Design method of polyurea coating for protecting vulnerable metal components of engineering equipment
Patent Information
- Application Number
- CN202611126015.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-07-28
- Publication Date
- 2026-10-16
AI Technical Summary
[0005]本发明所要解决的技术问题是：现有技术缺少相应的设计方式导致的喷涂厚度与爆炸当量不匹配的问题
[0059] This invention provides a complete and systematic polyurea coating protection design method that organically links the characteristics of the threat source, the resistance of the component itself, and the performance of the coating material. It makes the mechanical properties and spraying thickness of the elastic coating material match the impact load on the component, realizes scientific and quantitative design, and finally forms a finished component through high-pressure spraying construction, forming a closed loop from design to implementation, ensuring the effective implementation of the design scheme.
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Figure CN122926772A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a design method for protecting vulnerable metal components of engineering equipment with polyurea coating, belonging to the field of metal component protection technology. Background Technology
[0002] Armor protection is a crucial element in ensuring the functional operation of weaponry and equipment. With the continuous evolution of warfare, the likelihood of non-armored vehicles such as military transport vehicles and fuel supply vehicles being exposed to combat has significantly increased. Local conflicts and the threat of terrorist attacks mean that the powerful shockwaves and shrapnel from small arms projectiles and improvised explosive devices (IEDs) can cause severe damage to vehicles, especially their vulnerable components such as metal skin shells, fuel tanks, guide tubes, and connectors, thus affecting the equipment's ability to perform its intended mission. Therefore, protective designs targeting non-armored vehicles are receiving increasing attention.
[0003] The mission requirements of unarmored vehicles necessitate excellent mobility; therefore, increasing the thickness of the metal structure is not advisable. Adding lightweight aluminum foam or fibers can improve the structure's impact resistance, but the complex construction process and high costs limit its application. Designing lightweight, high-strength protective materials that can be efficiently and conveniently implemented for protection is a crucial trend in the field of structural protection, and is of great significance for maintaining the combat effectiveness of vehicles and other equipment.
[0004] Spraying polyurea elastomers allows for the rapid application of polymer materials to the surface of structural components, quickly curing to form a highly adhesive coating that significantly enhances the structure's impact resistance. Scientific experiments have shown that applying a polyurea coating of a specific thickness can double or even more the impact resistance of a structure; however, the unique mechanical properties and diverse formulations of polyurea mean that its effects are not entirely blast-resistant, and it may even, to some extent, exacerbate component damage. Therefore, correctly selecting polyurea coating materials and scientifically designing the coating thickness are crucial for reliable protection. Summary of the Invention
[0005] The technical problem to be solved by the present invention is the mismatch between the coating thickness and the explosive equivalent caused by the lack of corresponding design methods in the prior art.
[0006] To solve the above-mentioned technical problems, the present invention is implemented using the following technical solution.
[0007] On one hand, the present invention provides a design method for protecting vulnerable metal components of engineering equipment with polyurea coating, comprising:
[0008] Obtain the characteristic parameters of the threat source, as well as the effective distance of the threat source relative to the component to be protected;
[0009] Based on the characteristic parameters of the threat source and the action distance, the initial value of the impact load on the surface of the component to be protected is calculated. The initial value of the impact load includes the specific impulse and specific kinetic energy of the threat source acting on the surface of the component to be protected.
[0010] Obtain the structural geometric parameters of the component to be protected;
[0011] Based on the structural geometric parameters and the preset protection level standards, the damage threshold value corresponding to the component to be protected under each damage level is determined.
[0012] The initial value of the impact load is compared with the critical value of the damage to determine the dominant failure mode of the component to be protected.
[0013] Based on the dominant failure mode, the material mechanical properties and coating location of the polyurea coating are selected;
[0014] Based on the selected material mechanical properties and coating location of the polyurea coating, the thickness of the polyurea coating is calculated to form a protective design scheme;
[0015] Apply a polyurea coating to the surface of the component to be protected according to the protective design scheme.
[0016] By organically linking the characteristics of the threat source, the inherent resistance of the component, and the performance of the coating material, the mechanical properties and spraying thickness of the elastic coating material are matched with the impact load on the component, thus achieving scientific and quantitative design.
