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CN-121977911-A - Standardized sample preparation device and sample preparation method based on coral sand SHPB test

CN121977911ACN 121977911 ACN121977911 ACN 121977911ACN-121977911-A

Abstract

The invention relates to a standardized sample preparation device and method based on coral sand SHPB test, comprising a base, a bottom cushion block arranged above the base, and a sleeve arranged above the bottom cushion block, wherein a hammer seat abutting against the upper part of a sample is arranged in the sleeve, the hammer seat is movably connected with a compaction hammer in the vertical direction, and a limiting piece is arranged on the compaction hammer. The invention adapts to sample preparation requirements of non-sticky and weak-sticky sandy soil such as coral sand, calcareous sand and the like, combines a thermal shrinkage film packaging technology, can regulate and control passive confining pressure when a sample is impacted in a mode of overlapping a plurality of layers of thermal shrinkage films, realizes accurate reduction of test working conditions and actual engineering scenes, expands the application range of the device, realizes accurate limiting and leveling in a compaction process through standardized structural design, ensures sample compaction uniformity and cushion block flatness, simplifies sample preparation flow, improves sample preparation efficiency, avoids damage of SHPB test equipment, and has universality and practicability.

Inventors

  • LIU TINGTING
  • HUANG WENXU
  • LI XINPING
  • LI WENHAO
  • Pan Zhenkai

Assignees

  • 武汉理工大学三亚科教创新园

Dates

Publication Date
20260505
Application Date
20260409

Claims (9)

  1. 1. The standardized sample preparation device based on the coral sand SHPB test is characterized by comprising a base (1), a bottom pad block (2) arranged above the base (1) and a sleeve (3) arranged above the bottom pad block (2) and used for placing a sample (9), wherein a hammer seat (4) abutted to the upper part of the sample (9) is arranged in the sleeve (3), the hammer seat (4) is movably connected with a compaction hammer (8) in the vertical direction, and a limiting piece (5) used for limiting the falling distance of the compaction hammer (8) is arranged on the compaction hammer (8); the outer wall of the compaction hammer (8) is provided with a mounting hole (81), a limiting piece (5) is detachably connected in the mounting hole (81), and the limiting piece (5) is located above the sleeve (3).
  2. 2. The standardized sample preparation device based on coral sand SHPB test according to claim 1, wherein a vertically extending bracket (6) is arranged on the base (1), the bracket (6) is movably connected with a leveling piece (7) in the vertical direction, the upper part of the hammer seat (4) is movably connected with the leveling piece (7) in the vertical direction, one end of a barrel support arm (31) is connected on the sleeve (3), and the other end of the barrel support arm (31) is movably connected on the bracket (6) in the vertical direction.
  3. 3. The standardized sample preparation device based on coral sand SHPB test of claim 2, wherein a lower limit clamping piece (32) is arranged at the movable connecting end of the barrel support arm (31) and the bracket (6).
  4. 4. Standardized sample preparation device based on coral sand SHPB test according to claim 2, characterized in that the hammer seat (4) comprises a hammer plate (41) and a hammer rod (42), the leveling piece (7) comprises a hollow leveling ring (71) and a leveling arm (72), the bottom of the hammer plate (41) is abutted with the sample (9), the hammer rod (42) penetrates through the leveling ring (71) and is movably connected with the leveling ring (71), one end of the leveling arm (72) is connected with the leveling ring (71), and the other end is movably connected with the bracket (6).
  5. 5. The standardized sample preparation device based on coral sand SHPB test as defined in claim 4, wherein an upper limit clamping piece (73) is arranged at the movable connecting end of the leveling arm (72) and the bracket (6).
  6. 6. The standardized sample preparation device based on the coral sand SHPB test of claim 4, wherein the compaction hammer (8) has a hollow structure, and the hammer rod (42) penetrates through a hollow region of the compaction hammer (8) and is movably connected with the compaction hammer (8).
  7. 7. A standardized sample preparation device based on a coral sand SHPB test as defined in claim 5, wherein the plurality of holders (6) is provided in plural numbers corresponding to the leveling arm (72) and the drum arm (31).
  8. 8. The standardized sample preparation device based on the coral sand SHPB test according to claim 1, wherein the mounting holes (81) are provided in a plurality of spaced apart positions in the axial direction and the circumferential direction of the compaction hammer (8).
  9. 9. A sample preparation method based on the sample preparation device according to claim 1, comprising the steps of: preparing a sample, namely preparing coral sand (93) with the required grading after screening, drying, uniformly stirring for standby, cutting a heat shrinkage film (91) with the corresponding size, and polishing and cleaning a plurality of sample cushion blocks (92) for standby; The heat shrinkage film mold is prepared by vertically stacking a plurality of sample cushion blocks (92), sleeving all the sample cushion blocks (92) on a heat shrinkage film (91) from top to bottom, blowing the sample cushion blocks (92) by using a hot air gun, integrally overturning after the heat shrinkage film (91) is firmly molded, sequentially taking out redundant sample cushion blocks (92) from the upper part, and reserving one sample cushion block (92) at the bottom; Filling and compacting coral sand (93), namely pouring the prepared coral sand (93) into a heat-shrinkable film (91) mold for a plurality of times, and compacting the coral sand (93) in the heat-shrinkable film (91) mold for a plurality of times through a sample preparation device; And (3) packaging the sample (9), namely additionally placing a sample cushion block (92) above the compaction formed sample (9), and uniformly blowing air to the upper part of the heat shrinkage film (91) by using a hot air gun to firmly attach the heat shrinkage film (91) to the sample cushion block (92) above to finish the packaging of the sample (9).

