CN117309213B - Nondestructive testing equipment and method for wood structure - Google Patents
Nondestructive testing equipment and method for wood structure Download PDFInfo
- Publication number
- CN117309213B CN117309213B CN202311615471.9A CN202311615471A CN117309213B CN 117309213 B CN117309213 B CN 117309213B CN 202311615471 A CN202311615471 A CN 202311615471A CN 117309213 B CN117309213 B CN 117309213B
- Authority
- CN
- China
- Prior art keywords
- nail
- wood
- force
- force application
- measured
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 239000002023 wood Substances 0.000 title claims abstract description 228
- 238000000034 method Methods 0.000 title claims abstract description 32
- 238000009659 non-destructive testing Methods 0.000 title claims description 24
- 230000005540 biological transmission Effects 0.000 claims abstract description 33
- 238000012544 monitoring process Methods 0.000 claims abstract description 22
- 229910000831 Steel Inorganic materials 0.000 claims description 35
- 239000010959 steel Substances 0.000 claims description 35
- 238000005452 bending Methods 0.000 claims description 27
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 12
- 238000007689 inspection Methods 0.000 claims description 6
- 238000005553 drilling Methods 0.000 claims description 5
- 230000001133 acceleration Effects 0.000 claims description 4
- 230000005484 gravity Effects 0.000 claims description 4
- 241001079814 Symphyotrichum pilosum Species 0.000 claims description 2
- 235000004224 Typha angustifolia Nutrition 0.000 claims description 2
- 238000001514 detection method Methods 0.000 abstract description 68
- 230000008569 process Effects 0.000 abstract description 11
- 230000001066 destructive effect Effects 0.000 abstract description 4
- 238000010276 construction Methods 0.000 description 5
- 239000003381 stabilizer Substances 0.000 description 5
- 238000012360 testing method Methods 0.000 description 5
- 230000009471 action Effects 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 230000008439 repair process Effects 0.000 description 3
- 230000007547 defect Effects 0.000 description 2
- 238000011156 evaluation Methods 0.000 description 2
- 238000009434 installation Methods 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 241000587161 Gomphocarpus Species 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 210000000988 bone and bone Anatomy 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 239000003822 epoxy resin Substances 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 239000003292 glue Substances 0.000 description 1
- 238000011065 in-situ storage Methods 0.000 description 1
- 230000002427 irreversible effect Effects 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 229920000647 polyepoxide Polymers 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000002787 reinforcement Effects 0.000 description 1
- 238000009418 renovation Methods 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L5/00—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L5/00—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes
- G01L5/0028—Force sensors associated with force applying means
- G01L5/0033—Force sensors associated with force applying means applying a pulling force
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/20—Investigating strength properties of solid materials by application of mechanical stress by applying steady bending forces
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N9/00—Investigating density or specific gravity of materials; Analysing materials by determining density or specific gravity
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
Abstract
The invention discloses nondestructive detection equipment and method for a wood structure, which aim at solving the problems that the existing wood structure detection equipment is long in time consumption and high in cost, cannot guarantee detection accuracy and has destructive effect on wood components. The detection equipment comprises a force application frame arranged on the wood component to be detected, a force application device arranged at the top of the force application frame, a force sensor, a nail pressing head and a nail positioner which are sequentially connected to the bottom of the force application device along the axis, wherein the force sensor is in signal connection with the data acquisition and transmission device, and a nail cap is buckled on the nail positioner, and the bottom of a nail is nailed into the wood component to be detected. The detection method comprises the following steps: the method comprises the steps of pre-nailing nails into pre-drilled holes of wood components to be detected, applying downward pressure along an axis by a force application device until the nails are pressed down to a specified depth, applying upward pulling force by the force application device, driving a nail positioner to lift upwards by a nail pressing head until the nails are pulled out of the wood components to be detected, respectively acquiring initial data of a detection process and monitoring data after nailing by a force sensor, and calculating the nail holding force of the wood components to be detected.
Description
Technical Field
The invention relates to the technical field of wood structure detection, in particular to nondestructive detection equipment and method for a wood structure.
