A device for testing the compressive strength of a foamed aluminum crash beam

Abstract

The application discloses a kind of for foamed aluminium crash beam compression strength testing device, it is related to foamed aluminium mechanical property testing technical field, wherein the for foamed aluminium crash beam compression strength testing device includes pressurizing mechanism, support component, mounting assembly and pressure test module, support component and pressurizing mechanism are spaced apart along horizontal direction, and the side of support component towards pressurizing mechanism is provided with pressure test interval;Mounting assembly is enclosed and forms multiple pressure test subintervals;Pressure test module is used to respectively generate and independently output each pressure value corresponding to each pressure test subinterval according to independent pressure signal.The application can realize the independent pressure measurement of the multiple point partition of foamed aluminium sample, and provide more comprehensive and more accurate testing means for the compression resistance performance evaluation of foamed aluminium crash beam.

Description

Technical Field

[0001] This invention relates to the field of mechanical property testing technology for aluminum foam, and in particular to a device for testing the compressive strength of aluminum foam anti-collision beams. Background Technology

[0002] Aluminum foam is a porous metal material composed of a metallic aluminum matrix and a large number of interconnected or closed pores. Due to its lightweight, high specific stiffness, excellent energy absorption capacity and good buffering and shock absorption performance, it is widely used in anti-collision beam structures in rail transportation, automobile manufacturing, aerospace and other fields.

[0003] In the production and quality control of aluminum foam crash beams, compressive strength is one of the key indicators for evaluating its mechanical properties. Currently, the compressive strength test of aluminum foam materials typically uses a general-purpose universal testing machine to perform an overall compression test on the sample. The total pressure value of the entire sample under pressure is obtained through a single pressure sensor, and the average compressive strength is calculated based on this value.

[0004] However, due to the random and heterogeneous distribution of the pore structure within aluminum foam, significant differences may exist in porosity, pore size, and pore wall thickness in different local areas. Under overall pressure, the actual stress state of different local areas of the aluminum foam sample is extremely uneven—some areas may yield and deform first due to higher porosity, while other areas remain in the elastic stage. Existing single-sensor overall pressure measurement methods can only obtain a total pressure value, which reflects the average stress on the entire sample but cannot reflect the stress differences in different local areas. This results in an incomplete characterization of the overall compressive strength of aluminum foam and makes it difficult to identify local defects within the material. Furthermore, existing testing devices often use general-purpose clamping structures for sample clamping. For brittle and porous materials like aluminum foam, improper clamping can easily damage the sample edges, affecting the accuracy of the test. Summary of the Invention

[0005] The main objective of this invention is to propose a device for testing the compressive strength of aluminum foam anti-collision beams. This device aims to solve the technical problem that the single-sensor overall pressure measurement in existing aluminum foam compressive strength testing cannot reflect the local stress differences of the material. It enables multi-point independent pressure measurement of aluminum foam samples to comprehensively evaluate their compressive strength distribution.

[0006] To achieve the above objectives, the present invention provides a device for testing the compressive strength of foamed aluminum crash beams, comprising: Pressurization mechanism; A support assembly is provided, which is horizontally spaced from the pressurizing mechanism, and a pressure test zone is provided on the side of the support assembly facing the pressurizing mechanism; The mounting assembly includes multiple upper mounting columns and multiple lower mounting columns. The upper mounting columns are spaced apart along the upper edge of the pressure test interval, and the lower mounting columns are spaced apart along the lower edge of the pressure test interval. The number of upper mounting columns and lower mounting columns is the same and they are arranged in a one-to-one correspondence. A pressure test sub-interval is formed between two adjacent upper mounting columns and two corresponding lower mounting columns. Multiple pressure test sub-intervals are formed between the multiple upper mounting columns and the multiple lower mounting columns. The diameters of the multiple upper mounting columns and the multiple lower mounting columns decrease from the support assembly toward the pressurizing mechanism. The pressure testing module includes a signal receiving unit, a control unit, and multiple pressure testing units. The number of pressure testing units corresponds to the number of pressure testing sub-sections. The aluminum foam is detachably inserted and covers at least one corresponding pressure testing sub-section via at least two upper mounting posts and at least two corresponding lower mounting posts. Each pressure testing unit is embedded in a mounting groove on the side surface of the support assembly facing the pressurizing mechanism and is located at the geometric center of its corresponding pressure testing sub-section. A wire-passing hole is provided at the bottom of the mounting groove, penetrating the support assembly and extending to its back. Elastic adhesive is filled between the sidewall of the mounting groove and the outer wall of the pressure testing unit. A limiting plate is provided at the opening of the mounting groove, and an clearance hole is provided in the middle of the limiting plate. The diameter of the clearance hole is smaller than that of the pressure testing sub-section. The outer diameter of the test unit is larger than the diameter of the pressure-sensing surface of the pressure test unit. The pressure-sensing surface of the pressure test unit is flush with or 0.1 mm to 0.5 mm higher than the surface of the support assembly. The ratio of the area of ​​the pressure-sensing surface of the pressure test unit to the area of ​​the corresponding pressure test sub-interval is 1:3 to 1:5. The signal receiving unit is disposed on the support assembly and has multiple input terminals. The output terminals of the multiple pressure test units are respectively connected to the multiple input terminals of the signal receiving unit. The signal receiving unit is used to receive the independent pressure signals generated by each pressure test unit. The control unit is disposed on the support assembly and is electrically connected to the signal receiving unit. The control unit is used to generate pressure values ​​corresponding to each pressure test sub-interval based on the received independent pressure signals and to output each pressure value independently.

[0007] In one embodiment, the pressurizing mechanism includes a driving member, a pressurizing component, a base plate, and a guide component. The driving member and the support component are spaced apart. The pressurizing component extends horizontally and is disposed between the driving member and the support component. The pressurizing component is positioned corresponding to the pressure test range. The output end of the driving member is connected to the pressurizing component. The pressurizing component is connected to the guide component. The guide component is slidably engaged with the base plate.

