CN-121994585-A - Bonding centering device for rock direct tensile test and operation method

CN121994585ACN 121994585 ACN121994585 ACN 121994585ACN-121994585-A

Abstract

The invention discloses an adhesive centering device and an operation method for a rock direct tensile test, wherein the device comprises a clamp plate main body, a centering clamp holder and a centering clamp holder, wherein the clamp plate main body comprises a clamp plate pressure head and a clamp plate base, the clamp plate pressure head and the clamp plate base are connected through a connecting rod and coaxially arranged, the centering clamp holder is arranged between the clamp plate pressure head and the clamp plate base and is used for clamping and centering a rock sample before adhesion, the centering clamp holder comprises a limiting plate capable of rotating in a circumferential direction and a plurality of blades capable of swinging in a radial direction, and the limiting plate and the blades are in linkage arrangement, so that when the limiting plate rotates in the circumferential direction, all the blades are driven to synchronously and radially gather to clamp and align the axis of the rock sample with the axis of the clamp plate main body. The invention can realize accurate alignment of the rock sample and the axis of the pull head, and ensure the true and reliable test data.

Inventors

Sheng mao
QI ZHENHUI
Hao Xingyang
Ren Lejia
WANG XIAOQIONG
TIAN SHOUCENG
HUANG ZHONGWEI
LI GENSHENG

Assignees

中国石油大学(北京)

Dates

Publication Date: 20260508
Application Date: 20260112

Claims (10)

1. An adhesive centering device for direct tensile testing of rock, comprising: The clamping plate main body comprises a clamping plate pressing head and a clamping plate base, and the clamping plate pressing head and the clamping plate base are connected through a connecting rod and coaxially arranged; the centering clamp holder is arranged between the clamping plate pressure head and the clamping plate base and is used for clamping and centering the rock sample before bonding; The centering clamp holder comprises a limiting plate capable of rotating in the circumferential direction and a plurality of blades capable of swinging in the radial direction, wherein the limiting plate is configured in linkage with the blades, so that when the limiting plate rotates in the circumferential direction, all the blades are driven to synchronously and radially gather together, and the axis of the rock sample is clamped and aligned with the axis of the clamp plate main body.
2. The device according to claim 1, wherein the number of the connecting rods is 4, and the 4 connecting rods are uniformly distributed along the circumferential direction of the clamping plate main body and respectively connect the clamping plate pressing head with the centering clamp holder and the centering clamp holder with the clamping plate base, so that the clamping plate pressing head, the centering clamp holder and the clamping plate base are coaxial.
3. The device according to claim 1, wherein the centering holder further comprises a centering holder base, a groove part of the centering holder base is provided with a plurality of base blade fixing holes which are uniformly distributed in a ring shape, and one end of the blade is hinged with the base blade fixing holes through rivets so that the blade swings radially around the rivets in a gathering or spreading mode.
4. The apparatus of claim 1, wherein the centering clamp further comprises a centering clamp cover plate that covers over the limiting plate for shielding and axially limiting the limiting plate, the blade, and the rivet.
5. The device according to claim 1, wherein the blades are arc-shaped transmission members, the two ends of each blade are respectively provided with a hinge hole and a matching hole, the hinge holes are hinged with the base blade fixing holes through rivets, and the matching hole ends of all the blades face to the center of the device and are uniformly distributed on the circumference.
6. The device according to claim 1, wherein the limiting plate is provided with guide grooves corresponding to the number of the blades, the guide grooves are in sliding fit with rivets at the matching hole ends of the blades, and the guide grooves drive the rivets to drive the blades to synchronously and radially gather or scatter through the circumferential rotation of the limiting plate.
7. The apparatus of claim 1, further comprising a stud for connecting the clamp head to the tensile test upper pull head, the tensile test lower pull head to the clamp base, and the stud being adapted to a plurality of dimensional specifications of the pull head.
8. The apparatus of claim 1, further comprising a plate lifting adjustment device coupled to the centering gripper for driving the centering gripper to move in the direction of the axis of the cleat body to adjust the gripping position of the centering gripper.
9. The device of claim 8, wherein the plate lifting adjustment device comprises a plate lifting adjustment device base, a rotating handle and a plate lifting adjustment device bolt, wherein the rotating handle is in transmission connection with the plate lifting adjustment device bolt, and rotation of the rotating handle drives the plate lifting adjustment device bolt to drive the centering clamp to axially move.
10. A method of operation for the bonding centring of a rock direct tensile test, characterized in that it uses a device according to any one of claims 1-9, comprising the steps of: connecting a clamping plate pressing head of the clamping plate main body with the clamping plate base through a connecting rod, so that the clamping plate pressing head and the clamping plate base are coaxially arranged; The centering clamp holder is arranged between the clamping plate pressure head and the clamping plate base and comprises a limiting plate and a plurality of blades, wherein the limiting plate and the blades are in linkage configuration; Placing the rock sample in a clamping area of a centering clamp holder, rotating a limiting plate in a circumferential direction, driving all blades to radially gather synchronously, clamping the rock sample and aligning an axis of the rock sample with an axis of a clamp plate main body; The clamping plate pressure head and the upper pull head of the tensile test and the lower pull head of the tensile test are connected and fixed with the clamping plate base through the double-headed bolts; And (3) coating adhesive on the corresponding bonding parts of the rock sample and the upper and lower sliders, and maintaining the centering clamping state of the centering clamp until the adhesive is solidified, thus completing the coaxial bonding of the rock sample and the sliders.

