CN216669511U - Clamp for testing shearing performance of composite material - Google Patents

Abstract

The utility model provides a anchor clamps for testing combined material shearing property, includes briquetting (1), briquetting (2) down, left side wedge-shaped latch segment (4), right side wedge-shaped latch segment, left side fastening bolt, right side fastening bolt (8), V-arrangement breach roof beam sample (9), goes up clamping bolt (10), centre gripping bolt (11) down, goes up centering device (12), centering device (13) down, goes up guide rail post (14), guide rail post (16) down, goes up load bar (15) and load bar (17) down. The clamp is simple and convenient to assemble and disassemble the V-shaped notched beam samples through the left and right rectangular holes (205), is suitable for V-shaped notched beam samples with different sizes in a combined clamping mode through the left and right wedge-shaped locking blocks and the upper and lower rectangular gaskets, and has strong adjustability.

Description

Clamp for testing shearing performance of composite material

Technical Field

The utility model relates to a clamp for testing the shearing performance of a composite material, belonging to the technical field of composite material performance testing.

Background

At present, for the experimental study of the shearing performance of the composite material, an orbit shearing method (including a double-orbit shearing method and a three-orbit shearing method), an Iosipescu shearing method, a V-shaped notch orbit shearing method and the like are mainly adopted. The Iosipescu shearing method is widely applied to the field of shearing performance testing of composite materials and is formulated into a test standard ASTM D5379 because the test method is simple and easy to operate and implement, the required V-shaped notched beam sample is easy to process, and the obtained test result of the sample is ideal. The test standard describes a clamp special for testing the shearing performance of a composite material V-shaped notched beam sample, loads are applied to the V-shaped notched beam sample through relative displacement between two parts of the clamp, the vertical central line of a V-shaped notch of the V-shaped notched beam sample is consistent with a load action line through a centering tool, and through the matching between a bearing rod and a clamping block containing a linear bearing, the V-shaped notched beam sample can only move along the load action line direction, the influence generated by bending deformation of the sample is reduced, and a uniform shearing stress field is formed near the V-shaped notch. However, the clamp still has certain disadvantages, in particular as follows:

(1) the V-shaped notched beam test sample is difficult to position along the thickness direction, namely the direction of a loading central line is not consistent with the vertical central line of the V-shaped notch aiming at the test samples with different thicknesses, so that the experimental result is seriously influenced;

(2) when the thickness of a test sample for testing the V-shaped notched beam is thinner, the test difficulty is greatly improved, so that reinforcing sheets are required to be locally adhered to two surfaces of the test sample far away from a test section so as to improve the stability of the test sample, but the workload during test preparation is greatly increased;

(3) when the applied load is large, the clamp is bent and deformed, so that the stress state of the V-shaped notched beam sample is changed, a complex stress state with bending and shearing acting simultaneously is presented, the friction force between the chuck and the bearing rod is further increased, and the test result is seriously influenced.

In view of the above disadvantages, the related art has developed an improvement, such as that disclosed in CN207066861U, which discloses a fixture for shear performance test of V-notch beam specimens. The clamping apparatus improves the situation that samples with different thicknesses are difficult to position along the thickness direction, reduces the probability of unnecessary bending load generated when the V-shaped notched beam sample bears the load, reduces the friction force between the supporting column and the clamping block, and improves the accuracy of the shear performance test data of the sample. However, the clamp is complex in structural form, complex in the process of assembling and disassembling a V-shaped notched beam sample, large in positioning error along the thickness direction of the sample, and not easy to observe the condition of the sample installed in the clamp in the test process, so that the clamp has great limitation.

Then, a related technician designs a novel clamp for testing the shearing performance of a V-shaped notched beam sample, such as the publication No. CN112798406A, and discloses a clamp for testing the shearing performance of a composite material. The fixture is suitable for various V-shaped slotted samples with different sizes, strong in adjustability, far away from the test section at the clamping end, capable of reducing the probability of stress concentration phenomenon and effectively reducing unnecessary friction and bending load borne by the V-shaped slotted samples under large load. However, the clamp is complex in structural form, tedious in process of dismounting the V-shaped slotted sample, difficult to position and center along the thickness direction of the V-shaped slotted sample, and has great limitation.

Disclosure of Invention

The utility model aims to solve the problems that the existing clamp is difficult to accurately position and center along the thickness direction of a V-shaped notched beam sample in the using process, the sample is complex to assemble and disassemble, and the clamp is subjected to bending deformation due to large load, so that the sample is bent and sheared simultaneously and is in a complex stress state, and provides the clamp for testing the shearing performance of a composite material.

According to the technical scheme, the clamp for testing the shearing performance of the composite material comprises an upper pressing block 1, a lower pressing block 2, an upper rectangular cushion block 3, a left wedge-shaped locking block 4, a left fastening bolt 5, a lower rectangular cushion block 6, a right wedge-shaped locking block 7, a right fastening bolt 8, a V-shaped notched beam sample 9, an upper clamping bolt 10, a lower clamping bolt 11, an upper centering device 12, a lower centering device 13, an upper guide rail column 14, a lower guide rail column 16, an upper loading rod 15 and a lower loading rod 17.