[0008] In one embodiment, the pressurizing assembly includes a mounting base, a screw, a pressure rod, and two sleeves. The mounting base is disposed near the support assembly. The screw extends horizontally and has a first threaded segment and a second threaded segment formed thereon, with the first threaded segment and the second threaded segment having the same direction of rotation. One end of the screw is connected to the output end of the drive member, and the other end of the screw is rotatably mounted on the mounting base. The two sleeves are sleeved around the screw and threadedly connected to the first threaded segment and the second threaded segment, respectively. The pressure rod is mounted on the top of the two sleeves. The drive member is used to drive the screw to rotate, causing the two sleeves to move along the axial direction of the screw towards or away from the support assembly, so that the pressure rod compresses the aluminum foam into the pressure test zone or releases the aluminum foam into the pressure test zone.

[0009] In one embodiment, the pressure rod has a mounting hole on one side facing the pressure test zone, and the pressure assembly further includes a pressure head that extends horizontally. The two ends of the pressure head along its extension direction form a pressure end and a connection end, respectively. The connection end is threaded to the mounting hole, and the pressure end has an arc-shaped structure or a spherical structure that arches towards the pressure test zone.

[0010] In one embodiment, the guiding assembly includes two guide blocks, a guide groove is provided on the top of the base plate, both guide blocks extend vertically, the two guide blocks are spaced apart along the extension direction of the screw, the bottom ends of the two guide blocks extend into the guide groove and slide in cooperation with the guide groove, and the top ends of the two guide blocks are respectively connected to the two sleeves.

[0011] In one embodiment, the support assembly includes a support plate and a back support. The support plate extends vertically and has a pressure test area corresponding to the position of the pressurizing mechanism. The back support is installed on the side of the support plate away from the pressurizing mechanism and is inclined away from the support plate in a direction away from the pressurizing mechanism.

[0012] The technical solution of this invention divides the pressure test zone into multiple independent pressure test sub-zones using an installation component, and sets up a corresponding pressure test unit in each sub-zone. Combined with a signal receiving unit and a control unit, it enables independent acquisition and separate output of pressure signals from each sub-zone. This allows for accurate acquisition of compressive strength data for various local areas of the aluminum foam sample. The installation columns, with their decreasing diameter, provide guidance for the insertion of the aluminum foam sample, preventing edge breakage or damage due to excessive clamping force or squeezing of sharp edges. Through the placement and positioning of the installation groove, the bonding and fixing with elastic adhesive, and the mechanical limiting of the limiting plate, along with the location of the pressure test unit in the geometric center of the sub-zone and the area ratio of the pressure-sensing surface to the sub-zone, the invention ensures accurate installation of each pressure test unit, long-term stable measurement benchmarks, and no interference between signals from adjacent sub-zones. This invention effectively solves the technical problem that existing technologies cannot reflect the local stress differences caused by the non-homogeneous distribution of internal pores in aluminum foam due to the overall pressure measurement of a single sensor. It provides a more comprehensive and accurate testing method for evaluating the compressive strength of aluminum foam anti-collision beams, which helps to identify internal defects in materials and optimize the preparation process. It has important practical significance for the quality control of aluminum foam products. Attached Figure Description

[0013] 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, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of an embodiment of the device for testing the compressive strength of aluminum foam anti-collision beams provided by the present invention. Figure 2 This is an exploded structural diagram of an embodiment of the pressurization mechanism involved in the present invention; Figure 3 This is a schematic diagram of a structure of an embodiment of the support component involved in the present invention; Figure 4 This is a schematic diagram of an embodiment of the mounting component involved in the present invention; Figure 5 This is a schematic diagram of an embodiment of the pressure testing module involved in the present invention.

[0015] Explanation of icon numbers: 10. Pressurization mechanism; 20. Support assembly; 30. Mounting assembly; 31. Upper mounting column; 32. Lower mounting column; 40. Pressure test module; 41. Signal receiving unit; 42. Control unit; 43. Multiple pressure test units; 11. Drive component; 12. Pressurization assembly; 13. Base plate; 14. Guide assembly; 121. Mounting base; 122. Screw; 123. Pressurization rod; 124. Sleeve; 125. Pressurization head; 1221. First threaded section; 1222. Second threaded section; 101. Mounting hole; 102. Guide groove; 141. Guide block; 21. Support plate; 22. Back support; 201. Pressure test zone; 202. Pressure test sub-zone; 100. Aluminum foam.

[0016] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0018] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0019] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0020] Due to the random and heterogeneous distribution of the internal pore structure of aluminum foam, significant differences may exist in porosity, pore size, and pore wall thickness in different local areas. Under overall pressure, the actual stress state of different local areas of the aluminum foam sample is extremely uneven—some areas may yield and deform first due to higher porosity, while other areas remain in the elastic stage. Existing single-sensor overall pressure measurement methods can only obtain a total pressure value, which reflects the average stress of the entire sample but cannot reflect the stress differences in different local areas. This results in an incomplete characterization of the overall compressive strength of aluminum foam and makes it difficult to identify local defects within the material. Furthermore, existing testing devices often use general-purpose clamping structures for sample clamping. For brittle and porous materials like aluminum foam, improper clamping can easily damage the sample edges, affecting the accuracy of the test.

[0021] To address this technical problem, this invention proposes a device for testing the compressive strength of aluminum foam anti-collision beams.