Background
The wood structure building has the advantages of excellent anti-seismic performance, environment friendliness, convenience in construction and the like, a large number of existing wood structure ancient buildings, brick-wood mixed structures and other excellent existing buildings in China, and a plurality of modern wood structure buildings are newly built in recent years. In the process of processing, storing and transporting the wooden materials adopted by the wooden structure building, various reversible or irreversible physical and chemical changes can continuously occur along with the time, in addition, in the long-term service process of the wooden structure building, the wooden components are easy to generate damage defects due to the influence of biological damage, environmental influence or service life and the like, the mechanical property is reduced, and the structural safety is influenced; in urban renovation, wood-structured buildings often make the best use of old wood during in-situ original appearance repair, but lack reliable technical means in determining the residual strength of the wood elements. Therefore, it is necessary to perform material property detection on the wood member to obtain the physical and mechanical properties of the wood, thereby evaluating the safety condition of the wood structure.
The wood structure is commonly connected by nails, such as roof boards and floor boards are connected with beams by nails, and wall bones are connected with bottom boards by inclined nails. Nails used in wood structures are mainly composed of round steel nails and screws, and the grip strength of wood is an important parameter for evaluating the performance of wood members. The traditional detection method for the mechanical properties of the wood members adopts a universal mechanical detector to perform destructive detection on a wood cleaning test piece, and has the following defects:
1. taking destructive detection as a main method, intercepting a sample on the existing wood member, and detecting the structural member with long time consumption and damage the integrity of the existing building member;
2. the existing wood member detection equipment is large in body quantity, complex in operation and not beneficial to on-site detection and popularization;
3. important performance parameters such as density and bending strength of the wood member cannot be obtained through rapid calculation according to the nail holding force, other detection is needed to obtain the density and the bending strength, and the detection cost is increased;
4. the nailing depth and verticality of the nails are difficult to control in the detection process, and the accuracy is difficult to guarantee.
Disclosure of Invention
The method aims at the problems that the existing wood structure detection equipment and method are long in detection time consumption and high in cost, the detection accuracy cannot be guaranteed, and the wood structure detection equipment and method are destructive to wood members. The invention aims to provide nondestructive testing equipment and method for a wood structure.
The technical scheme adopted for solving the technical problems is as follows: a wood-based nondestructive inspection apparatus comprising: the device comprises a force application frame, a force application device, a force sensor, a nail pressing head, a nail positioner and a data acquisition and transmission device, wherein the force application frame is arranged on a wood component to be tested, the force application device is arranged at the top of the force application frame, the nail positioner, the nail pressing head, the force sensor and the force application device are sequentially connected from bottom to top along an axis, a nail cap can be buckled on the nail positioner, the tip of a nail is perpendicularly nailed into the wood component to be tested, one end of the nail pressing head is connected with the force sensor, the other end of the nail pressing head penetrates the nail positioner and can be contacted with the upper surface of the nail, and the force sensor is in signal connection with the data acquisition and transmission device.
The nondestructive testing equipment for the wood structure comprises a force application frame erected on a wood component to be tested, a force application device arranged at the top of the force application frame, a force sensor, a nail pressing head and a nail positioner, wherein the force sensor, the nail pressing head and the nail positioner are sequentially connected to the bottom of the force application device along an axis, the force sensor is in signal connection with a data acquisition and transmission device, a nail cap is buckled in an inner cavity of the nail positioner, and the bottom of a nail is nailed into the wood component to be tested. When the wood component nail holding force is detected, the force application device applies downward pressure, the nail pressing head moves downwards until the nail is pressed down to a specified depth, and the force sensor transmits monitoring data to the data acquisition and transmission device; the force application device applies upward tension, and the nail pressing head drives the nail positioner to lift upwards until the nails are pulled out of the wood component to be detected under the action of pulling-out force. The detection device has the advantages that the same detection equipment is utilized to realize the nailing in and the nailing out of nails, and the detection result of the nail holding force of the wood member can be obtained rapidly on site, so that the overall mechanical property of the wood structure is estimated specifically, the operation is convenient and rapid, the detection efficiency is improved, the detection cost is reduced, and the detection device is suitable for site rapid detection and estimation of the wood structure building. The detection equipment cannot cause structural damage and appearance influence on the wood member, and the integrity of the wood structure is guaranteed. The nail positioner is utilized to ensure that nails are nailed perpendicular to the surface of the wood component to be detected, the nailing depth can be accurately measured, errors caused by inclination of the nails are avoided, and the accuracy of detection results is improved.