Description

Bonding centering device for rock direct tensile test and operation method Technical Field The invention relates to the technical field of geotechnical mechanics, in particular to a bonding centering device for a rock direct tensile test and an operation method. Background In the engineering of hydraulic fracturing, well wall stabilization and the like in petroleum engineering, accurate testing of the tensile strength of rock depends on a direct tensile test, and the core difficulty of the test is the bonding centering of a rock sample and a tensile pull head. In the prior art, manual bonding or simple clamping tools lack a uniform coaxial line reference, and the clamping parts cannot synchronously cooperate, so that the axes of the rock sample and the pull head are easy to deviate. The improved cap-type device is difficult to realize active centering and is easy to generate additional bending moment. These problems directly cause axial load deviations from the sample axis, making the measured tensile strength inconsistent with the true value, affecting test data reliability. In view of the above problems, no effective solution has been proposed at present. Disclosure of Invention The embodiment of the specification provides a bonding centering device for a direct tensile test of rock and an operation method, so as to solve the problems of axis deviation and actual measurement tensile strength distortion caused by lack of a uniform coaxial line reference and incapability of synchronous cooperative action of a clamping part when a rock sample is bonded with a pull head in the direct tensile test. In a first aspect, embodiments of the present disclosure provide an adhesive centering device for direct tensile testing of rock, comprising: The clamping plate main body comprises a clamping plate pressing head and a clamping plate base, and the clamping plate pressing head and the clamping plate base are connected through a connecting rod and coaxially arranged; the centering clamp holder is arranged between the clamping plate pressure head and the clamping plate base and is used for clamping and centering the rock sample before bonding; The centering clamp holder comprises a limiting plate capable of rotating in the circumferential direction and a plurality of blades capable of swinging in the radial direction, wherein the limiting plate is configured in linkage with the blades, so that when the limiting plate rotates in the circumferential direction, all the blades are driven to synchronously and radially gather together, and the axis of the rock sample is clamped and aligned with the axis of the clamp plate main body. In some embodiments, the number of the connecting rods is 4, and the 4 connecting rods are uniformly distributed along the circumference of the clamping plate main body and respectively connect the clamping plate pressure head with the centering clamp holder and the centering clamp holder with the clamping plate base, so that the clamping plate pressure head, the centering clamp holder and the clamping plate base are coaxial. In some embodiments, the centering holder further comprises a centering holder base, a plurality of base blade fixing holes which are uniformly distributed in a ring shape are formed in a groove part of the centering holder base, one end of each blade is hinged with the base blade fixing holes through rivets, and the blades swing radially around the rivets in a gathering or scattering mode. In some embodiments, the centering clamp further comprises a centering clamp cover plate covering over the limiting plate for protecting and axially limiting the limiting plate, the blade, and the rivet. In some embodiments, the blades are arc-shaped transmission members, two ends of each blade are respectively provided with a hinge hole and a matching hole, the hinge holes are hinged with the base blade fixing holes through rivets, and the matching hole ends of all the blades face towards the center of the device and are uniformly distributed on the circumference. In some embodiments, the limiting plate is provided with guide grooves corresponding to the number of the blades, the guide grooves are in sliding fit with rivets at the ends of the matching holes of the blades, and the guide grooves drive the rivets to drive the blades to synchronously and radially gather or scatter through the circumferential rotation of the limiting plate. In some embodiments, the device further comprises a stud for connecting the clamp plate ram with the tensile test upper pull head, the tensile test lower pull head, and the clamp plate base, and the stud is adapted to multiple dimensional specifications of the pull head. In some embodiments, the device further comprises a plate lifting adjustment device connected to the centering gripper for driving the centering gripper to move in the direction of the axis of the cleat body to adjust the gripping position of the centering gripper. In some embodiments, the