[0022] Please see Figure 1 , Figure 3 , Figure 4 and Figure 5 In one embodiment of the present invention, the device for testing the compressive strength of aluminum foam anti-collision beams includes a pressurizing mechanism 10, a support component 20, an installation component 30, and a pressure testing module 40. The support component 20 and the pressurizing mechanism 10 are arranged horizontally at intervals, and a pressure testing zone 201 is provided on the side of the support component 20 facing the pressurizing mechanism 10. The installation component 30 is installed around the periphery of the pressure testing zone 201 and is used to detachably cover the aluminum foam 100 sample within the pressure testing zone 201. The pressure testing module 40 is installed in the pressure testing zone 201, and is positioned between the aluminum foam 100 sample and the support component 20 when the aluminum foam 100 sample is installed, generating pressure information when the pressurizing mechanism 10 compresses the aluminum foam 100 sample.

[0023] The pressurizing mechanism 10 provides the driving force to compress the aluminum foam 100 sample, and can be implemented by various means such as hydraulic drive, pneumatic drive, or electric motor drive. The support component 20 serves as the load-bearing base during the test process, and is used to withstand the extrusion force transmitted from the pressurizing mechanism 10. The pressure test zone 201 is a specific area of ​​the support component 20 facing the pressurizing mechanism 10, which corresponds to the test area of ​​the aluminum foam 100 sample.

[0024] The mounting assembly 30 includes multiple upper mounting posts 31 and multiple lower mounting posts 32. The upper mounting posts 31 are spaced apart along the upper edge of the pressure test interval 201, and the lower mounting posts 32 are spaced apart along the lower edge of the pressure test interval 201. The number of upper mounting posts 31 and lower mounting posts 32 is the same, and they are arranged in a one-to-one correspondence. A pressure test sub-interval 202 is formed between two adjacent upper mounting posts 31 and their corresponding two lower mounting posts 32, and multiple pressure test sub-intervals 202 are formed between the multiple upper mounting posts 31 and the multiple lower mounting posts 32. That is, each pair of upper mounting posts 31 and lower mounting posts 32, as well as another adjacent pair of upper mounting posts 31 and lower mounting posts 32, together form a roughly rectangular pressure test sub-interval 202 area. Both the upper mounting posts 31 and lower mounting posts 32 are fixedly mounted on the surface of the support assembly 20 facing the pressurizing mechanism 10, for example, by means of threaded connection, welding, or integral molding.

[0025] The pressure testing module 40 includes a signal receiving unit 41, a control unit 42, and multiple pressure testing units 43. The number of pressure testing units corresponds to the number of pressure testing sub-sections 202, with one pressure testing unit corresponding to each sub-section 202. The pressure testing units can be components capable of converting pressure signals into electrical signals, such as pressure sensors, strain gauge force sensors, or piezoelectric force sensors. Each pressure testing unit is embedded in the surface of the support assembly 20 facing the pressurizing mechanism 10 and is located within its corresponding pressure testing sub-section 202. The aluminum foam 100 sample is detachably inserted and covers at least one corresponding pressure testing sub-section 202 via at least two upper mounting posts 31 and at least two corresponding lower mounting posts 32. The signal receiving unit 41 is disposed on the support assembly 20 and has multiple input terminals. The output terminals of the multiple pressure testing units 43 correspond one-to-one with the multiple input terminals of the signal receiving unit 41 and are electrically connected via wires. The signal receiving unit 41 receives independent pressure signals generated by each pressure testing unit. These independent pressure signals are analog voltage or analog current signals. The control unit 42 is mounted on the support assembly 20 and is electrically connected to the signal receiving unit 41. The control unit 42 includes a multi-channel analog-to-digital converter module and a microprocessor. The microprocessor independently calculates the corresponding pressure value through each channel and outputs it through multiple output ports. It converts the analog signals transmitted from the signal receiving unit 41 into digital signals and calculates the pressure value corresponding to each pressure test sub-range 202 according to the preset calibration curve of each pressure testing unit (such as factory calibration or field calibration). Then, it outputs each pressure value independently through its output port. Independent output means that each pressure value is output through different output channels or different data frames, rather than merging all pressure values ​​into a single total pressure value. To ensure that the pressure values ​​output by each pressure testing unit accurately reflect the actual stress on the aluminum foam 100 sample, it is recommended that each pressure testing unit be calibrated step by step using a standard force measuring machine before being assembled into the support assembly 20. This will establish a correspondence between the output electrical signal of each pressure testing unit and the actual applied pressure value, thus obtaining the preset calibration relationship for each pressure testing unit. These preset calibration relationships will then be stored in the storage module of the control unit 42, with each pressure testing unit's channel number bound to its corresponding preset calibration relationship.

[0026] Furthermore, considering that the pressure sensor's testing accuracy may be affected by creep, temperature drift, or performance degradation during long-term use, it is recommended to perform on-site calibration of the testing device: Place standard force transmission blocks in each pressure test sub-section 202 of the pressure test section 201, activate the pressurization mechanism 10 to apply known standard pressure values ​​to each standard force transmission block, and the control unit 42 compares the actual output value of each pressure test unit with the theoretical output value, calculates the correction coefficient for each channel, and updates the corresponding preset calibration relationship in the storage module. The recommended calibration cycle for on-site calibration is once every three months or once after every 500 tests to maintain the long-term testing accuracy of each pressure test unit. The above calibration methods are suggestions for the use of the device; those skilled in the art can adjust them according to actual usage conditions.

[0027] On-site calibration refers to the process of eliminating the impact of factors such as sensor creep, temperature drift, or performance degradation caused by long-term use on the test accuracy during long-term use of the testing device. The device of this invention also supports on-site calibration. During on-site calibration, standard force transmission blocks are placed in each pressure test sub-section 202 of the pressure test section 201. The pressurization mechanism 10 is activated to apply known standard pressure values ​​to each standard force transmission block. The control unit 42 compares the actual output value of each pressure test unit with the theoretical output value, calculates the correction coefficient for each channel, and automatically updates the corresponding calibration curve parameters in the storage module. The preferred calibration cycle for on-site calibration is once every three months or once after every 500 tests to maintain the long-term test accuracy of each pressure test unit.