[0017] The threat sources include explosive charges and / or fragments;
[0018] When the threat source is an explosive charge, the threat source characteristic parameters include: charge type and the equivalent TNT mass of the explosive charge; when the threat source is fragments, the threat source characteristic parameters include fragment mass.
[0019] The steps for calculating the specific impulse are as follows:
[0020] Based on the equivalent TNT mass of the explosive charge and the effective distance, the proportional distance is calculated using the following formula:
[0021] ,
[0022] in, For proportional distance, For the effective range, Equivalent TNT mass;
[0023] The shock wave overpressure of the explosive charge is calculated using the following formula:
[0024] ,
[0025] in, For shock wave overpressure;
[0026] The specific impulse is calculated using the following formula:
[0027] ,
[0028] in, For specific impulse, For coefficients;
[0029] The steps for calculating the specific kinetic energy are as follows:
[0030] The initial velocity of the fragment is calculated using the following formula:
[0031] ,
[0032] in, Initial velocity of the fragment, These are empirical parameters. Let Gurney's constant be 1. This is the filling factor;
[0033] The remaining velocity of the fragment after it reaches the stated effective distance is calculated using the following formula:
[0034] ,
[0035] in, For any distance The fragment velocity at the location, It is a power function of the natural constant e. The attenuation coefficient is... air density, The windward side;
[0036] The specific kinetic energy is calculated using the following formula:
[0037] ,
[0038] in, For specific kinetic energy, For fragment quality, This represents the remaining velocity of the fragment when it reaches the surface of the component.
[0039] The structural geometric parameters include the wall thickness of the component to be protected, and for curved components, the radius of curvature.
[0040] Taking wall thickness and radius of curvature into account makes the determination of damage threshold more accurate.
[0041] The critical damage value is obtained by comprehensive calculation based on the structural geometric parameters and by consulting relevant standards and specifications.
[0042] The damage threshold includes the specific impulse criterion. Sum of specific kinetic energy criteria .
[0043] The dominant destruction modes include:
[0044] when and At that time, it is a non-destructive mode, in which, Specific impulse, As a criterion for specific impulse, For specific kinetic energy, As a criterion for specific kinetic energy;
[0045] when and At that time, the destruction mode was dominated solely by the blast shock wave;
[0046] when and At that time, the damage mode was dominated solely by fragments;
[0047] when and At that time, the destruction mode was dominated by the combined effect of the explosion shock wave and fragmentation.
[0048] By combining the two sets of criteria in pairs, the complex composite impact conditions are clearly divided into four typical failure modes.
[0049] The mechanical properties of the material include tensile strength and tear strength;
[0050] Depending on the dominant failure mode, the tensile strength and tear strength correspond to different preset threshold ranges.
[0051] The coating location includes: coating on the blast-facing surface of the component to be protected, coating on the blast-back surface of the component to be protected, or coating on both the blast-facing and blast-back surfaces of the component to be protected.
[0052] The material's mechanical properties and the coating location are determined based on the dominant failure mode and the preset correspondence between the optimal coating location and the dominant failure mode.
[0053] The step of calculating the polyurea coating thickness includes:
[0054] The thickness is obtained by substituting the structural geometric parameters, the initial value of the impact load, and the selected material mechanical property index into a preset thickness calculation equation.
[0055] When the component to be protected is a flat plate structure and the dominant failure mode is destruction solely caused by an explosive shock wave, the thickness calculation equation is the ratio equation of the polyurea coating thickness to the wall thickness of the component to be protected.
[0056] When the dominant failure mode is fragment-dominated failure alone, the thickness calculation equation is a penetration thickness equation based on the remaining velocity of the fragment.
[0057] Different thickness calculation models are used for different failure modes. When the explosion shock wave is dominant, the model is mainly based on impulse matching, while when the fragmentation is dominant, the model is mainly based on the penetration residual velocity matching. The thickness calculation is quantitatively correlated with the intensity of the threat source, the geometry of the component, and the material properties, so that the coating thickness is accurately matched with the explosion equivalent, saving engineering costs.