Description

Standardized sample preparation device and sample preparation method based on coral sand SHPB test Technical Field The invention relates to the technical field of Hopkinson bar test, in particular to a standardized sample preparation device and method based on coral sand SHPB test, which are suitable for standardized sample preparation of SHPB dynamic impact test of non-sticky granular sandy soil such as coral sand, calcareous sand and the like, and can also be suitable for standardized preparation of granular samples of various geotechnical tests. Background Loose granular sand such as coral sand and calcareous sand is widely applied to sea engineering construction such as sea island reef body hydraulic filling, airport runway roadbed and the like due to convenient material taking and low economic cost, the mechanical properties of the sand under power disturbance working conditions such as airplane take-off and landing, weapon striking, piling and the like are key basis for engineering design and safety evaluation, related mechanical parameters are required to be measured through a Hopkinson bar (SHPB) power impact test, meanwhile, the coral sand is used as an excellent energy absorbing and consuming material, and high requirements are also provided for the standardization degree of test samples by the performance test under the power impact. In the prior art, when an SHPB test of loose sand such as coral sand, calcareous sand and the like is carried out, a sample preparation mode of clamping a sand sample by adopting an external steel sleeve and a steel cushion block is adopted, and the sample preparation mode has the technical defects that firstly, uniformity of compactness of the sand sample in the steel sleeve cannot be guaranteed in the sample preparation process, the cushion block lacks a stable fixed structure, compaction force cannot be controlled accurately, meanwhile, flatness of the cushion block cannot be guaranteed, damage of SHPB test equipment is easily caused, secondly, passive confining pressure applied to the sample in an impact test cannot be quantified and regulated, so that test data discreteness is large, practical engineering such as surface coral sand and the like is difficult to reduce, thirdly, sample preparation and sample loading processes are complicated, operation efficiency is low, water-containing samples cannot be prepared, and diversity of test working conditions is limited, fourthly, the existing sample preparation device lacks standardized limiting and leveling structures, the falling distance and the compaction angle of a hammer in the compaction process cannot be controlled accurately, further, quality of the sample is uneven, and reliability of test results is difficult to guarantee. To the above-mentioned problem, it is urgent to develop a standardized sample preparation device that possesses accurate spacing, leveling function, can realize that sample compactness, moisture content quantization control, passive confining pressure are adjustable to satisfy loose calcareous sand SHPB test's system appearance demand, promote test data's accuracy and reliability, improve system appearance efficiency simultaneously, reduce test cost. Disclosure of Invention The invention aims to overcome the defects in the prior art, and provides a standardized sample preparation device and method based on a coral sand SHPB test, which realize accurate limit and leveling in a compaction process through a standardized structural design, ensure the compactness and uniformity of a sample and the flatness of a cushion block, quantitatively control the compactness and the moisture content of the sample, adapt to the sample preparation requirement of passive confining pressure control, simplify the sample preparation process, improve the sample preparation efficiency, avoid the damage of SHPB test equipment, adapt to the sample preparation requirement of various non-sticky and weak-sticky sand, and have universality and practicability. In order to achieve the above purpose, the present invention adopts the following technical scheme: The standardized sample preparation device based on the coral sand SHPB test comprises a base, a bottom cushion block arranged above the base, and a sleeve arranged above the bottom cushion block and used for placing a sample, wherein a hammer seat which is abutted to the upper part of the sample is arranged in the sleeve, the hammer seat is movably connected with a compaction hammer in the vertical direction, and a limiting piece used for limiting the falling distance of the compaction hammer is arranged on the compaction hammer; The outer wall of the compaction hammer is provided with a mounting hole, a limiting piece is detachably connected in the mounting hole, and the limiting piece is located above the sleeve. Further, a vertically extending support is arranged on the base, a leveling piece is movably connected to the support in the vertical direction, the u