Further, the nail pressure head comprises threaded rod and perpendicular clamp plate that connects in its bottom, the nail locator includes the clamping part, and connect a pair of stabilizer blade in the clamping part bottom, the clamping part has a cavity that the horizontal direction link up, the top of clamping part is equipped with a preformed hole, the threaded rod top of nail pressure head is equipped with the external screw thread, the threaded rod runs through the preformed hole of clamping part and with be fixed in a telescopic thread connection of force sensor bottom, the clamp plate buckle is in the clamping part cavity and can follow its lateral wall vertical movement, the transversal L shape of personally submitting of stabilizer blade, a pair of stabilizer blade is relative and the interval sets up, the horizontal end of stabilizer blade supports on the wooden component that awaits measuring, the clearance that the vertical end of a pair of stabilizer blade constitutes communicates with the clamping part cavity, the nail pole of nail passes the clearance and the point portion nail is gone into the wooden component that awaits measuring.
Further, when the nail is a round steel nail, the pressing plate of the nail pressing head is a cross rod, the two ends of the cross rod are respectively provided with a rotatable spherical hinge, and the spherical hinges at the two ends are contacted with the side walls at the two sides of the clamping part.
Further, when the nail is a screw, the pressing plate of the nail pressing head is a circular turntable, the drill bit at the bottom end of the threaded rod is matched with the notch at the top of the screw, and the edge of the circular turntable is contacted with the side walls at two sides of the clamping part. Further, scales are arranged on the side wall of the clamping part of the nail positioner.
Further, steel teeth are arranged at the bottoms of the horizontal ends of the pair of supporting legs of the nail positioner.
Further, the force application frame comprises two supports symmetrically arranged on two sides of the force application device along the axis of the force application device, each support comprises an arc-shaped sleeve, a support rod and a steel hoop, one end of each arc-shaped sleeve is connected to the force application device, the other end of each arc-shaped sleeve and the support rod are provided with a plurality of bolt holes corresponding to each other in position, the arc-shaped sleeves can be sleeved at one end of each support rod and connected with the corresponding bolt holes, the steel hoops are connected to the other end of each support rod, and the steel hoops can be sleeved on wood members to be tested and locked and fixed through the bolts.
Further, the device further comprises a connecting piece vertically arranged between the force application device and the force sensor, the connecting piece comprises a force application rod and a connecting rod, the force application rod is vertically fixed at the bottom of the force application device, an internal thread is arranged at the bottom of the force application rod, an external thread matched with the internal thread of the force application rod is arranged at the top of the connecting rod, one end of the connecting rod is in threaded connection with the force application rod, and the other end of the connecting rod is in threaded connection with the sleeve barrel fixed at the top of the force sensor.
In addition, the invention also provides a nondestructive testing method for the wood structure, which comprises the following steps:
s1: pre-drilling holes at the positions of the wood component to be detected, which are required to be detected by the nail holding force, vertically inserting the tip parts of the nails into the drilled holes, assembling the wood structure nondestructive testing equipment, and adjusting the mounting positions of the force application frames to enable the nail positioners to be sleeved on the nails and coincide with the axes of the nails;
s2: the force application device applies downward pressure, the nail pressing head moves downwards until the bottom surface of the nail pressing head contacts with the upper surface of the nail, the force sensor obtains monitoring data in an initial state, the nail pressing head is continuously pressed down until the nail is pressed down to a designated depth, the force sensor obtains the monitoring data at the moment, and the monitoring data are transmitted to the data acquisition and transmission device; the force application device applies upward tension, and the nail pressing head drives the nail positioner to lift upwards until the nails are pulled out of the wood component to be detected;
s3: the data acquisition and transmission device calculates the nail-holding force of the wood component to be detected according to the monitoring data, and the calculation formula of the nail-holding force is as follows:
；
wherein P is max The unit N is the maximum pulling force detected when the nail is pulled out;
m 1 the mass of the nail positioner is kg;
m 2 the unit is kg of the mass of the nailing head;
g is gravity acceleration, and the unit is N/kg;
f is the nail-holding force of the wood component to be measured, and the unit is N/mm;
l is the depth of the nail which is nailed into the wood component to be measured, and the unit is mm.