[0058] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:
[0059] This invention provides a complete and systematic polyurea coating protection design method that organically links the characteristics of the threat source, the resistance of the component itself, and the performance of the coating material. It makes the mechanical properties and spraying thickness of the elastic coating material match the impact load on the component, realizes scientific and quantitative design, and finally forms a finished component through high-pressure spraying construction, forming a closed loop from design to implementation, ensuring the effective implementation of the design scheme. Attached Figure Description
[0060] Figure 1 This is a flowchart illustrating the design method for protecting vulnerable metal components of polyurea-coated engineering equipment as shown in Embodiment 1 of the present invention.
[0061] Figure 2 This is a comparison of the anti-explosion effect of polyurea-coated metal components shown in Embodiment 1 of the present invention;
[0062] Figure 3 This is a comparison of the anti-fragmentation impact effect of the polyurea coated component shown in Embodiment 1 of the present invention;
[0063] Figure 4 This is a comparison of the combined effect of the polyurea-coated component in Embodiment 1 of the present invention in resisting explosive shock waves and fragments. Detailed Implementation
[0064] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solution of the present invention, rather than limitations thereof. In the absence of conflict, the embodiments of the present invention and the technical features in the embodiments can be combined with each other.
[0065] The term "and / or" simply describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. Additionally, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.
[0066] Example 1
[0067] This embodiment describes a design method for protecting vulnerable metal components of engineering equipment with polyurea coating, including:
[0068] Obtain the characteristic parameters of the threat source, as well as the effective distance of the threat source relative to the component to be protected;
[0069] Based on the characteristic parameters of the threat source and the action distance, the initial value of the impact load on the surface of the component to be protected is calculated. The initial value of the impact load includes the specific impulse and specific kinetic energy of the threat source acting on the surface of the component to be protected.
[0070] Obtain the structural geometric parameters of the component to be protected;
[0071] Based on the structural geometric parameters and the preset protection level standards, the damage threshold value corresponding to the component to be protected under each damage level is determined.
[0072] The initial value of the impact load is compared with the critical value of the damage to determine the dominant failure mode of the component to be protected.
[0073] Based on the dominant failure mode, the material mechanical properties and coating location of the polyurea coating are selected;
[0074] Based on the selected material mechanical properties and coating location of the polyurea coating, the thickness of the polyurea coating is calculated to form a protective design scheme;
[0075] Apply a polyurea coating to the surface of the component to be protected according to the protective design scheme.
[0076] The threat sources include explosive charges and / or fragments;
[0077] When the threat source is an explosive charge, the threat source characteristic parameters include: charge type and the equivalent TNT mass of the explosive charge; when the threat source is fragments, the threat source characteristic parameters include fragment mass.
[0078] The steps for calculating the specific impulse are as follows:
[0079] Based on the equivalent TNT mass of the explosive charge and the effective distance, the proportional distance is calculated using the following formula:
[0080] ,
[0081] in, For proportional distance, The effective range, Equivalent TNT mass;
[0082] The shock wave overpressure of the explosive charge is calculated using the following formula:
[0083] ,
[0084] in, For shock wave overpressure;
[0085] The specific impulse is calculated using the following formula:
[0086] ,
[0087] in, Specific impulse, For coefficients;
[0088] The steps for calculating the specific kinetic energy are as follows:
[0089] The initial velocity of the fragment is calculated using the following formula:
[0090] ,
[0091] in, Initial velocity of the fragment, These are empirical parameters. Let Gurney's constant be 1. This is the filling factor;
[0092] Specifically, natural fragments Pre-formed fragments ;
[0093] The remaining velocity of the fragment after it reaches the stated effective distance is calculated using the following formula:
[0094] ,
[0095] in, For any distance The fragment velocity at the location, It is a power function of the natural constant e. The attenuation coefficient is... air density, The windward side;
[0096] The specific kinetic energy is calculated using the following formula:
[0097] ,
[0098] in, For specific kinetic energy, For fragment quality, This represents the remaining velocity of the fragment when it reaches the surface of the component.
[0099] The structural geometric parameters include the wall thickness of the component to be protected, and for curved components, the radius of curvature.