The upper pressing block 1 comprises an upper loading rod bolt hole 101, an upper linear bearing hole 102, an upper T-shaped centering groove 103, an upper trapezoidal groove 104, a left rectangular hole 105, a left unthreaded hole 106, an upper clamping bolt hole 107 and an upper guide rail column hole 108; the lower press block 2 comprises a lower loading rod bolt hole 201, a lower linear bearing hole 202, a lower T-shaped centering groove 203, a lower trapezoidal groove 204, a right rectangular hole 205, a right smooth hole 206, a lower clamping bolt hole 207 and a lower guide rail column hole 208.

The upper pressing block and the lower pressing block are both of L-shaped structures, the long side of each L-shaped structure is a square long column, the short side of each L-shaped structure is a square short column, and the square long columns are perpendicular to the square short columns; an upper dovetail groove is formed in the square long column of the upper pressing block, the left wedge-shaped locking block is installed in the upper dovetail groove, upper clamping bolt holes are formed in two sides of the upper dovetail groove, upper clamping bolts are installed, and an upper rectangular cushion block is fixed; the end part of the square long column of the upper pressing block is provided with an upper guide rail column hole, and the upper guide rail column is arranged in the upper guide rail column hole; an upper loading rod bolt hole and an upper linear bearing hole are formed in the horizontal plane of the square short column of the upper pressing block, and the upper loading rod is installed in the upper loading rod bolt hole; a lower trapezoidal groove is formed in the square long column of the lower pressing block, the right wedge-shaped locking block is installed in the lower trapezoidal groove, lower clamping bolt holes are formed in two sides of the lower trapezoidal groove, lower clamping bolts are installed, and a lower rectangular cushion block is fixed; the end part of the square long column of the lower pressing block is provided with a lower guide rail column hole, and the lower guide rail column is arranged in the lower guide rail column hole; a lower loading rod bolt hole and a lower linear bearing hole are formed in the horizontal plane of the square short column of the lower pressing block, and the lower loading rod is installed in the lower loading rod bolt hole; the other end of the upper guide rail column is inserted into a lower linear bearing hole of the square short column of the lower pressing block; the other end of the lower guide rail column is inserted into an upper linear bearing hole of the square short column of the upper pressing block; a T-shaped centering groove is formed in the square short cylindrical surface of the junction of the square short column and the square long column of the upper pressing block, and the T-shaped end of the upper centering device is installed in the T-shaped centering groove; a T-shaped centering groove is formed in the square short cylindrical surface of the junction of the square short column and the square long column of the lower pressing block, and the T-shaped end of the lower centering device is installed in the T-shaped centering groove; the V-shaped notched beam sample is positioned between the upper centering device and the lower centering device; the two upper rectangular cushion blocks are respectively arranged between the front side surface of the left end of the V-shaped notched beam sample and the front side surface of the upper trapezoidal groove as well as between the rear side surface of the left end of the V-shaped notched beam sample and the rear side surface of the upper trapezoidal groove; the lower rectangular cushion blocks are respectively arranged between the front side surface of the right end of the V-shaped notched beam sample and the front side surface of the lower trapezoidal groove, and between the rear side surface of the right end of the V-shaped notched beam sample and the rear side surface of the lower trapezoidal groove; a left rectangular hole and a left unthreaded hole are formed in the side face of the square long column of the upper pressing block, the left unthreaded hole is communicated with the upper trapezoidal groove, and a left fastening bolt enters from the left unthreaded hole and is connected with the left wedge-shaped locking block; the side face of the square long column of the lower pressing block is provided with a right rectangular hole and a right unthreaded hole, the right unthreaded hole is communicated with the lower trapezoidal groove, and a right fastening bolt enters from the right unthreaded hole and is connected with the right wedge-shaped locking block.

The upper centering device comprises an upper T-shaped centering block, an upper centering positioning fastening bolt and an upper centering positioning hole; the upper centering device is of a T-shaped structure and is vertically connected with the strip-shaped plate through a strip-shaped plate, and one end of the upper centering device is a T-shaped end; the end part of the other end is wedge-shaped, and a rectangular upper centering positioning hole is formed in the plate above the wedge-shaped end; the upper rectangular block of the upper centering positioning block is inserted into the rectangular hole and is fixed by an upper centering positioning fastening bolt; the lower centering device comprises a lower T-shaped centering block, a lower centering positioning fastening bolt and a lower centering positioning hole; the lower centering device is of a T-shaped structure and is vertically connected with the elongated plate through a rectangular plate, and one end of the lower centering device is a T-shaped end; the end part of the other end is wedge-shaped, and a rectangular lower centering positioning hole is formed in the plate above the wedge-shaped end; and the lower rectangular block of the lower centering positioning block is inserted into the rectangular hole and is fixed by a lower centering positioning fastening bolt.