According to the nondestructive testing method for the wood structure, firstly, a hole is drilled in advance in a position, needing to be subjected to nail holding force detection, of a wood component to be tested, the tip part of a nail is vertically inserted into the drilled hole, a force application frame and a force application device are installed on the wood component to be tested, a force sensor, a nail pressing head and a nail positioner are sequentially connected, so that the nail can be buckled on the nail positioner, the force application device applies downward pressure along an axis until the nail is pressed down to a designated depth, then the force application device applies upward pulling force, the nail pressing head drives the nail positioner to lift up until the nail is pulled out of the wood component to be tested, the force sensor respectively acquires initial data in a detection process and monitoring data after the nail is nailed, and the nail holding force of the wood component to be tested is calculated. According to the detection method, nails are nailed into pre-drilled holes of the wood components to be detected in advance, pressure or tensile force is applied to the nails through the force application device, meanwhile, monitoring data are acquired through the force sensor connected with the nail pressing head, the nailing and nail holding force anti-pulling detection of the nails are realized on the same detection device, the nail holding force detection of the wood components can be rapidly carried out on a wood structure construction site, the operation is simple and convenient, the time consumption is short, the detection efficiency is improved, and the detection method is suitable for rapid detection and evaluation of the wood structure construction site; the nail positioner ensures that nails are nailed from the surface vertical to the wood component to be detected, so that the nailing depth is accurately measured, measurement errors caused by inclination of the nails are avoided, and the accuracy of a detection result is improved; the detection process can not cause structural damage to the wood component to be detected, the appearance of the wood component is basically not affected, and the integrity of the wood structure is ensured.
Still further, it further comprises step S4: when the nails are round steel nails, the density of the wood component to be measured is calculated as follows:
；
wherein ρ is the density of the wood member to be measured, and the unit is g/cm 3 ；
k 1 Adjusting the coefficient for the density;
f is the nail-holding force of the wood component to be measured, and the unit is N/mm;
w is the absolute water content of the wood component to be measured, and the units are expressed in percentage;
the flexural strength of the wood member to be measured was calculated as follows:
；
wherein,the bending strength of the wood component to be tested is expressed in MPa;
k 2 the bending strength adjustment coefficient is used;
f is the nail-holding force of the wood component to be measured, and the unit is N/mm;
w is the absolute water content of the wood component to be measured, and the units are expressed in percentage.
Still further, it further comprises step S4: when the nails are screws, the density of the wood component to be measured is calculated as follows;
；
wherein ρ is the density of the wood member to be measured, and the unit is g/cm 3 ；
k 1 Adjusting the coefficient for the density;
f is the nail-holding force of the wood component to be measured, and the unit is N/mm;
w is the absolute water content of the wood component to be measured, and the units are expressed in percentage;
the flexural strength of the wood member to be measured was calculated as follows:
；
wherein,the bending strength of the wood component to be tested is expressed in MPa;
k 2 the bending strength adjustment coefficient is used;
f is the nail-holding force of the wood component to be measured, and the unit is N/mm;
w is the absolute water content of the wood component to be measured, and the units are expressed in percentage.
Drawings
FIG. 1 is a schematic diagram of a nondestructive inspection apparatus for wood structures according to an embodiment of the present invention;
FIG. 2 is a schematic view of a staple positioner according to one embodiment of the present invention;
FIG. 3 is a schematic view of a staple positioner according to another embodiment of the present invention.