[0028] In one embodiment, each pressure testing unit is embedded in the surface of the support assembly 20 facing the pressurizing mechanism 10, and is located in the geometric center region of the corresponding pressure testing sub-section 202. Specifically, the support assembly 20 has mounting slots on one side of its surface facing the pressurizing mechanism 10, the number of which is the same as the number of pressure testing units. Each mounting slot has a wire-passing hole at its bottom, which passes through the support assembly 20 and extends to the back of the support assembly 20. Each pressure testing unit is housed in its corresponding mounting slot, and the pressure-sensing surface of each pressure testing unit is flush with or slightly higher than the surface of the support assembly 20 (the protrusion is controlled within the range of 0.1 mm to 0.5 mm) to ensure that the pressure testing unit can fully contact the back of the aluminum foam 100 sample.

[0029] The sidewalls of each mounting slot and the outer wall of the pressure testing unit are filled with an elastic fixing adhesive, such as epoxy resin or silicone rubber. This adhesive reliably secures the pressure testing unit within the mounting slot and also provides cushioning protection during pressurization, preventing sensor damage due to impact loads. The signal leads of each pressure testing unit are led out through corresponding through-holes to the back of the support assembly 20 and electrically connected to the corresponding input terminal of the signal receiving unit 41. The through-holes are filled with sealant to prevent debris or dust generated during testing from entering and affecting the reliability of signal transmission.

[0030] In addition, each mounting slot is equipped with a limiting pressure plate, which is fixed to the surface of the support assembly 20 by screws. A clearance hole is provided in the center of the limiting pressure plate. The diameter of the clearance hole is smaller than the outer diameter of the pressure testing unit but larger than the diameter of the pressure-sensing surface of the pressure testing unit. The limiting pressure plate presses against the edge area of ​​the pressure testing unit to prevent it from loosening from the mounting slot due to repeated pressure during long-term use. Through the triple fixing method of the mounting slot's positioning, the elastic adhesive's bonding, and the mechanical limiting of the limiting pressure plate, the installation position of each pressure testing unit on the support assembly 20 is ensured to be accurate and stable over a long period.

[0031] Furthermore, in this invention, the pressure transmission path between the pressure testing unit and the aluminum foam 100 sample is a direct contact transmission, meaning that the pressure-sensing surface of each pressure testing unit directly contacts the back surface of the aluminum foam 100 sample. When the pressurizing mechanism 10 squeezes the aluminum foam 100 sample from the front, the extrusion force is transmitted through the aluminum foam 100 sample body to its back surface, directly acting on the pressure-sensing surface of each pressure testing unit. This direct contact transmission path avoids the force transmission loss, force deflection, or additional non-test-oriented stress on the sample surface that might be introduced by adding intermediate force transmission components in the pressure transmission path, ensuring that the pressure values ​​detected by each pressure testing unit can truly and accurately reflect the actual pressure borne by each local area of ​​the aluminum foam 100 sample. In addition, the ratio of the area of ​​the pressure-sensing surface of each pressure testing unit to the area of ​​the corresponding pressure testing sub-interval 202 is 1:3 to 1:5, ensuring that the pressure-sensing surface has sufficient pressure receiving area to obtain a stable pressure signal, while avoiding signal interference between adjacent pressure testing sub-intervals 202 due to an excessively large pressure-sensing surface.

[0032] In the technical solution provided by this invention, the pressure test interval 201 is divided into multiple independent pressure test sub-intervals 202 by using the installation component 30, and a corresponding pressure test unit is set in each sub-interval. Combined with the signal receiving unit 41 and the control unit 42, the pressure signals of each sub-interval are independently acquired and output separately, enabling accurate acquisition of the compressive strength data of each local area of ​​the aluminum foam 100 sample. Because the internal pore structure of the aluminum foam 100 material is heterogeneous, the stress state of different areas varies significantly when the whole is under pressure. The multi-point independent pressure measurement method of this invention can effectively capture this local difference, providing more comprehensive and accurate test data for the compressive performance evaluation of the aluminum foam 100 anti-collision beam, and helping to identify internal defects in the material.

[0033] In one embodiment, the diameters of the plurality of upper mounting posts 31 and the plurality of lower mounting posts 32 are all reduced in diameter from the support assembly 20 toward the pressurizing mechanism 10. That is, the diameter of each mounting post is larger at the end near the support assembly 20 and smaller at the end away from the support assembly 20, i.e., near the pressurizing mechanism 10, forming an overall conical or truncated conical structure. Taking one of the upper mounting posts 31 as an example, the diameter of the end fixed to the surface of the support assembly 20 is the first diameter, and the diameter of its free end is the second diameter, which is smaller than the first diameter. The cross-sectional shape of the mounting post can be circular, elliptical, or polygonal. This reduced-diameter structure provides a guiding function for the insertion of the aluminum foam 100 sample, facilitating the smooth horizontal insertion of the aluminum foam 100 sample into each pressure test sub-section 202. Specifically, because the diameter of the mounting post near the pressure mechanism 10 is smaller, the gap between two adjacent mounting posts is larger at the end near the pressure mechanism 10, allowing the end of the sample to easily enter this gap. As the sample continues to be pushed in, the gap gradually decreases, and the contact between the sample and the mounting post gradually tightens, eventually being reliably clamped and positioned at the predetermined location. This structure avoids the edge of the aluminum foam 100 sample from cracking or being damaged due to excessive clamping force or squeezing of edge corners.

[0034] The aluminum foam 100 sample and the mounting assembly 30 form a plug-in detachable fit. The aluminum foam 100 sample can be slid into the horizontal direction between two adjacent upper mounting posts 31 and between two corresponding adjacent lower mounting posts 32. When the sample is fully pushed in, its back side is in contact with the pressure-sensing surface of each pressure test unit, and its front side faces the pressure mechanism 10. The assembly and disassembly process does not require additional tools and is easy to operate.