The upper centering device 12 and the lower centering device 13 adjust centering by co-action; the upper T-shaped centering block 12 can only slide on the upper T-shaped centering groove 103 along the thickness direction of the V-shaped notched beam sample 9, and the vertical center line of the upper T-shaped centering groove 103 is overlapped with the vertical center line of the upper loading rod 15; the other end of the upper T-shaped centering block 121 is aligned with the V-shaped notch of the V-shaped notch beam sample 9; the upper centering positioning block 122 is matched with the upper centering positioning hole 1211 on the upper T-shaped centering block 121, and the upper centering positioning block 122 can only slide on the upper centering positioning hole 1211 along the thickness direction of the V-shaped notched beam sample 9; the upper centering fastening bolt 123 is used for fixing the position of the upper centering positioning block 122;

the T-shaped end of the lower T-shaped centering block 131 is matched with the lower T-shaped centering groove 203 on the lower pressing block 2, the lower T-shaped centering block 131 can only slide in the lower T-shaped centering groove 203 along the thickness direction of the V-shaped notched beam sample 9, the vertical center line of the lower T-shaped centering groove 203 is coincided with the vertical center line of the lower loading rod 17, and the other end of the lower T-shaped centering block 131 is aligned with the V-shaped notch of the V-shaped notched beam sample 9; the lower centering positioning block 132 is matched with the lower centering positioning hole 1311 on the lower T-shaped centering block 131, and the lower centering positioning block 132 can only slide in the lower centering positioning hole 1311 along the thickness direction of the V-shaped notched beam sample 9; the lower centering fastening bolt 133 is used to fix the position of the lower centering positioning block 132.

The T-shaped end of the upper T-shaped centering block 121 is matched with the upper T-shaped centering groove 103, the other end of the upper T-shaped centering block 121 is provided with scales along the thickness direction of the V-shaped notched beam sample 9, and the vertical center line of the V-shaped notched beam sample 9 is coincided with the vertical center line of the upper loading rod 15 by matching with the upper centering positioning block 122;

the T-shaped end of the lower T-shaped centering block 131 is matched with the lower T-shaped centering groove 203, the other end of the lower T-shaped centering block 131 is provided with scales along the thickness direction of the V-shaped notched beam sample 9, and the vertical center line of the V-shaped notched beam sample 9 is coincided with the vertical center line of the lower loading rod 17 through matching with the lower centering positioning block 132.

The upper clamping bolt is in threaded connection with the upper clamping bolt hole, and the upper rectangular cushion block is extruded by screwing the upper clamping bolt, so that the left end of the V-shaped notched beam sample is clamped tightly by the upper rectangular cushion block; the lower clamping bolt is in threaded connection with the lower clamping bolt hole, and the lower rectangular cushion block is extruded by screwing down the lower clamping bolt, so that the right end of the V-shaped notched beam sample is clamped tightly by the lower rectangular cushion block.

The left wedge-shaped locking block 4 is arranged between the upper inclined plane of the upper trapezoidal groove 104 and the left end of the V-shaped notched beam sample 9, and a threaded hole penetrating through the left wedge-shaped locking block 4 is formed; the right wedge-shaped locking block 7 is arranged between the lower inclined plane of the lower trapezoidal groove 204 and the right end of the V-shaped notched beam sample 9, and the right wedge-shaped locking block 7 is provided with a through threaded hole.

The left fastening bolt 5 penetrates through the left unthreaded hole 106 to be in threaded connection with the left wedge-shaped locking block 4, and the left fastening bolt 5 is screwed to drive the left wedge-shaped locking block 4 to wedge the left end of the V-shaped notched beam sample 9; the right side fastening bolt 8 penetrates through the right side unthreaded hole 206 and is in threaded connection with the right side wedge-shaped locking block 7, and the right side fastening bolt 8 is screwed down to drive the right side wedge-shaped locking block 7 to wedge the right end of the V-shaped notched beam sample 9.

The upper loading rod 15 is provided with an upper loading rod radial round hole 151, and the upper loading rod radial round hole 151 is used for being connected with a testing machine; the upper loading rod 15 is in threaded connection with the upper loading rod bolt hole 101 on the upper pressing block 1; the lower loading rod 17 is provided with a lower loading rod radial round hole 171, and the lower loading rod radial round hole 171 is used for being connected with a testing machine; the lower loading rod 17 is in threaded connection with the lower loading rod bolt hole 201 on the lower pressing block 2.

The left fastening bolt 5 comprises a polished rod section and a threaded section, the left wedge-shaped locking block 4 is provided with a left wedge-shaped locking block threaded hole 41 which penetrates through the left wedge-shaped locking block, and the left fastening bolt 5 is connected with the left polished hole 106 through the polished rod section and is in threaded connection with the left wedge-shaped locking block threaded hole 41 in the left wedge-shaped locking block 4 through the threaded section;

right side fastening bolt 8 includes polished rod section and screw thread section, right side wedge-shaped locking piece 7 has right side wedge-shaped locking piece screw hole 71 that runs through, right side fastening bolt 8 pass through the polished rod section with right side unthreaded hole 206 is connected, through the screw thread section with right side wedge-shaped locking piece screw hole 71 threaded connection on the right side wedge-shaped locking piece 7.