The labels in the figures are as follows:
a wood member 1 to be measured; a nail 2; a data acquisition and transmission device 3; an arc-shaped sleeve 11; a support bar 12; bolt holes 14; a steel hoop 15; a force application device 20; a connecting member 30; a force application lever 31; a link 32; a force sensor 40; sleeve one 41; sleeve two 42; a stapling head 50; a threaded rod 51; a pressing plate 52; a spherical hinge 54; a drill 56; a circular turntable 57; a staple locator 60; a clamping portion 61; legs 62; steel teeth 63; scale 64.
Detailed Description
The invention is described in further detail below with reference to the drawings and the specific examples. It should be noted that the drawings are in a very simplified form and are all to a non-precise scale, merely for convenience and clarity in aiding in the description of embodiments of the invention. For convenience of description, the "upper" and "lower" described below are consistent with the upper and lower directions of the drawings, but this should not be construed as a limitation of the technical scheme of the present invention.
The wood-structure nondestructive testing apparatus of the present invention will be described with reference to fig. 1 to 3, which includes: the device comprises a force application frame, a force application device 20, a force sensor 40, a nail pressure head 50, a nail positioner 60 and a data acquisition and transmission device 3, wherein the force application frame is arranged on a wood component 1 to be tested, the force application device 20 is arranged at the top of a frame body of the force application frame, the nail positioner 60, the nail pressure head 50, the force sensor 40 and the force application device 20 are sequentially connected from bottom to top along an axis, a nail cap of a nail 2 is buckled on the nail positioner 60, the tip of the nail 2 is nailed into the wood component 1 to be tested, the nail positioner 60 is used for clamping and positioning the nail 2, one end of the nail pressure head 50 is connected with the force sensor 40, the other end of the nail pressure head 50 passes through the nail positioner 60 and can be in contact with the upper surface of the nail 2, the force application device 20 drives the force sensor 40 and the nail pressure head 50 to move or rotate along the axis direction, so that the nail pressure head 50 can drive the nail 2 to be led into or pulled out of the wood component 1 to be tested, and the force sensor 40 is connected with the data acquisition and transmission device 3 in a signal manner, and the monitoring data is used for transmitting to the data acquisition and transmission device 3.
The nondestructive testing equipment for the wood structure comprises a force application frame which is erected on a wood component 1 to be tested, a force application device 20 which is arranged at the top of the force application frame, a force sensor 40, a nail pressing head 50 and a nail positioner 60 which are sequentially connected to the bottom of the force application device 20 along the axis, wherein the force sensor 40 is in signal connection with a data acquisition and transmission device 3, the top of a nail 2 is buckled in an inner cavity of the nail positioner 60, and the bottom of the nail 2 is nailed into the wood component 1 to be tested. When the holding force of the wood member is detected, the force application device 20 applies downward pressure, the nail pressing head 50 moves downwards until the nail 2 is pressed down to a specified depth, and the force sensor 40 transmits monitoring data to the data acquisition and transmission device 3; the force application device 20 applies upward pulling force, and the nail pressing head 50 drives the nail positioner 60 to lift upwards until the nails 2 are pulled out of the wood component 1 to be tested under the action of the pulling force. The same detection equipment is utilized to realize the nailing in and the extraction of the nails 2, and the detection result of the nail holding force of the wood member can be obtained rapidly on site, so that the overall mechanical property of the wood structure is estimated specifically, the operation is convenient and rapid, the detection efficiency is improved, the detection cost is reduced, and the method is suitable for site rapid detection and estimation of the wood structure building. The detection equipment cannot cause structural damage and appearance influence on the wood member, and the integrity of the wood structure is guaranteed. The nail positioner 60 is utilized to ensure that the nails 2 are nailed perpendicularly to the surface of the wood member 1 to be detected, the nailing depth can be accurately measured, errors caused by inclination of the nails are avoided, and the accuracy of the detection result is improved. The nondestructive testing equipment for the wood structure is suitable for round steel nails and is also suitable for nail holding force detection of screws.