[0035] Please continue reading. Figure 1 And see Figure 2In one embodiment, the pressurizing mechanism 10 includes a driving member 11, a pressurizing assembly 12, a base plate 13, and a guide assembly 14. The driving member 11 is spaced apart from the support assembly 20, and the pressurizing assembly 12 extends horizontally and is disposed between the driving member 11 and the support assembly 20. The pressurizing assembly 12 is positioned corresponding to the pressure test zone 201, that is, the extrusion end of the pressurizing assembly 12 faces the center region of the pressure test zone 201. The output end of the driving member 11 is connected to the pressurizing assembly 12 to provide driving force to the pressurizing assembly 12. The pressurizing assembly 12 is connected to the guide assembly 14, and the guide assembly 14 is slidably engaged with the base plate 13 to guide and limit the movement of the pressurizing assembly 12, ensuring the straightness of the reciprocating movement of the pressurizing assembly 12 in the horizontal direction.

[0036] The driving component 11 can be a rotary motor, linear motor, hydraulic motor, or manual drive device. In this embodiment, the driving component 11 is preferably a servo motor, which facilitates precise control of the pressurization speed and displacement. The driving component 11 is fixedly installed at one end of the base plate 13, and the support assembly 20 is fixedly installed at the other end of the base plate 13. The distance between the driving component 11 and the support assembly 20 is greater than the total length of the aluminum foam 100 sample and the pressurization assembly 12 to provide sufficient pressurization stroke.

[0037] Please continue reading. Figure 2The pressurizing assembly 12 includes a mounting base 121, a screw 122, a pressurizing rod 123, and two sleeves 124. The mounting base 121 is located near the support assembly 20 and supports the end of the screw 122. The mounting base 121 is fixed to the base plate 13 and has a bearing inside, through which the end of the screw 122 is rotatably connected to the mounting base 121. The screw 122 extends horizontally and has a first threaded section 1221 and a second threaded section 1222 formed on it. The first threaded section 1221 and the second threaded section 1222 have the same direction of rotation, for example, both are right-hand threads or both are left-hand threads. One end of the screw 122 is connected to the output shaft of the drive member 11 via a coupling and is driven to rotate by the drive member 11. Two sleeves 124 are respectively fitted onto the outside of the first threaded section 1221 and the second threaded section 1222 of the screw 122, and the inner walls of the two sleeves 124 are respectively provided with internal threads that are adapted to the first threaded section 1221 and the second threaded section 1222, forming a threaded fit. A pressure rod 123 is installed on the top of the two sleeves 124, that is, the pressure rod 123 extends in a direction perpendicular to the axial direction of the screw 122 and spans the two sleeves 124. Both ends of the pressure rod 123 are fixedly connected to the two sleeves 124 and move together with the sleeves 124. When the driving member 11 drives the screw 122 to rotate, the two sleeves 124 move synchronously along the axial direction of the screw 122 in a direction closer to or away from the support assembly 20, so that the pressure rod 123 fixed on the sleeves 124 either compresses the aluminum foam 100 sample into the pressure test zone 201 or releases the aluminum foam 100 sample into the pressure test zone 201.

[0038] Since the first threaded section 1221 and the second threaded section 1222 have the same direction of rotation, when the screw 122 rotates, the two sleeves 124 move synchronously in the same direction on their respective corresponding threaded sections. The synchronous movement of the two sleeves 124 ensures that the pressure rod 123 installed on top of them always maintains its initial posture parallel to itself during the movement, preventing the pressure rod 123 from tilting during the movement, thereby ensuring that the compressive force applied by the pressure rod 123 to the aluminum foam 100 sample is stable and evenly distributed.

[0039] Please see Figure 2In one embodiment, the pressure rod 123 has a mounting hole 101 on the side facing the pressure test zone 201. The pressure assembly 12 also includes a pressure head 125, which extends horizontally, and has a pressure end and a connecting end at its two ends along its extension direction, respectively. The connecting end is provided with an external thread that mates with the internal thread of the mounting hole 101, and the connecting end is screwed into the mounting hole 101 to achieve detachable fixation between the pressure head 125 and the pressure rod 123. The pressure end has an arc-shaped or spherical structure that arches towards the pressure test zone 201. When the pressure rod 123 moves the pressure head 125 toward the aluminum foam 100 sample, the arc-shaped or spherical pressure end first contacts the surface of the aluminum foam 100 sample.

[0040] The arc-shaped or spherical pressure end forms line or point contact with the aluminum foam 100 sample, effectively avoiding localized stress concentration on the aluminum foam 100 surface caused by the sharp edges of traditional flat pressure ends. This prevents abnormal breakage of the aluminum foam 100 sample due to stress concentration in the initial stage of pressure application. This is particularly important for brittle and porous materials like aluminum foam 100, ensuring that the failure mode of the sample during testing is overall compressive failure rather than localized shear failure, thus guaranteeing the accuracy of the test results. Simultaneously, the threaded connection between the connecting end and the mounting hole 101 allows operators to quickly change pressure heads 125 of different shapes or sizes according to different testing needs.

[0041] Please continue reading. Figure 1 In one embodiment, the guide assembly 14 includes two guide blocks 141, and a guide groove 102 is formed on the top of the base plate 13. The guide groove 102 extends axially along the screw 122, and its cross-sectional shape can be a T-groove, dovetail groove, or rectangular groove. Both guide blocks 141 extend vertically and are spaced apart along the extension direction of the screw 122. The bottom ends of the two guide blocks 141 extend into the guide groove 102 and slide in cooperation with the guide groove 102. For example, the bottom ends of the guide blocks 141 are provided with protrusions or slider structures adapted to the shape of the guide groove 102. The top ends of the two guide blocks 141 are fixedly connected to two sleeves 124 respectively. When the screw 122 drives the sleeves 124 to move horizontally, the sleeves 124 drive the guide blocks 141 connected to them to move together, and the bottom ends of the guide blocks 141 slide within the guide groove 102.