The inclined angles of the axis of the left unthreaded hole 106 on the upper pressing block 1, the upper inclined plane of the upper trapezoidal groove 104, the axis of the threaded hole 41 of the left wedge-shaped locking block and the upper inclined plane of the left wedge-shaped locking block 4 are the same;

the inclined angles of the axis of the right light hole 206 on the lower pressing block 2, the lower inclined plane of the lower trapezoidal groove 204, the axis of the threaded hole 71 of the right wedge-shaped locking block and the lower inclined plane of the right wedge-shaped locking block 7 are the same.

The V-shaped notched beam test fixture has the beneficial effects that the V-shaped notched beam test fixture is simple and convenient to assemble and disassemble through the left and right rectangular holes, is suitable for V-shaped notched beam test samples with different sizes in a combined clamping mode of the left and right wedge-shaped locking blocks and the upper and lower rectangular gaskets, has strong adjustability, has a clamping end far away from a shearing area, can avoid the phenomenon of stress concentration, can effectively reduce unnecessary friction force and bending moment borne by the V-shaped notched beam test sample under a large load, and can ensure that the vertical center line of the V-shaped notch of the V-shaped notched test sample is consistent with the loading center line by adjusting the positions of the upper and lower centering positioning blocks with scales of the upper and lower T-shaped centering blocks according to the thickness of the V-shaped notched beam test sample, so that the positioning and centering problems of the test samples with different thicknesses are solved.

Drawings

FIG. 1 is a schematic overall structure diagram of an embodiment of the present invention;

FIG. 2 is another schematic view of the overall structure of the embodiment of the present invention;

FIG. 3 is a disassembled view of the whole structure of the embodiment of the present invention;

FIG. 4 is a schematic diagram of a structure of an upper pressing block according to an embodiment of the present invention;

FIG. 5 is a schematic view of a hold-down block structure according to an embodiment of the present invention;

FIG. 6 is a schematic view of a wedge-shaped locking block and a fastening bolt according to an embodiment of the present invention;

FIG. 7 is a schematic diagram of a spacer structure according to an embodiment of the present invention;

FIG. 8 is a schematic structural diagram of a centering device according to an embodiment of the present invention;

FIG. 9 is a disassembled view of the centering device according to the embodiment of the present invention;

FIG. 10 is a schematic view of a load lever according to an embodiment of the present invention;

in the figure, 1 is an upper briquetting; 101 is an upper loading rod bolt hole; 102 is an upper linear bearing hole; 103 is an upper T-shaped centering groove; 104 is an upper trapezoidal groove; 105 is a left rectangular hole; 106 is a left light hole; 107 is an upper clamping bolt hole; 108 is an upper guide rail column hole; 2, pressing the block; 201 is a lower load bar bolt hole; 202 is a lower linear bearing hole; 203 is a lower T-shaped centering slot; 204 is a lower trapezoidal groove; 205 is a right rectangular hole; 206 is a right side aperture; 207 is a lower clamping bolt hole; 208 is a lower guide rail column hole; 3 is an upper rectangular cushion block; 4 is a left wedge-shaped locking block; 41 is a threaded hole of the left wedge-shaped locking block; 5 is a left fastening bolt; 6 is a lower rectangular cushion block; 7 is a right wedge-shaped locking block; 71 is a threaded hole of the right wedge-shaped locking block; 8 is a right fastening bolt; 9 is a V-shaped notched beam sample; 10 is an upper clamping bolt; 11 is a lower clamping bolt; 12 is an upper centering device; 121 is an upper T-shaped centering block; 1211 is an upper centering hole; 122 is an upper centering positioning block; 123 is an upper centering positioning fastening bolt; 13 is a lower centering device; 131 is a lower T-shaped centering block; 1311 is a lower centering hole; 132 is a lower centering positioning block; 133 is a lower centering fastening bolt; 14 is an upper guide rail column; 15 is an upper loading rod; 151 is an upper loading rod radial round hole; 16 is a lower guide rail column; 17 is a lower loading rod; 171 is a lower load bar radial bore.

Detailed Description

In order to make the implementation objects, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present application will be clearly and more thoroughly described below with reference to the drawings in the embodiments of the present application.

The present invention will be described in further detail with reference to fig. 1 to 10.

The embodiment provides a clamp for testing the shearing performance of a composite material, which comprises an upper pressing block 1, a lower pressing block 2, an upper rectangular cushion block 3, a lower rectangular cushion block 6, a left wedge-shaped locking block 4, a right wedge-shaped locking block 7, a V-shaped notched beam sample 9, a left fastening bolt 5, a right fastening bolt 8, an upper clamping bolt 10, a lower clamping bolt 11, an upper centering device 12, a lower centering device 13, an upper guide rail column 14, a lower guide rail column 16, an upper loading rod 15 and a lower loading rod 17.

Specifically, as shown in fig. 3 and 4, the upper pressing block 1 includes: upper load bar bolt holes 101, upper linear bearing holes 102, upper T-shaped centering slots 103, upper trapezoidal slots 104, left rectangular holes 105, left unthreaded holes 106, upper clamp bolt holes 107, and upper guide rail post holes 108.