As shown in fig. 1, the nailing head 50 is composed of a threaded rod 51 and a pressing plate 52 vertically connected to the bottom end of the threaded rod 51, the nailing positioner 60 includes a clamping portion 61, and a pair of legs 62 connected to the bottom of the clamping portion 61, the clamping portion 61 has a cavity penetrating in a horizontal direction, a preformed hole is provided at the top of the clamping portion 61, an external thread is provided at the top of the threaded rod 51, the threaded rod 51 penetrates the preformed hole of the clamping portion 61 and is in threaded connection with a sleeve 41 fixed to the bottom of the force sensor 40, the pressing plate 52 fastened to the cavity of the clamping portion 61 can vertically move along the side wall thereof, the cross section of the legs 62 is in an L shape, the pair of legs 62 are opposite and are arranged at intervals, the horizontal ends are supported on the wood member 1 to be measured, a gap formed by the vertical ends of the pair of legs 62 is communicated with the cavity of the clamping portion 61, and the nailing rod of the nailing 2 penetrates the gap and the tip is nailed into the wood member 1 to be measured. In this embodiment, the pin positioner 60 is made of stainless steel material, and the gap width between the pair of legs 62 is 1.5 times the diameter of the pin 2, so that the pin 2 is conveniently controlled to vertically nail into the wood member 1 to be measured.
As shown in fig. 2, when the nail 2 is a round steel nail, the pressing plate 52 of the nail pressing head 50 is a cross bar, and two ends of the cross bar are provided with rotatable spherical hinges 54, so that the two ends of the cross bar can slide along the side walls of the clamping part 61. When the holding force is detected, the force application device 20 applies vertical pressure or pulling force, and the round steel nails are pressed down or pulled out through the nail pressing head 50, so that the spherical hinges 54 at the two ends of the cross rod of the nail pressing head 50 can reduce friction force between the cross rod and the side wall of the nail positioner 60. The diameter of the shank of the round steel nail in this example was 2.5mm.
As shown in fig. 3, when the nail 2 is a screw, the pressing plate 52 of the nail pressing head 50 is a circular turntable 57, the drill 56 at the bottom end of the threaded rod 51 is matched with the notch at the top of the screw, and the edge of the circular turntable 57 is contacted with the side walls at two sides of the clamping part 61. In the detection of the grip force, the force application device 20 applies a rotational force about the axis, and screws are screwed into or out of the wood member 1 to be measured through the drill 56 at the bottom of the nail head 50. The shank diameter of the screw in this embodiment was 4mm.
As shown in fig. 1, the side wall of the clamping portion 61 of the nail positioner 60 is provided with graduations 64 for precisely controlling the depth of the driven wood member.
As shown in fig. 1, steel teeth 63 are provided at the bottoms of the horizontal ends of a pair of legs 62 of the pin positioner 60, and the steel teeth 63 are pressed into the wood member 1 to be tested, so that the pin positioner 60 is prevented from sliding in the detection process.
With continued reference to fig. 1, the force application frame includes two brackets symmetrically disposed on two sides of the force application device 20 along an axis, and each bracket includes an arc-shaped sleeve 11, a support rod 12 and a steel hoop 15. One end of the arc sleeve 11 is connected to the force application device 20, the other end of the arc sleeve 11 and the supporting rod 12 are provided with a plurality of bolt holes 14 with corresponding positions, so that the arc sleeve 11 can be sleeved at one end of the supporting rod 12 and connected with the supporting rod through bolts, the installation height of the force application frame can be flexibly adjusted by adjusting the position of inserting the opposite threaded rod into the bolt holes 14, and the requirements of on-site testing of wood component holding force with different lengths and different nailing depths are met. The steel hoop 15 is connected to the other end of the supporting rod 12, and the steel hoop 15 can be sleeved on the wood member 1 to be tested and locked and fixed by bolts. In this embodiment, the steel hoop 15 is in a semicircle shape, which is matched with the cross section shape of the wood member 1 to be tested, the steel hoop 15 is 20mm wide and 4mm thick, and the steel hoop 15 is fastened to the wood member 1 to be tested and fastened by a butt bolt. More preferably, the inner wall of the steel hoop 15 is provided with a rubber layer made of epoxy resin glue, the width of the rubber layer is 30mm, the thickness of the rubber layer is 6mm, and the contact part of the steel hoop 15 and the wood member is prevented from being concentrated in stress and the wood member is prevented from being partially pressed and yielding in the detection process.
