A load-energy double-constraint-based cushion structure reverse design method

Abstract

The present application relates to the technical field of buffer structure design, and particularly relates to a buffer structure reverse design method based on load-energy double constraint, which mainly solves the problems of low design efficiency, heavy weight and large space occupation of the existing buffer structure design method. The buffer structure reverse design method based on load-energy double constraint comprises the following steps: step one, determining design input parameters; step two, preliminarily determining load constraint; step three, determining energy constraint; step four, determining the design height of the buffer structure; step five, further determining load constraint; and step six, buffer structure size parameter iterative design. According to the specific impact environment and protection requirements, the method can accurately and efficiently deduce the size parameters such as the height and wall thickness of the buffer structure, and avoid overdesign while ensuring protection safety.

Description

Technical Field

[0001] This invention relates to the field of buffer structure design technology, specifically a reverse design method for buffer structures based on load-energy dual constraints. Background Technology

[0002] In engineering applications, many precision devices or structures (hereinafter referred to as "the protected objects") are subjected to impact loads during use. For example, in missile systems, a buffer structure needs to be set between the impact block and the protected objects to prevent them from being damaged by impact.

[0003] Existing buffer structure designs often employ trial-and-error methods or experience-based approximations, lacking systematic theoretical guidance. Particularly for buffer structures with stable plateau phases, the quantitative design relationship between design parameters and impact pulse characteristics (waveform, amplitude, pulse width) and the tolerance of the protected object remains unclear. This leads to iterative and inefficient design processes. Furthermore, to mitigate design risks, overly conservative designs are often adopted in engineering, resulting in heavier buffer structures and larger space requirements. Therefore, a universal design method is urgently needed that can accurately derive key parameters of buffer structures from performance objectives, based on the characteristics of the impactor and the protected object. Summary of the Invention

[0004] In order to solve the problems of low design efficiency and heavy weight and large space occupation of existing buffer structure design methods, this invention provides a reverse design method for buffer structures based on load-energy dual constraints.

[0005] This invention is achieved using the following technical solution:

[0006] A reverse design method for buffer structures based on load-energy dual constraints includes the following steps:

[0007] Step 1: Determine the design input parameters

[0008] Obtain the impact input conditions of the impact block, the protection requirements of the protected object, and the compaction strain of the buffer structure. The impact input conditions for the impact block include the impact acceleration waveform and the peak impact acceleration. Impact pulse width and impact block mass The protection requirements of the protected object include the quality of the protected object. The maximum permissible impact acceleration of the protected object ;

[0009] Step 2: Preliminary determination of load constraints

[0010] Calculate the maximum load that the buffer structure can be subjected to. Its expression is ;

[0011] Step 3: Determine the energy constraint

[0012] ① Based on the impact acceleration waveform and peak impact acceleration Impact pulse width Calculate the impact velocity of the impact block ;

[0013] ② Based on the law of conservation of momentum, calculate the common velocity of the impact block, the buffer structure, and the protected object after buffering. Its expression ;

[0014] ③ Calculate the minimum energy that the buffer structure needs to absorb. Its expression is ,in, The initial kinetic energy of the impact block and , The total kinetic energy after buffering by the impact block, the buffer structure, and the protected object. ;

[0015] Step 4: Determine the design height of the buffer structure

[0016] ① Based on the load constraints initially determined in step two, the energy constraints determined in step three, and the compaction strain of the buffer structure obtained in step one. The minimum height of the buffer structure required to satisfy the load-energy dual constraints is solved in reverse. Its expression is: ;

[0017] ② Determine the design height of the buffer structure This ensures that the design of the buffer structure meets the requirements. ;

[0018] Step 5: Further determine load constraints

[0019] ① Design height of the buffer structure determined in step four Calculate the effective travel of the buffer structure. Its expression is ;

[0020] ② Effective travel based on buffer structure To meet energy constraints, the minimum load allowed to be applied to the buffer structure is calculated. ;

[0021] ③ Based on the load constraints initially determined in step two, further determine the allowable load on the buffer structure. The following relationship must be satisfied: ;

[0022] Step Six: Iterative Design of Buffer Structure Dimensions

[0023] Select the structure type of the buffer structure, based on the design height of the buffer structure determined in step five. Given fixed dimensional parameters, and using the remaining unoptimized dimensional parameters of the buffer structure as design variables, the allowable load on the buffer structure is calculated iteratively. And the energy that the buffer structure can absorb. until satisfied and At this point, the size parameters of the corresponding buffer structure are the final size parameters of the buffer structure.