As shown in fig. 3 and 5, the lower pressing block 2 includes: a lower loading rod bolt hole 201, a lower linear bearing hole 202, a lower T-shaped centering groove 203, a lower trapezoidal groove 204, a right rectangular hole 205, a right smooth hole 206, a lower clamping bolt hole 207 and a lower guide rail column hole 208.

A left rectangular hole 105 and a left unthreaded hole 106 are formed in the bottom of the upper trapezoidal groove 104, upper clamping bolt holes 107 are formed in the front side surface and the rear side surface of the upper trapezoidal groove 104, the left rectangular hole 105 is used for mounting the V-shaped notched beam sample 9, and the size of the V-shaped notched beam sample 9 is matched with the size of the left rectangular hole 105; the left light hole 106 is parallel to the upper slope of the upper trapezoidal groove 104.

A right rectangular hole 205 and a right unthreaded hole 206 are formed in the bottom of the lower trapezoidal groove 204, lower clamping bolt holes 207 are formed in the front and rear side surfaces of the lower trapezoidal groove 204, the right rectangular hole 205 is used for mounting the V-shaped notched beam sample 9, and the size of the V-shaped notched beam sample 9 is matched with the size of the right rectangular hole 205; the right light hole 206 is parallel to the lower inclined surface of the lower trapezoidal groove 204.

As shown in FIG. 10, one end of the upper loading rod 15 is provided with a pin hole for connecting with one end of the testing machine, and the threaded end is in threaded connection with the upper loading rod bolt hole 101.

As shown in fig. 10, one end of the lower loading rod 17 is provided with a pin hole for connecting with one end of the testing machine, and the threaded end is in threaded connection with the lower loading rod bolt hole 201.

The upper guide rail column 14 is embedded in the upper guide rail column hole 108 on the upper press block 1 and is in sliding fit with the lower linear bearing hole 202. The lower guide rail column 16 is embedded in the lower guide rail column hole 208 on the lower press block 2 and is in sliding fit with the upper linear bearing hole 102. The upper pressing block 1 and the lower pressing block 2 are connected to form the main body of the clamp for testing the shearing performance of the composite material as shown in fig. 1 and 2.

Wherein, two ends of the V-shaped notched beam sample 9 are respectively arranged in the corresponding upper trapezoidal groove 104 and the lower trapezoidal groove 204; the left wedge-shaped locking block 4 is placed between the upper inclined plane of the upper trapezoidal groove 104 and the left end of the V-shaped notched beam sample 9, the left wedge-shaped locking block 4 is provided with a left wedge-shaped locking block threaded hole 41 which penetrates through the left wedge-shaped locking block 4 and is parallel to the upper inclined surface of the upper trapezoidal groove 104, as shown in fig. 6, the left fastening bolt 5 comprises a polished rod section and a threaded section, the left fastening bolt 5 is connected with the left polished hole 106 through the polished rod section and is in threaded connection with the left wedge-shaped locking block threaded hole 41 on the left wedge-shaped locking block 4 through the threaded section; the left-side fastening bolt 5 is screwed to drive the left-side wedge-shaped locking block 4 to move along the upper inclined surface of the upper trapezoidal groove 104, so that the end support of the V-shaped notched beam sample 9 is provided; the axial line of the left unthreaded hole 106, the upper inclined plane of the upper trapezoidal groove 104 and the axial line of the left wedge-shaped locking block threaded hole 41 have the same inclination angles with the upper inclined plane of the left wedge-shaped locking block 4; the two upper rectangular cushion blocks 3 are respectively arranged between the front side surface of the left end of the V-shaped notched beam sample 9, the front side surface of the upper trapezoidal groove 104, and the rear side surface of the left end of the V-shaped notched beam sample and the rear side surface of the upper trapezoidal groove 104; the upper clamping bolt 10 is in threaded connection with the upper clamping bolt hole 107, and the upper rectangular cushion block 3 is extruded by screwing the upper clamping bolt 10, so that the left end of the V-shaped notched beam sample 9 is clamped tightly by the upper rectangular cushion block 3.

The right wedge-shaped locking block 7 is arranged between the lower inclined surface of the lower trapezoidal groove 204 and the right end of the V-shaped notched beam sample 9, the right wedge-shaped locking block 7 is provided with a right wedge-shaped locking block threaded hole 71 which penetrates through the right wedge-shaped locking block 7 and is parallel to the lower inclined surface of the lower trapezoidal groove 204, the right fastening bolt 8 comprises a polished rod section and a threaded section, the right fastening bolt 8 is connected with the right smooth hole 206 through the polished rod section and is in threaded connection with the right wedge-shaped locking block threaded hole 71 in the right wedge-shaped locking block 7 through the threaded section; the right side fastening bolt 8 is screwed to drive the right side wedge-shaped locking block 7 to move along the lower side inclined surface of the lower trapezoidal groove 204, so that the end part of the V-shaped notched beam sample 9 is supported; the axial line of the right light hole 206 on the lower pressing block 2, the lower inclined plane of the lower trapezoidal groove 204, the lower inclined plane of the right wedge-shaped locking block 7 and the axial line of the threaded hole 71 of the right wedge-shaped locking block are parallel; the two lower rectangular cushion blocks are respectively arranged between the front side surface of the right end of the V-shaped notched beam sample 9 and the front side surface of the lower trapezoidal groove 204, and between the rear side surface of the right end of the V-shaped notched beam sample and the rear side surface of the lower trapezoidal groove 204; the lower clamping bolt 11 is in threaded connection with the lower clamping bolt hole 207, and the lower rectangular cushion block 6 is extruded by screwing the lower clamping bolt 11, so that the right end of the V-shaped notched beam sample 9 is clamped tightly by the lower rectangular cushion block 6.