With continued reference to fig. 1, the nondestructive testing apparatus for wood structure further includes a connecting member 30 vertically disposed between the force applying device 20 and the force sensor 40, the connecting member 30 includes a force applying rod 31 and a connecting rod 32, the force applying rod 31 is vertically fixed at the bottom of the force applying device 20, the bottom of the force applying rod 31 is provided with internal threads, the top of the connecting rod 32 is provided with external threads matching with the internal threads of the force applying rod 31, one end of the connecting rod 32 is in threaded connection with the force applying rod 31, and the other end of the connecting rod 32 is in threaded connection with a second sleeve 42 fixed at the top of the force sensor 40.
The nondestructive testing method for the wood structure is described with reference to fig. 1 to 3, and comprises the following specific steps:
s1: the method comprises the steps of pre-drilling a part, needing to be subjected to nail holding force detection, of a wood component 1 to be detected, wherein the diameter of the hole is 70% of the diameter of a nail, the pre-drilling depth is 80% of the length of the nail, the tip of the nail 2 is just vertically inserted into the drill hole to be in an initial state, assembling the wood structure nondestructive detection device, adjusting the installation positions of a force application frame and components in the frame, fixing the force application frame on the wood component 1 to be detected through a steel hoop 15, adjusting the distance between an arc sleeve 11 and a supporting rod 12 of the force application frame according to the length of the nail 2 and bolting, sleeving a clamping part 61 of a nail positioner 60 on the nail 2, enabling a nail cap to be positioned in a cavity of the clamping part 61, enabling the nail rod to penetrate through a gap between a pair of supporting legs 62, knocking steel teeth 63 at the bottom of the nail positioner 60 onto the wood component 1 to be detected after the whole wood structure nondestructive detection device is adjusted to be in a proper state, preventing the nail positioner 60 from moving misplacement in the detection process, and adjusting the positions of all components in the force application frame body through a telescopic force application rod 31 to be in a proper position;
s2: starting the force application device 20 and the data acquisition and transmission device 3, applying downward pressure by the force application device 20, slowly moving the nail pressing head 50 downwards until the bottom surface of the nail pressing head is just contacted with the upper surface of the nail 2 as an initial state, recording the corresponding scale 64 of the nail pressing head 50, simultaneously obtaining monitoring data of the initial state by the force sensor 40, continuously slowly pressing the nail pressing head 50 downwards until the nail 2 is pressed to a specified depth, obtaining the change distance of the corresponding scale 64 of the nail pressing head 50 as the nailing depth, obtaining the monitoring data after nailing at the moment by the force sensor 40, and transmitting the monitoring data to the data acquisition and transmission device 3; after the nails 2 are pressed down to a specified depth, the force application device 20 slowly applies upward pulling force, the nail pressing head 50 is pulled to be in contact with the upper surface of the clamping part 61 of the nail positioner 60, and then the steel teeth 63 at the bottom of the nail positioner 60 are pulled out, and as the depth of the steel teeth 63 pressed into the wood component 1 to be detected is small, the pulling force of the steel teeth 63 is far smaller than the pulling force of the nails 2, the nail pressing head 50 drives the nail positioner 60 to continue to lift upwards until the nails 2 are pulled out of the wood component 1 to be detected under the action of the pulling force;
s3: the data acquisition and transmission device 3 acquires the maximum load P according to the step S2 max The nail-holding force of the wood member 1 to be measured is calculated and displayed on the display screen of the data acquisition and transmission device 3, and the calculation formula of the nail-holding force is as follows:
；
wherein P is max The unit N is the maximum pulling force detected when the nail is pulled out;
m 1 the mass of the staple locator 60 is in kg;
m 2 the unit is kg of the mass of the nailing head 50;
g is gravity acceleration, and the unit is N/kg;
f is the nail-holding force of the wood member 1 to be measured, and the unit is N/mm;
l is the depth of penetration in mm.