[0024] Furthermore, the buffer structure can be a composite multi-cell thin-walled buffer structure, a composite material sandwich structure, or a metal honeycomb structure.

[0025] The beneficial effects of this invention are as follows: The reverse design method for buffer structures described in this invention transforms the traditional trial-and-error cycle of "design-simulation-testing-redesign" into a theory-driven load-energy dual-constraint reverse design approach; this method can accurately and efficiently derive the dimensional parameters such as the height and wall thickness of the buffer structure according to specific impact environments and protection requirements, avoiding over-design while ensuring protection safety, and achieving lightweighting and performance optimization of the buffer structure; this method is universal and applicable to various buffer structure designs, significantly shortening the design cycle of impact protection devices in engineering applications. Attached Figure Description

[0026] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0028] Figure 1 This is a flowchart of the reverse design method for the buffer structure described in this invention;

[0029] Figure 2 This is a schematic diagram of the acceleration-time curve of the impact block described in an embodiment of the present invention;

[0030] Figure 3 This is a schematic diagram of the composite multicellular thin-walled buffer structure described in the embodiments of the present invention;

[0031] Figure 4 A schematic diagram of the finite element verification results for the maximum impact acceleration of the protected object.

[0032] In the figure: 1-multicellular thin-walled component, 11-outer ring, 12-inner ring, 13-rib plate, 2-aluminum foam-polyurethane composite material; - The outer diameter of the inner ring of a multicellular thin-walled component -Design height of the buffer structure, -Outer diameter of the outer ring of a multicellular thin-walled component - Wall thickness of multicellular thin-walled components -Outer ring diameter of each cell - The radial length of each cell. Detailed Implementation

[0033] To better understand the above-mentioned objectives, features, and advantages of the present invention, the solutions of the present invention will be further described below. It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other.

[0034] Many specific details are set forth in the following description in order to provide a full understanding of the invention, but the invention may also be practiced in other ways different from those described herein; obviously, the embodiments in the specification are only some embodiments of the invention, and not all embodiments.

[0035] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0036] like Figure 1 As shown, a reverse design method for a buffer structure based on load-energy dual constraints includes the following steps:

[0037] Step 1: Determine the design input parameters

[0038] Obtain the impact input conditions of the impact block, the protection requirements of the protected object, and the compaction strain of the buffer structure. The impact input conditions for the impact block include the impact acceleration waveform and the peak impact acceleration. Impact pulse width and impact block mass The protection requirements of the protected object include the quality of the protected object. The maximum permissible impact acceleration of the protected object ;

[0039] Step 2: Preliminary determination of load constraints

[0040] Calculate the maximum load that the buffer structure can be subjected to. Its expression is ;

[0041] Step 3: Determine the energy constraint

[0042] ① Based on the impact acceleration waveform and peak impact acceleration Impact pulse width Calculate the impact velocity of the impact block ;

[0043] ② Based on the law of conservation of momentum, calculate the common velocity of the impact block, the buffer structure, and the protected object after buffering. Its expression ;

[0044] ③ Calculate the minimum energy that the buffer structure needs to absorb. Its expression is ,in, The initial kinetic energy of the impact block and , The total kinetic energy after buffering by the impact block, the buffer structure, and the protected object. ;

[0045] Step 4: Determine the design height of the buffer structure

[0046] ① Based on the load constraints initially determined in step two, the energy constraints determined in step three, and the compaction strain of the buffer structure obtained in step one. The minimum height of the buffer structure required to satisfy the load-energy dual constraints is solved in reverse. Its expression is: ;

[0047] ② Determine the design height of the buffer structure This ensures that the design of the buffer structure meets the requirements. ;

[0048] Step 5: Further determine load constraints

[0049] ① Design height of the buffer structure determined in step four Calculate the effective travel of the buffer structure. Its expression is ;

[0050] ② Effective travel based on buffer structure To meet energy constraints, the minimum load allowed to be applied to the buffer structure is calculated. ;

[0051] ③ Based on the load constraints initially determined in step two, further determine the allowable load on the buffer structure. The following relationship must be satisfied: ;

[0052] Step Six: Iterative Design of Buffer Structure Dimensions

[0053] Select the structure type of the buffer structure, based on the design height of the buffer structure determined in step five. Given fixed dimensional parameters, and using the remaining unoptimized dimensional parameters of the buffer structure as design variables, the allowable load on the buffer structure is calculated iteratively. And the energy that the buffer structure can absorb. until satisfied and At this point, the size parameters of the corresponding buffer structure are the final size parameters of the buffer structure.

[0054] In practice, the buffer structure should be an energy dissipation structure with a stable load plateau stage, such as a composite multi-cell thin-walled buffer structure, a composite material sandwich structure, or a metal honeycomb structure.