[0042] The sliding fit between the guide block 141 and the guide groove 102 provides good guidance and limiting for the movement of the sleeve 124 and the pressure rod 123 fixed on the sleeve 124. This structure effectively prevents the pressure assembly 12 from rotating or swaying around the axis of the screw 122 during movement, ensuring that the pressure rod 123 and the pressure head 125 always compress the aluminum foam 100 sample in the correct horizontal direction, thus improving the repeatability and accuracy of the test.

[0043] Please see Figure 1 , Figure 3 and Figure 4 In one embodiment, the support assembly 20 includes a support plate 21 and a back brace 22. The support plate 21 extends vertically and has a pressure test zone 201 corresponding to the position of the pressurizing mechanism 10. The support plate 21 is made of high-strength steel plate or cast iron and has sufficient rigidity and flatness. The back brace 22 is installed on the side of the support plate 21 away from the pressurizing mechanism 10, and the back brace 22 is inclined away from the support plate 21 in a direction away from the pressurizing mechanism 10. Specifically, the top end of the back brace 22 is fixed to the top area of ​​the support plate 21 by welding or bolting, and the bottom end of the back brace 22 extends obliquely downward in a direction away from the pressurizing mechanism 10 and is supported on the base plate 13 or the ground. The back brace 22 can be a single diagonal brace or multiple diagonal braces arranged in parallel. In this way, a triangular support area is formed between the support plate 21 and the inclined back brace 22, which effectively enhances the overall structural rigidity of the support assembly 20 by utilizing the geometric stability principle of a triangle.

[0044] When the pressurizing mechanism 10 applies a large compressive force to the aluminum foam 100 sample, the support plate 21 bears the reaction force from the sample. If the rigidity of the support plate 21 is insufficient, it may bend and deform, causing the measurement reference plane of the pressure test unit to shift and introducing measurement errors. By setting the inclined back support 22, the reaction force is effectively transferred and dispersed to the base plate 13 or the ground, ensuring the morphological stability of the support plate 21 during the test, thereby ensuring the consistency of the measurement reference of each pressure test unit and the accuracy of the test data.

[0045] In one embodiment, the control unit 42 is further configured to generate a compressive strength distribution map of the aluminum foam 100 sample based on each pressure value. The control unit 42 correlates the position coordinates of each pressure test sub-interval 202 with its corresponding pressure value, displaying the compressive strength distribution of each local area on a display screen in the form of a two-dimensional color cloud map or a three-dimensional bar chart, where different colors or bar heights correspond to different pressure value intervals. This compressive strength distribution map can intuitively show the differences in compressive strength of different local areas of the aluminum foam 100 sample, helping inspectors quickly identify weak areas or defect locations within the sample.

[0046] Furthermore, for ease of understanding, a specific implementation is shown here. The test device is assembled according to the structure of any of the above embodiments. The power connection and signal connection of the drive unit 11, signal receiving unit 41 and control unit 42 are checked to ensure that they are normal, and the zero point calibration of each pressure test unit is confirmed to be correct.

[0047] A sample of aluminum foam 100 is inserted horizontally between the upper mounting post 31 and the lower mounting post 32 of the mounting assembly 30, so that the sample covers at least one pressure test sub-section 202, with the back of the sample in contact with the pressure-sensing surface of each pressure test unit. If the size of the sample is larger than the size of a single pressure test sub-section 202, the sample covers multiple pressure test sub-sections 202 simultaneously.

[0048] The pressurizing mechanism 10 is activated, causing the pressurizing rod 123 to move horizontally toward the support assembly 20, compressing the aluminum foam 100 sample. Specifically, the drive unit 11 is activated, driving the screw 122 to rotate. Under the threaded drive of the screw 122, the two sleeves 124 move synchronously horizontally toward the support assembly 20. The sleeves 124 drive the pressurizing rod 123 and the pressurizing head 125 to move synchronously. The arc-shaped or spherical pressurizing end of the pressurizing head 125 gradually contacts the front of the aluminum foam 100 sample and applies gradually increasing compressive force. The pressurizing speed is recommended to be set to 0.5 mm to 2 mm per minute. For aluminum foam 100 material, the preferred pressurizing speed is 1 mm per minute: the pore structure of aluminum foam requires a certain amount of time to complete the deformation response under pressure. If the loading speed is too fast, the sample will not have enough time to deform fully, and the measured data will deviate from its quasi-static compressive strength; if the loading speed is too slow, it will affect the detection efficiency. The above-mentioned pressurization rate is a theoretically recommended value based on the deformation response characteristics of aluminum foam material. Those skilled in the art can adjust it according to test standards or actual usage conditions.

[0049] Each pressure testing unit collects independent pressure signals from its corresponding pressure testing sub-section 202 and transmits these signals to the signal receiving unit 41. Since each pressure testing unit is positioned in a corresponding sub-section 202, each unit independently detects the pressure experienced by its corresponding local area. The channels are isolated from each other and do not interfere with each other. The pressure testing unit converts the sensed pressure into analog voltage or analog current signals, which are then transmitted to the input terminals of the signal receiving unit 41 via wires.

[0050] The signal receiving unit 41 transmits each independent pressure signal to the control unit 42. The control unit 42 generates a pressure value corresponding to each pressure test sub-range 202 based on each independent pressure signal and outputs each pressure value independently. The analog-to-digital converter module built into the control unit 42 converts the analog signals of each channel into digital signals. The microprocessor calculates the actual pressure value of each sub-range based on the preset calibration curve of each pressure test unit (such as factory calibration or field calibration), and then outputs each pressure value to the display device or data recording device with different data identifiers through different output ports or through the same communication interface.