[0100] The damage threshold is obtained by comprehensive calculation based on the structural geometric parameters and by consulting relevant standards and specifications.
[0101] The damage threshold includes the specific impulse criterion. Sum of specific kinetic energy criteria .
[0102] The dominant destruction modes include:
[0103] when and At that time, it is a non-destructive mode, in which, Specific impulse, As a criterion for specific impulse, For specific kinetic energy, As a criterion for specific kinetic energy;
[0104] when and At that time, the destruction mode was dominated solely by the blast shock wave;
[0105] when and At that time, the damage mode was dominated solely by fragments;
[0106] when and At that time, the destruction mode was dominated by the combined effect of the explosion shock wave and fragmentation.
[0107] The mechanical properties of the material include tensile strength and tear strength;
[0108] Depending on the dominant failure mode, the tensile strength and tear strength correspond to different preset threshold ranges.
[0109] The coating location includes: coating on the blast-facing surface of the component to be protected, coating on the blast-back surface of the component to be protected, or coating on both the blast-facing and blast-back surfaces of the component to be protected.
[0110] The material's mechanical properties and the coating location are determined based on the dominant failure mode and the preset correspondence between the optimal coating location and the dominant failure mode.
[0111] Specifically, the correspondence between the optimal coating location and the dominant failure mode is as follows:
[0112] For individual explosive impact loads, polyurea coating can be applied to both the blast-facing and blast-avoiding surfaces of flat structures. The tensile strength of polyurea is [not specified]. With tear strength satisfy: ≥35MPa; ≥115N / mm; Due to the stringent requirements of the inner surface coating process for pipe fittings, polyurea should be coated on the explosion-proof surface of the pipe fitting structure. Polyurea tensile strength With tear strength satisfy: ≥16MPa; ≥64N / mm;
[0113] For single fragment impact loads, the hardness of polyurea materials needs to be constrained. When polyurea is coated on the blast-facing surface of a structure, the material properties required include: tensile strength. ≥25MPa, tear strength ≥90MPa, hardness ≥70HD; when polyurea is coated on the back surface of a structure, its material properties requirements are: tensile strength ≥35MPa, tear strength ≥115MPa, hardness ≥55HD;
[0114] For applications involving combined fragmentation and shock wave loads, and for the design and manufacturing of new engineering equipment, as well as for the protective upgrades of existing engineering equipment with unrestricted coating processes, double-sided polyurea spraying is recommended. The material must possess both hardness and tensile strength. Generally, the following requirements apply: tensile strength... ≥25MPa, tear strength ≥90MPa, hardness ≥70HD.
[0115] The step of calculating the polyurea coating thickness includes:
[0116] The thickness is obtained by substituting the structural geometric parameters, the initial value of the impact load, and the selected material mechanical property index into a preset thickness calculation equation;
[0117] When the component to be protected is a flat plate structure and the dominant failure mode is destruction solely caused by an explosive shock wave, the thickness calculation equation is the ratio equation of the polyurea coating thickness to the wall thickness of the component to be protected.
[0118] When the dominant failure mode is fragment-dominated failure alone, the thickness calculation equation is a penetration thickness equation based on the remaining velocity of the fragment.
[0119] In this embodiment, such as Figure 1 As shown, the design method for protecting vulnerable metal components of engineering equipment with polyurea coating includes the following steps:
[0120] Step 1: Determine the type and form of the explosion and shock threat source, whether it contains explosives, casings, or other source materials that can generate shock waves and fragments, and estimate the equivalent TNT mass and fragment mass of the explosives in the hazard source.
[0121] Step 2: Determine the distance between the center of the explosion threat source and the surface of the component affected;
[0122] Step 3: Calculate the propagation characteristics of the shock wave in the medium, calculate the initial velocity of the projectile / fragment and its flight attenuation characteristics, and calculate the specific impulse and specific kinetic energy acting on the surface of the component;
[0123] Step 4: Measure the thickness, radius of curvature R, and other characteristic dimensions of the component to be protected;
[0124] Step 5: For the application scenario of the component, consult the protection level standards to determine the damage criteria corresponding to different damage levels, namely the impulse criterion and the specific kinetic energy criterion.