The upper centering device 12 is shown in figures 3, 8 and 9

The upper centering device 12 includes: an upper T-shaped centering block 121, an upper centering positioning block 122 and an upper centering positioning fastening bolt 123. The T-shaped end of the upper T-shaped centering block 121 is fitted with the upper T-shaped centering groove 103 of the upper press block 1, the upper T-shaped centering block 12 can only slide in the upper T-shaped centering groove 103 along the thickness direction of the V-shaped notched beam sample 9, the vertical center line of the upper T-shaped centering groove 103 coincides with the vertical center line of the upper loading rod 15, one end of the upper T-shaped centering block 121 is aligned with the V-shaped notch of the V-shaped notched beam sample 9, and an upper centering positioning hole 1211 is formed. The upper centering and positioning block 122 is fitted to the upper centering and positioning hole 1211, and the upper centering and positioning block 122 can only slide in the upper centering and positioning hole 1211 along the thickness direction of the V-shaped notched beam sample 9. The upper centering fastening bolt 123 is used for fixing the position of the upper centering positioning block 122. Meanwhile, one end of the upper T-shaped centering block 121 is provided with scales along the thickness direction of the V-shaped notched beam sample 9, the position of the upper centering positioning block 122 is adjusted and fixed by measuring the thickness of the V-shaped notched beam sample before testing, so that the vertical center line of the V-shaped notched beam sample 9 coincides with the vertical center line of the upper loading rod 15, and centering in the thickness direction is realized.

The lower centering device 13 includes: a lower T-shaped centering block 131, a lower centering positioning block 132 and a lower centering fastening bolt 133. The T-shaped end of the lower T-shaped centering block 131 is matched with the lower T-shaped centering groove 203 on the lower pressing block 2, the lower T-shaped centering block 131 can only slide in the lower T-shaped centering groove 203 along the thickness direction of the V-shaped notched beam sample 9, the vertical center line of the lower T-shaped centering groove 203 is overlapped with the vertical center line of the lower loading rod 17, the other end of the lower T-shaped centering block 13 is aligned with the V-shaped notch of the V-shaped notched beam sample 9, and a lower centering positioning hole 1311 is formed. The lower centering and positioning block 132 is adapted to the lower centering and positioning hole 1311, and the lower centering and positioning block 132 can only slide in the lower centering and positioning hole 1311 along the thickness direction of the V-shaped notched beam specimen 9. The lower centering fastening bolt 133 is used to fix the position of the lower centering positioning block 132. Meanwhile, one end of the lower T-shaped centering block 131 is provided with scales along the thickness direction of the V-shaped notched beam sample 9, the position of the lower centering positioning block 132 is adjusted and fixed by measuring the thickness of the V-shaped notched beam sample before testing, so that the vertical center line of the V-shaped notched beam sample 9 coincides with the vertical center line of the lower loading rod 17, and centering in the thickness direction is realized.

In conclusion, the problem that the V-shaped notched beam sample is difficult to disassemble and assemble is solved through the left and right rectangular holes of the clamp; the problem of complicated centering along the thickness direction of the V-shaped notched beam sample is solved through the T-shaped centering block with scales and the centering positioning block; the thickness of the cushion block is adjusted to be adaptive to samples with different sizes, so that the application range is wide; the upper pressing block and the lower pressing block of the clamp are connected through the guide rail columns, so that the stability is improved, meanwhile, unnecessary friction and bending load borne by the V-shaped slotted test sample are effectively reduced, and the reliability of the test is enhanced.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present application should be covered within the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims (10)

1. A clamp for testing the shearing performance of a composite material is characterized by comprising an upper pressing block, a lower pressing block, an upper rectangular cushion block, a lower rectangular cushion block, a left wedge-shaped locking block, a right wedge-shaped locking block, a left fastening bolt, a right fastening bolt, a V-shaped notched beam sample, an upper clamping bolt, a lower clamping bolt, an upper centering device, a lower centering device, an upper guide rail column, a lower guide rail column, an upper loading rod and a lower loading rod;

the upper pressing block comprises an upper loading rod bolt hole, an upper linear bearing hole, an upper T-shaped centering groove, an upper trapezoidal groove, a left rectangular hole, a left unthreaded hole, an upper clamping bolt hole and an upper guide rail column hole; the lower pressing block comprises a lower loading rod bolt hole, a lower linear bearing hole, a lower T-shaped centering groove, a lower trapezoidal groove, a right rectangular hole, a right unthreaded hole, a lower clamping bolt hole and a lower guide rail column hole;