[0051] Specifically, the process by which the control unit 42 generates the compressive strength distribution map includes the following steps: Step S1: The control unit 42 acquires the planar coordinate data of the geometric center of each pressure test sub-section 202 within the pressure test section 201. The planar coordinate data of each pressure test sub-section 202 is pre-stored in the storage module of the control unit 42, and each coordinate data is bound to the channel number of the corresponding pressure test unit.

[0052] Step S2: The control unit 42 calculates the pressure value Pi (i=1,2,…,n, where n is the total number of pressure test sub-intervals 202) corresponding to each pressure test sub-interval 202 based on the independent pressure signal output by each pressure test unit.

[0053] Step S3: The control unit 42 calculates the compressive strength value σi = Pi / Si corresponding to each pressure test sub-interval 202 based on the area Si of each pressure test sub-interval 202. If the aluminum foam 100 sample only covers part of the pressure test sub-interval 202, the pressure value detected by the pressure test unit corresponding to the uncovered sub-interval is zero or close to zero. The control unit 42 automatically discards this data and only calculates the compressive strength and generates the distribution map for the pressure test sub-interval 202 actually covered by the aluminum foam 100 sample.

[0054] Step S4: The control unit 42 associates the planar coordinate data of each pressure test sub-interval 202 with its corresponding compressive strength value σi to construct a two-dimensional discrete data point set {(xi, yi, σi)}.

[0055] Step S5: The control unit 42 processes the two-dimensional discrete data point set using an interpolation algorithm to generate continuously distributed two-dimensional compressive strength distribution data. The interpolation algorithm is selected from any one of inverse distance weighted interpolation, Kriging interpolation, or radial basis function interpolation. Taking inverse distance weighted interpolation as an example, for any interpolation point (x, y), the formula for calculating the compressive strength value σ(x, y) is: σ(x, y) = [Σ(σi / di^p)] / [Σ(1 / di^p)] Where di is the Euclidean distance from the interpolation point (x, y) to the i-th data point (xi, yi), and p is the power exponent (ranging from 1 to 3, preferably 2).

[0056] Step S6: The control unit 42 generates a compressive strength distribution map according to the interpolated two-dimensional compressive strength distribution data and a preset color mapping rule. The color mapping rule is as follows: the compressive strength values ​​are divided into several continuous numerical intervals from minimum to maximum, each interval corresponding to a color. The larger the value, the darker the corresponding color (e.g., a gradient from blue to red), thus visually displaying the compressive strength distribution of various local areas of the aluminum foam 100 sample in the form of a two-dimensional color cloud map. The control unit 42 outputs the generated compressive strength distribution map to a display device electrically connected to the control unit 42 for display.

[0057] Furthermore, the control unit 42 is also used to calculate the standard deviation of compressive strength δ = sqrt[Σ(σi - σavg)2 / n] based on the compressive strength values ​​of each pressure test sub-interval 202, where σavg is the arithmetic mean of the compressive strength values ​​of all pressure test sub-intervals 202. When the standard deviation of compressive strength δ exceeds a preset threshold, the control unit 42 generates a defect indication signal and alerts the testing personnel through a display device or alarm device that there is significant non-uniformity in compressive strength inside the aluminum foam 100 sample, and that there may be local defects.

[0058] Furthermore, the technical advantages of this application's solution for non-destructive clamping and multi-point independent pressure measurement of aluminum foam samples are as follows: Firstly, regarding non-destructive clamping: The diameters of the multiple upper mounting posts 31 and multiple lower mounting posts 32 are all tapered from the support assembly 20 toward the pressure mechanism 10, so that the gap between two adjacent mounting posts gradually narrows from the side closer to the pressure mechanism 10 toward the side closer to the support assembly 20. The sample end can easily enter from the side with the wider gap, and is limited by the gradually narrowing gap during the pushing process. Reliable sample positioning can be achieved without the need for additional clamping mechanisms or concentrated clamping force on the edges of the sample, fundamentally avoiding the breakage and damage of brittle sample edges due to concentrated clamping force.

[0059] Secondly, regarding the stability of the measurement reference. The pressure test unit is embedded in the mounting groove of the support component 20 and located in the geometric center region of the corresponding pressure test sub-section 202. Its pressure-sensing surface is flush with or slightly higher than the surface of the support component 20 by 0.1mm to 0.5mm. Elastic fixing adhesive is filled between the side wall of the mounting groove and the outer wall of the pressure test unit. The limiting pressure plate is pressed onto the edge of the pressure test unit through the clearance hole. The three together constrain the spatial position of the pressure test unit, so that it maintains its initial installation position and posture under repeated pressure impacts, and the measurement reference does not shift. The pressure-sensing surface is located at the geometric center of the sub-section, so that the pressure value detected is closer to the average stress state in the sub-section, reducing the deviation introduced by the edge effect.

[0060] Thirdly, regarding signal independence: The ratio of the area of ​​the pressure-sensing surface to the area of ​​the pressure test sub-section 202 is 1:3 to 1:5, ensuring that the pressure-sensing surface has sufficient receiving area to obtain a stable signal, while maintaining sufficient spacing between the pressure-sensing surfaces of adjacent sub-sections, structurally avoiding signal crosstalk; the output terminal of each pressure test unit is electrically connected to each input terminal of the signal receiving unit 41, and the signal leads of each pressure test unit are led to the back of the support assembly 20 through their respective wire holes. The control unit 42 outputs each pressure value through multiple output ports. The entire process of pressure information from each sub-section from sensing pressure to output is structurally isolated and does not merge with each other, thereby ensuring that each pressure value output truly corresponds to the stress state of each sub-section.