[0125] Step 6: Compare the specific impulse and fragment specific kinetic energy of the shock wave generated by the threat source with the damage criteria to determine the form and characteristics of the final impact load;
[0126] Specifically, based on the ratio of the two criteria, the damage to the component can be divided into the following four categories:
[0127] Operating Condition 1: and In this case, neither the shock wave nor the fragments can cause structural damage;
[0128] Operating Condition 2: and In this case, only the destructive effect of the shock wave can cause structural damage, and the effect of fragments can be ignored in the protective design;
[0129] Operating Condition 3: and In this case, only the impact of fragments can cause structural damage, and the effect of shock waves can be ignored in the protective design;
[0130] Operating Condition 4: and In this situation, both shock waves and fragments can cause structural damage, and both must be considered in the protective design.
[0131] Step 7: Based on the different types of impact loads determined in Step 6, design the range of basic mechanical parameters of polyurea material and determine the optimal coating position scheme for polyurea coating.
[0132] Step 8: Based on the preferred polyurea material and coating location, design the polyurea coating thickness to form the final protective design scheme;
[0133] Specifically, for plate structures subjected to a single explosive impact load, at the explosion proportional distance Under certain conditions, polyurea coating thickness With the thickness of the matrix material Compared to satisfying relations: For tubular structures subjected to isolated explosive impact loads, at the explosion proportional distance... Under certain conditions, polyurea coating thickness With the thickness of the steel substrate material Compared to satisfying relations: At the explosion ratio distance Under certain conditions, polyurea coating thickness With the thickness of the aluminum substrate material Compared to satisfying relations: ;
[0134] Specifically, for single fragment impact loads, when coating the blast-facing surface, the polyurea coating thickness... With remaining speed The following relationship must be satisfied: ,in , , , When coating the back side, the polyurea coating thickness With remaining speed Satisfy the following relations: ,in , , , ;
[0135] Specifically, for the combined load of fragmentation and shock wave, the explosion proportional distance Under these conditions, the thickness of the polyurea coating on the front side With the thickness of the matrix material The relationship between ratios: Explosion ratio distance Under certain conditions, the thickness of the polyurea coating on the back side With the thickness of the matrix material The relationship between ratios: .
[0136] Step 9: Apply a polyurea coating to the surface of the component to be protected according to the protection design plan to complete the protection design for the vulnerable metal components.
[0137] In its specific implementation, this invention first addresses the lack of design and calculation methods for elastic coatings used in metal components. It involves conducting hundreds of explosion tests to investigate the explosion and projectile impact resistance of different substrate configurations coated with polyurea coatings of varying thicknesses, as well as the explosion and projectile impact resistance performance of different types of polyurea elastic coatings. A series of comparative tests were conducted, and through repeated comparisons, it was found that only elastic coating materials meeting the physical and mechanical properties specified in step 7 possess superior explosion and projectile impact resistance performance. The explosion resistance effect of polyurea-coated metal components is compared to... Figure 2 The effect of polyurea-coated components on resisting fragment impact is, for example... Figure 3 The combined effect of polyurea-coated components in resisting blast shock waves and fragmentation is significant, for example... Figure 4 .
[0138] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.
[0139] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.
[0140] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.
[0141] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.
[0142] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.
Claims
1. A design method for protecting vulnerable metal components of engineering equipment with polyurea coating, characterized in that, include: Obtain the characteristic parameters of the threat source, as well as the effective distance of the threat source relative to the component to be protected; Based on the characteristic parameters of the threat source and the action distance, the initial value of the impact load on the surface of the component to be protected is calculated. The initial value of the impact load includes the specific impulse and specific kinetic energy of the threat source acting on the surface of the component to be protected. Obtain the structural geometric parameters of the component to be protected; Based on the structural geometric parameters and the preset protection level standards, the damage threshold value corresponding to the component to be protected under each damage level is determined. The initial value of the impact load is compared with the critical value of the damage to determine the dominant failure mode of the component to be protected. Based on the dominant failure mode, the material mechanical properties and coating location of the polyurea coating are selected; Based on the selected material mechanical properties and coating location of the polyurea coating, the thickness of the polyurea coating is calculated to form a protective design scheme; Apply a polyurea coating to the surface of the component to be protected according to the protective design scheme.