the upper pressing block and the lower pressing block are both of L-shaped structures, the long side of each L-shaped structure is a square long column, the short side of each L-shaped structure is a square short column, and the square long columns are perpendicular to the square short columns; an upper dovetail groove is formed in the square long column of the upper pressing block, the left wedge-shaped locking block is installed in the upper dovetail groove, upper clamping bolt holes are formed in two sides of the upper dovetail groove, upper clamping bolts are installed, and an upper rectangular cushion block is fixed; the end part of the square long column of the upper pressing block is provided with an upper guide rail column hole, and the upper guide rail column is arranged in the upper guide rail column hole; an upper loading rod bolt hole and an upper linear bearing hole are formed in the horizontal plane of the square short column of the upper pressing block, and the upper loading rod is installed in the upper loading rod bolt hole; a lower trapezoidal groove is formed in the square long column of the lower pressing block, the right wedge-shaped locking block is installed in the lower trapezoidal groove, lower clamping bolt holes are formed in two sides of the lower trapezoidal groove, lower clamping bolts are installed, and a lower rectangular cushion block is fixed; the end part of the square long column of the lower pressing block is provided with a lower guide rail column hole, and the lower guide rail column is arranged in the lower guide rail column hole; a lower loading rod bolt hole and a lower linear bearing hole are formed in the horizontal plane of the square short column of the lower pressing block, and the lower loading rod is installed in the lower loading rod bolt hole; the other end of the upper guide rail column is inserted into a lower linear bearing hole of the square short column of the lower pressing block; the other end of the lower guide rail column is inserted into an upper linear bearing hole of the square short column of the upper pressing block; an upper T-shaped centering groove is formed in the square short cylindrical surface of the junction of the square short column and the square long column of the upper pressing block, and the T-shaped end of the upper centering device is installed in the upper T-shaped centering groove; a lower T-shaped centering groove is formed in the square short cylindrical surface of the junction of the square short column and the square long column of the lower pressing block, and the T-shaped end of the lower centering device is installed in the lower T-shaped centering groove; the V-shaped notched beam sample is positioned between the upper centering device and the lower centering device; the two upper rectangular cushion blocks are respectively arranged between the front side surface of the left end of the V-shaped notched beam sample and the front side surface of the upper trapezoidal groove as well as between the rear side surface of the left end of the V-shaped notched beam sample and the rear side surface of the upper trapezoidal groove; the lower rectangular cushion blocks are respectively arranged between the front side surface of the right end of the V-shaped notched beam sample and the front side surface of the lower trapezoidal groove, and between the rear side surface of the right end of the V-shaped notched beam sample and the rear side surface of the lower trapezoidal groove; a left rectangular hole and a left unthreaded hole are formed in the side face of the square long column of the upper pressing block, the left unthreaded hole is communicated with the upper trapezoidal groove, and a left fastening bolt enters and is connected with the left wedge-shaped locking block from the left unthreaded hole; the square long column side of the lower pressing block is provided with a right rectangular hole and a right unthreaded hole, the right unthreaded hole is communicated with the lower trapezoidal groove, and a right fastening bolt enters and is connected with the right wedge-shaped locking block through the right unthreaded hole.

2. The clamp for testing the shearing performance of the composite material as claimed in claim 1, wherein the upper centering device comprises an upper T-shaped centering block, an upper centering positioning fastening bolt and an upper centering positioning hole; the upper centering device is of a T-shaped structure and is vertically connected with the strip-shaped plate through a strip-shaped plate, and one end of the upper centering device is a T-shaped end; the end part of the other end is wedge-shaped, and a rectangular upper centering positioning hole is formed in the plate above the wedge-shaped end; the upper rectangular block of the upper centering positioning block is inserted into the rectangular hole and is fixed by an upper centering positioning fastening bolt; the lower centering device comprises a lower T-shaped centering block, a lower centering positioning fastening bolt and a lower centering positioning hole; the lower centering device is of a T-shaped structure and is vertically connected with the elongated plate through a rectangular plate, and one end of the lower centering device is a T-shaped end; the end part of the other end is wedge-shaped, and a rectangular lower centering positioning hole is formed in the plate above the wedge-shaped end; the lower rectangular block of the lower centering positioning block is inserted into the rectangular hole and fixed by a lower centering positioning fastening bolt.

3. The clamp for testing the shearing performance of the composite material as claimed in claim 1, wherein the upper clamping bolt is in threaded connection with the upper clamping bolt hole, and the upper rectangular cushion block is squeezed by tightening the upper clamping bolt, so that the left end of the V-shaped notched beam sample is clamped by the upper rectangular cushion block; the lower clamping bolt is in threaded connection with the lower clamping bolt hole, and the lower rectangular cushion block is extruded by screwing down the lower clamping bolt, so that the right end of the V-shaped notched beam sample is clamped tightly by the lower rectangular cushion block.