[0061] Therefore, the device of this application can stably obtain the pressure values ​​of each local area of ​​the aluminum foam sample without damaging the sample, realize the independent characterization of the compressive strength distribution of the sample, provide a reliable structural basis for identifying the local strength differences caused by the heterogeneous distribution of internal pores in aluminum foam materials, and provide a more comprehensive and accurate testing method for evaluating the compressive performance of aluminum foam anti-collision beams.

[0062] The above description is merely an embodiment of the present invention and does not limit the scope of protection of the present invention. Any equivalent structural transformations made under the technical concept of the present invention using the contents of the specification and drawings of the present invention, or direct / indirect applications in other related technical fields, are included within the scope of protection of the present invention.

Claims

1. A device for testing the compressive strength of foamed aluminum anti-collision beams, characterized in that, include: Pressurization mechanism; A support assembly is provided, which is horizontally spaced from the pressurizing mechanism, and a pressure test zone is provided on the side of the support assembly facing the pressurizing mechanism; The mounting assembly includes multiple upper mounting columns and multiple lower mounting columns. The upper mounting columns are spaced apart along the upper edge of the pressure test interval, and the lower mounting columns are spaced apart along the lower edge of the pressure test interval. The number of upper mounting columns and lower mounting columns is the same and they are arranged in a one-to-one correspondence. A pressure test sub-interval is formed between two adjacent upper mounting columns and two corresponding lower mounting columns. Multiple pressure test sub-intervals are formed between the multiple upper mounting columns and the multiple lower mounting columns. The diameters of the multiple upper mounting columns and the multiple lower mounting columns decrease from the support assembly toward the pressurizing mechanism. The pressure testing module includes a signal receiving unit, a control unit, and multiple pressure testing units. The number of pressure testing units corresponds to the number of pressure testing sub-sections. The aluminum foam is detachably inserted and covers at least one corresponding pressure testing sub-section via at least two upper mounting posts and at least two corresponding lower mounting posts. Each pressure testing unit is embedded in a mounting groove on the side surface of the support assembly facing the pressurizing mechanism and is located at the geometric center of its corresponding pressure testing sub-section. A wire-passing hole is provided at the bottom of the mounting groove, penetrating the support assembly and extending to its back. Elastic adhesive is filled between the sidewall of the mounting groove and the outer wall of the pressure testing unit. A limiting plate is provided at the opening of the mounting groove, and an clearance hole is provided in the middle of the limiting plate. The diameter of the clearance hole is smaller than that of the pressure testing sub-section. The outer diameter of the test unit is larger than the diameter of the pressure-sensing surface of the pressure test unit. The pressure-sensing surface of the pressure test unit is flush with or 0.1 mm to 0.5 mm higher than the surface of the support assembly. The ratio of the area of ​​the pressure-sensing surface of the pressure test unit to the area of ​​the corresponding pressure test sub-interval is 1:3 to 1:

5. The signal receiving unit is disposed on the support assembly and has multiple input terminals. The output terminals of the multiple pressure test units are respectively connected to the multiple input terminals of the signal receiving unit. The signal receiving unit is used to receive the independent pressure signals generated by each pressure test unit. The control unit is disposed on the support assembly and is electrically connected to the signal receiving unit. The control unit is used to generate pressure values ​​corresponding to each pressure test sub-interval based on the received independent pressure signals and to output each pressure value independently.

2. The device for testing the compressive strength of foamed aluminum anti-collision beams as described in claim 1, characterized in that, The pressurizing mechanism includes a driving component, a pressurizing component, a base plate, and a guide component. The driving component and the support component are spaced apart. The pressurizing component extends horizontally and is disposed between the driving component and the support component. The pressurizing component is positioned corresponding to the pressure test range. The output end of the driving component is connected to the pressurizing component. The pressurizing component is connected to the guide component. The guide component slides with the base plate.

3. The device for testing the compressive strength of foamed aluminum anti-collision beams as described in claim 2, characterized in that, The pressurizing assembly includes a mounting base, a screw, a pressure rod, and two sleeves. The mounting base is located close to the support assembly. The screw extends horizontally and has a first threaded section and a second threaded section formed on it. The first threaded section and the second threaded section have the same direction of rotation. One end of the screw is connected to the output end of the drive member, and the other end of the screw is rotatably mounted on the mounting base. The two sleeves are sleeved on the screw and threadedly connected to the first threaded section and the second threaded section, respectively. The pressure rod is mounted on the top of the two sleeves. The drive member is used to drive the screw to rotate, causing the two sleeves to move along the axial direction of the screw towards or away from the support assembly, so that the pressure rod squeezes the aluminum foam into the pressure test zone or releases the aluminum foam into the pressure test zone.

4. The device for testing the compressive strength of foamed aluminum anti-collision beams as described in claim 3, characterized in that, The pressure rod has a mounting hole on one side facing the pressure test zone. The pressure assembly also includes a pressure head that extends horizontally. The two ends of the pressure head along its extension direction form a pressure end and a connection end, respectively. The connection end is threaded to the mounting hole. The pressure end has an arc-shaped structure or a spherical structure that arches towards the pressure test zone.

5. The device for testing the compressive strength of foamed aluminum anti-collision beams as described in claim 3, characterized in that, The guiding assembly includes two guide blocks. A guide groove is provided on the top of the base plate. Both guide blocks extend vertically and are spaced apart along the extension direction of the screw. The bottom ends of the two guide blocks extend into the guide groove and slide in cooperation with the guide groove. The top ends of the two guide blocks are respectively connected to the two sleeves.

6. The device for testing the compressive strength of foamed aluminum anti-collision beams as described in claim 1, characterized in that, The support assembly includes a support plate and a back support. The support plate extends vertically and has a pressure test area corresponding to the position of the pressurizing mechanism. The back support is installed on the side of the support plate away from the pressurizing mechanism and is inclined away from the support plate in a direction away from the pressurizing mechanism.

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