2. The design method for protecting vulnerable metal components of engineering equipment with polyurea coating according to claim 1, characterized in that, The threat sources include explosive charges and / or fragments; When the threat source is an explosive charge, the threat source characteristic parameters include: charge type and the equivalent TNT mass of the explosive charge; when the threat source is fragments, the threat source characteristic parameters include fragment mass.
3. The design method for protecting vulnerable metal components of engineering equipment with polyurea coating according to claim 2, characterized in that, The steps for calculating the specific impulse are as follows: Based on the equivalent TNT mass of the explosive charge and the effective distance, the proportional distance is calculated using the following formula: ， in, For proportional distance, The effective range, Equivalent TNT mass; The shock wave overpressure of the explosive charge is calculated using the following formula: ， in, For shock wave overpressure; The specific impulse is calculated using the following formula: ， in, For specific impulse, For coefficients; The steps for calculating the specific kinetic energy are as follows: The initial velocity of the fragment is calculated using the following formula: ， in, Initial velocity of the fragment, These are empirical parameters. Let Gurney's constant be 1. This is the filling factor; The remaining velocity of the fragment after it reaches the stated effective distance is calculated using the following formula: ， in, For any distance The fragment velocity at the location, It is a power function of the natural constant e. The attenuation coefficient is... air density, The windward side; The specific kinetic energy is calculated using the following formula: ， in, For specific kinetic energy, For fragment quality, This represents the remaining velocity of the fragment when it reaches the surface of the component.
4. The design method for protecting vulnerable metal components of engineering equipment with polyurea coating according to claim 1, characterized in that, The structural geometric parameters include the wall thickness of the component to be protected, and for curved components, the radius of curvature.
5. The design method for protecting vulnerable metal components of engineering equipment with polyurea coating according to claim 1, characterized in that, The damage threshold is obtained by comprehensive calculation based on the structural geometric parameters and by consulting relevant standards and specifications. The damage threshold includes the specific impulse criterion. Sum of specific kinetic energy criteria .
6. The design method for protecting vulnerable metal components of engineering equipment with polyurea coating according to claim 1, characterized in that, The dominant destruction modes include: when and At that time, it is a non-destructive mode, in which, For specific impulse, As a criterion for specific impulse, For specific kinetic energy, As a criterion for specific kinetic energy; when and At that time, the destruction mode was dominated solely by the blast shock wave; when and At that time, the damage mode was dominated solely by fragments; when and At that time, the destruction mode was dominated by the combined effect of the explosion shock wave and fragmentation.
7. The design method for protecting vulnerable metal components of engineering equipment with polyurea coating according to claim 1, characterized in that, The mechanical properties of the material include tensile strength and tear strength; Depending on the dominant failure mode, the tensile strength and tear strength correspond to different preset threshold ranges.
8. The design method for protecting vulnerable metal components of engineering equipment with polyurea coating according to claim 1, characterized in that, The coating location includes: coating on the blast-facing surface of the component to be protected, coating on the blast-back surface of the component to be protected, or coating on both the blast-facing and blast-back surfaces of the component to be protected.
9. The design method for protecting vulnerable metal components of engineering equipment with polyurea coating according to claim 1, characterized in that, The material's mechanical properties and the coating location are determined based on the dominant failure mode and the preset correspondence between the optimal coating location and the dominant failure mode.
10. The design method for protecting vulnerable metal components of engineering equipment with polyurea coating according to claim 1, characterized in that, The step of calculating the polyurea coating thickness includes: The thickness is obtained by substituting the structural geometric parameters, the initial value of the impact load, and the selected material mechanical property index into a preset thickness calculation equation. When the component to be protected is a flat plate structure and the dominant failure mode is destruction solely caused by an explosive shock wave, the thickness calculation equation is the ratio equation of the polyurea coating thickness to the wall thickness of the component to be protected. When the dominant failure mode is fragment-dominated failure alone, the thickness calculation equation is a penetration thickness equation based on the remaining velocity of the fragment.