[0055] The reverse design method of the buffer structure described above will be explained in detail below through specific embodiments.

[0056] A reverse design method for buffer structures based on load-energy dual constraints includes the following steps:

[0057] Step 1: Determine the design input parameters

[0058] Obtain the impact input conditions of the impact block, the protection requirements of the protected object, and the compaction strain of the buffer structure. The impact input conditions for the impact block include a half-sine impact acceleration waveform and a peak impact acceleration. Impact pulse width and impact block mass ,like Figure 2 The diagram shows the acceleration-time curve of the impact block; the protection requirements for the protected object include the mass of the protected object. The maximum permissible impact acceleration of the protected object , For gravitational acceleration; for the compaction strain of the buffer structure ;

[0059] Step 2: Preliminary determination of load constraints

[0060] Calculate the maximum load that the buffer structure can be subjected to. This means that the load on the buffer structure during the impact process must be controlled below 98kN to ensure the safety of the protected object.

[0061] Step 3: Determine the energy constraint

[0062] ① Based on the half-sine impact acceleration waveform and peak impact acceleration Impact pulse width Calculate the impact velocity of the impact block = ,in, The impact acceleration is a half-sine waveform and ,in The duration of the impact;

[0063] ② Based on the law of conservation of momentum, calculate the common velocity of the impact block, the buffer structure, and the protected object after buffering. Its expression ;

[0064] ③ Calculate the minimum energy that the buffer structure needs to absorb. Its expression is ,in, The initial kinetic energy of the impact block and , The total kinetic energy after buffering by the impact block, the buffer structure, and the protected object. Therefore, we obtain ;

[0065] Step 4: Determine the design height of the buffer structure

[0066] ① Based on the load constraints initially determined in step two, the energy constraints determined in step three, and the compaction strain of the buffer structure obtained in step one. The minimum height of the buffer structure required to satisfy the load-energy dual constraints is solved in reverse. ;

[0067] ② To allow for margin, determine the design height of the buffer structure. ,satisfy ;

[0068] Step 5: Further determine load constraints

[0069] ① Design height of the buffer structure determined in step four Calculate the effective travel of the buffer structure. = ;

[0070] ② Effective travel based on buffer structure To meet energy constraints, the minimum load allowed to be applied to the buffer structure is calculated. ;

[0071] ③ Based on the load constraints initially determined in step two, further determine the allowable load on the buffer structure. The following relationship must be satisfied: ;

[0072] Step Six: Iterative Design of Buffer Structure Dimensions

[0073] The selected buffer structure type is a composite multicellular thin-walled buffer structure, such as... Figure 3 As shown, the buffer structure is a lightweight, high-energy-absorbing type of buffer structure. It is an impact energy dissipation structure formed by coupling a ring-shaped multi-cell thin-walled component 1 composed of multiple cells and a foam aluminum-polyurethane composite material 2 filled in multiple cells. The multi-cell thin-walled component 1 includes an outer ring 11, an inner ring 12 and a rib 13.

[0074] Due to space constraints, the outer diameter of the outer ring 11 of the multicellular thin-walled component 1 is selected. The outer diameter of the inner ring 12 of the multicellular thin-walled component 1 Yield strength of multicellular thin-walled member 1 Plateau stress of multiple cell-filled aluminum-polyurethane foam composite material 2 Calculate the outer ring diameter of each cell. The inner ring diameter of each cell ,in The wall thickness of the multicellular thin-walled component 1 and the dimensional parameters to be iteratively optimized are the buffer structure.

[0075] The wall thickness of multi-cell thin-walled component 1 in the composite multi-cell thin-walled buffer structure Generally, a thickness of 0.6-1.5 mm is used. The wall thickness of the multicellular thin-walled component 1 is calculated according to the following steps. Iterative calculations are performed in ascending order:

[0076] a. Calculate the radial length of each cell. The total cross-sectional area of ​​the aluminum-polyurethane foam composite material 2 filled in multiple cells The multi-cell-filled aluminum-polyurethane foam composite 2 allows for the application of loads. The energy that can be absorbed by the aluminum-polyurethane foam composite material 2 filled with multiple cells. ;

[0077] b. The fully plastic bending moment per unit width is The total length of the plastic hinge in the cross section is The bending coefficient of a complete folded unit The membrane energy coefficient of a complete folded unit The plastic energy dissipation of a complete folded unit is ,in, For the folded half-wavelength of the buffer structure, a fully folded unit allows for the applied load. To allow the load to be applied to a complete folding unit Minimize, i.e. The folded half-wavelength of the buffer structure can be obtained. The number of folds in the effective stroke of the multicellular thin-walled component 1 The energy that the multicellular thin-walled component 1 can absorb within its effective stroke. ;

