as well as boundary conditions and load conditions.

4. The virtual impact test method for paint coating of a suspended launch device according to claim 1, characterized in that: S2 includes the following steps: S2.

1. Calculate the maximum velocity and minimum velocity of the falling hammer at the maximum range Hmax and the minimum range Hmin respectively by the free fall formula, obtain the curve of the change of the punch velocity with time by collision simulation, and determine the initial velocity range of the punch; S2.

2. Calculate the equivalent stress range and deformation range based on von Mises, that is, the residual stress range and pit depth range of the paint coating.

5. The virtual impact test method for paint coating of a suspended launch device according to claim 4, characterized in that: In S2.1, a three-dimensional model and a numerical model of the drop hammer impact punch need to be constructed. The numerical model includes constructing the constitutive model of the drop hammer and punch material, constructing the mesh model, constructing the link relationship, and setting the load conditions and boundary conditions.

6. The virtual impact test method for paint coating of a suspended launch device according to claim 1, characterized in that: The equation of the pit depth x obtained by fitting in S3 with respect to the initial velocity V of the punch is:

7. The virtual impact test method for paint coating of a suspended launch device according to claim 6, characterized in that: The equation of the pit depth x obtained by fitting in S5 with respect to the drop weight height H is:

8. The virtual impact test method for paint coating of a suspended launch device according to claim 7, characterized in that: The analytical formula of the punch initial velocity v with respect to the drop hammer height H is:

9. The virtual impact test method for paint coating of a suspended launch device according to claim 8, characterized in that: 50mm≤H≤800mm.

10. The virtual impact test method for paint coating of a suspended launch device according to claim 1, characterized in that: S8 uses "GB / T1732-2020 Paint Coating Impact Test Method" as the basis for judgment.

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