4. The clamp for testing the shearing performance of the composite material as claimed in claim 1, wherein the left wedge-shaped locking block is placed between the upper inclined plane of the upper dovetail groove and the left end of the V-shaped notched beam sample, and is provided with a through threaded hole; the right side wedge-shaped locking block is arranged between the lower side inclined plane of the lower trapezoidal groove and the right end of the V-shaped notched beam sample, and a penetrating threaded hole is formed in the right side wedge-shaped locking block.

5. The clamp for testing the shearing performance of the composite material as claimed in claim 1, wherein the left fastening bolt passes through the left unthreaded hole to be in threaded connection with the left wedge-shaped locking block, and the left fastening bolt is tightened to drive the left wedge-shaped locking block to wedge the left end of the V-shaped notched beam sample; and the right fastening bolt penetrates through the right unthreaded hole to be in threaded connection with the right wedge-shaped locking block, and the right fastening bolt is screwed down to drive the right wedge-shaped locking block to wedge the right end of the V-shaped notched beam sample.

6. The clamp for testing the shearing performance of the composite material as claimed in claim 1, wherein the upper loading rod is provided with an upper loading rod radial round hole, and the upper loading rod radial round hole is used for being connected with a testing machine; the upper loading rod is in threaded connection with the upper loading rod bolt hole on the upper pressing block; the lower loading rod is provided with a lower loading rod radial round hole which is used for being connected with the testing machine; the lower loading rod is in threaded connection with the lower loading rod bolt hole in the lower pressing block.

7. The clamp for testing the shearing performance of the composite material as claimed in claim 1, wherein the left fastening bolt comprises a polished rod section and a threaded section, the left wedge-shaped locking block is provided with a left wedge-shaped locking block threaded hole which penetrates through the polished rod section, the left fastening bolt is connected with the left polished hole through the polished rod section and is in threaded connection with the left wedge-shaped locking block threaded hole on the left wedge-shaped locking block through the threaded section;

the right side fastening bolt comprises a polished rod section and a thread section, the right side wedge-shaped locking block is provided with a right side wedge-shaped locking block thread hole which penetrates through the right side wedge-shaped locking block, and the right side fastening bolt is connected with the right side polished hole through the polished rod section and is in threaded connection with the right side wedge-shaped locking block thread hole in the right side wedge-shaped locking block through the thread section.

8. The clamp for testing the shearing performance of the composite material as claimed in claim 7, wherein the axis of the left unthreaded hole on the upper pressing block, the upper inclined plane of the upper trapezoidal groove, the axis of the threaded hole of the left wedge locking block and the upper inclined plane of the left wedge locking block have the same inclination angle;

the inclined angle of the axis of the right side unthreaded hole on the lower pressing block, the lower side inclined plane of the lower trapezoidal groove, the axis of the threaded hole of the right side wedge-shaped locking block and the lower side inclined plane of the right side wedge-shaped locking block is the same.

9. The jig for testing shear performance of composite materials of claim 2, wherein the upper centering device and the lower centering device cooperate to adjust the centering; the upper T-shaped centering block can only slide in the upper T-shaped centering groove along the thickness direction of the V-shaped notched beam sample, and the vertical center line of the upper T-shaped centering groove is coincided with the vertical center line of the upper loading rod; the other end of the upper T-shaped centering block is aligned with the V-shaped notch of the V-shaped notch beam sample; the upper centering positioning block is matched with the upper centering positioning hole in the upper T-shaped centering block, and the upper centering positioning block can only slide in the upper centering positioning hole along the thickness direction of the V-shaped notched beam sample; the upper centering positioning fastening bolt is used for fixing the position of the upper centering positioning block;

the T-shaped end of the lower T-shaped centering block is matched with the lower T-shaped centering groove on the lower pressure block, the lower T-shaped centering block can only slide in the lower T-shaped centering groove along the thickness direction of the V-shaped notched beam sample, the vertical center line of the lower T-shaped centering groove is coincided with the vertical center line of the lower loading rod, and the other end of the lower T-shaped centering block is aligned with the V-shaped notch of the V-shaped notched beam sample; the lower centering positioning block is matched with the lower centering positioning hole in the lower T-shaped centering block, and the lower centering positioning block can only slide in the lower centering positioning hole along the thickness direction of the V-shaped notched beam sample; the lower centering and positioning fastening bolt is used for fixing the position of the lower centering and positioning block.

10. The clamp for testing the shearing performance of the composite material as claimed in claim 9, wherein a T-shaped end of the upper T-shaped centering block is matched with the upper T-shaped centering groove, and the other end of the upper T-shaped centering block is provided with a scale along the thickness direction of the V-shaped notched beam sample, so that the vertical center line of the V-shaped notched beam sample coincides with the vertical center line of the upper loading rod by matching with the upper centering positioning block;

the T-shaped end of the lower T-shaped centering block is matched with the lower T-shaped centering groove, the other end of the lower T-shaped centering block is provided with scales along the thickness direction of the V-shaped notched beam sample, and the vertical center line of the V-shaped notched beam sample is coincided with the vertical center line of the lower loading rod through matching with the lower centering positioning block.

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