[0078] c. Iterative calculation of the load allowed to be applied by the buffer structure Iterative calculation of the energy that the buffer structure can absorb ;

[0079] d. The load that the buffer structure can be subjected to, as determined by iterative calculation. and the energy that the buffer structure can absorb. Each satisfies and When the condition is met, the iteration ends, and the wall thickness of the corresponding multicellular thin-walled component is determined. These are the size parameters after iterative optimization of the buffer structure. At this point, the design of all size parameters in the buffer structure is complete, as shown in Table 1 below, which contains the iterative calculation results.

[0080] Table 1 Iterative Calculation Results Data Table

[0081]

[0082] Note: The load constraint criteria in Table 1 are as follows: The energy constraint criterion is .

[0083] As shown in Table 1, the final designed buffer structure is a composite multi-cell thin-walled buffer structure, and the wall thickness of multi-cell thin-walled component 1 is... The outer diameter of the outer ring 11 of the multicellular thin-walled component 1 The outer diameter of the inner ring 12 of the multicellular thin-walled component 1 Yield strength of multicellular thin-walled member 1 Plateau stress of multiple cell-filled aluminum-polyurethane foam composite material 2 Compaction strain of the buffer structure The design height of the buffer structure The design scheme theoretically satisfies both load constraints and energy constraints, and maximizes lightweighting.

[0084] Finally, a finite element analysis model was established using the dimensional parameters of the final designed buffer structure as described above. The maximum impact acceleration of the protected object was then verified using this finite element model. The verification results are as follows: Figure 4 As shown, the maximum impact acceleration of the protected object is ,Right now The impact acceleration did not exceed the maximum allowable acceleration of the protected object. This demonstrates that the reverse design method for the buffer structure described in this invention is feasible.

[0085] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the present invention. Although detailed descriptions have been provided with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments, and all should be covered by the protection scope of the claims.

Claims

1. A reverse design method for buffer structures based on load-energy dual constraints, characterized in that, Includes the following steps: Step 1: Determine the design input parameters Obtain the impact input conditions of the impact block, the protection requirements of the protected object, and the compaction strain of the buffer structure. The impact input conditions for the impact block include the impact acceleration waveform and the peak impact acceleration. Impact pulse width and impact block mass The protection requirements of the protected object include the quality of the protected object. The maximum permissible impact acceleration of the protected object ; Step 2: Preliminary determination of load constraints Calculate the maximum load that the buffer structure can be subjected to. Its expression is ; Step 3: Determine the energy constraint ① Based on the impact acceleration waveform and peak impact acceleration Impact pulse width Calculate the impact velocity of the impact block ; ② Based on the law of conservation of momentum, calculate the common velocity of the impact block, the buffer structure, and the protected object after buffering. Its expression ; ③ Calculate the minimum energy that the buffer structure needs to absorb. Its expression is ,in, The initial kinetic energy of the impact block and , The total kinetic energy after buffering by the impact block, the buffer structure, and the protected object. ; Step 4: Determine the design height of the buffer structure ① Based on the load constraints initially determined in step two, the energy constraints determined in step three, and the compaction strain of the buffer structure obtained in step one. The minimum height of the buffer structure required to satisfy the load-energy dual constraints is solved in reverse. Its expression is: ; ② Determine the design height of the buffer structure This ensures that the design of the buffer structure meets the requirements. ; Step 5: Further determine load constraints ① Design height of the buffer structure determined in step four Calculate the effective travel of the buffer structure. Its expression is ; ② Effective travel based on buffer structure To meet energy constraints, the minimum load allowed to be applied to the buffer structure is calculated. ; ③ Based on the load constraints initially determined in step two, further determine the allowable load on the buffer structure. The following relationship must be satisfied: ; Step Six: Iterative Design of Buffer Structure Dimensions Select the structure type of the buffer structure, based on the design height of the buffer structure determined in step five. Given fixed dimensional parameters, and using the remaining unoptimized dimensional parameters of the buffer structure as design variables, the allowable load on the buffer structure is calculated iteratively. And the energy that the buffer structure can absorb. until satisfied and At this point, the size parameters of the corresponding buffer structure are the final size parameters of the buffer structure.

2. The reverse design method for a buffer structure based on load-energy dual constraints according to claim 1, characterized in that, The buffer structure can be a composite multi-cell thin-walled buffer structure, a composite material sandwich structure, or a metal honeycomb structure.

Images