According to the nondestructive testing method for the wood structure, firstly, a hole is drilled in advance in a position, needing to be subjected to nail holding force detection, of a wood component 1 to be tested, the tip of a nail 2 is vertically inserted into the drilled hole, a force application frame and a force application device 20 are installed on the wood component 1 to be tested, and a force sensor 40, a nail pressing head 50 and a nail positioner 60 are sequentially connected, so that the nail 2 can be buckled on the nail positioner 60, downward pressure is applied to the force application device 20 along an axis until the nail 2 is pressed down to a designated depth, then, upward pulling force is applied to the force application device 20, the nail pressing head 50 drives the nail positioner 60 to be lifted upwards until the nail 2 is pulled out of the wood component 1 to be tested, initial data of a detection process and monitored data after nailing are respectively acquired by the force sensor 40, and the nail holding force of the wood component 1 to be tested is calculated. According to the detection method, nails 2 are nailed into pre-drilled holes of the wood component 1 to be detected in advance, pressure or tensile force is applied to the nails 2 through the force application device 20, meanwhile, monitoring data are acquired through the force sensor 40 connected with the nail pressing head 50, the nailing and nail holding force pulling-resistant detection of the nails 2 is realized on the same detection device, the nail holding force detection of the wood component can be rapidly carried out on a wood structure construction site, the operation is simple and convenient, the time consumption is short, the detection efficiency is improved, and the detection method is suitable for rapid detection and evaluation of the wood structure construction site; the nail positioner 60 ensures that the nails 2 are nailed from the surface perpendicular to the wood member 1 to be detected, so that the nailing depth is accurately measured, measurement errors caused by inclination of the nails 2 are avoided, and the accuracy of the detection result is improved; the detection process can not cause structural damage to the wood component 1 to be detected, the appearance of the wood component is basically not affected, and the integrity of the wood structure is ensured.
Further, the nondestructive testing method for the wood structure further comprises the step S4 of: inputting the adjustment coefficients of the moisture content, the density and the bending strength of the wood component 1 to be tested on the data acquisition and transmission device 3, calculating the density and the bending strength of the wood component 1 to be tested by the data acquisition and transmission device 3, and displaying the density and the bending strength at the corresponding position of a display screen of the data acquisition and transmission device 3;
when the nails 2 are round steel nails, the density of the wood member 1 to be measured is calculated as follows:
；
wherein ρ is the density of the wood member to be measured, and the unit is g/cm 3 ；
k 1 For density adjustment, the driving direction is the wood grain-following directionk 1 Taking 1.56, when the nailing direction is the wood transverse grain directionk 1 Taking 1.15;
f is the nail-holding force of the wood member 1 to be measured, the unit is N/mm, and the nail-holding force can be measured by the force sensor 40 and is output by the data acquisition and transmission device 3;
w is the absolute water content of the wood member 1 to be measured, namely the percentage of the mass of water contained in the wood to the mass of the full-dry wood, and the unit is expressed by percentage;
the bending strength of the wood member 1 to be measured was calculated as follows:
；
wherein,the bending strength of the wood component to be tested is expressed in MPa;
k 2 for adjusting the coefficient of bending strength, the direction of the nails 2 is along the grain direction of the woodk 2 Taking 1.63, when the direction of the nail 2 is the wood transverse grain directionk 2 Taking 1.12;
f is the holding force of the wood member 1 to be measured, the holding force is N/mm, and the holding force can be measured by the force sensor 40 and is output by the data acquisition and transmission device 3;
w is the absolute moisture content of the wood member 1 to be measured, i.e. the percentage of the mass of moisture contained in the wood to the mass of the whole dry wood, the units being expressed in percentages.
Further, the nondestructive testing method for the wood structure further comprises the step S4 of: inputting the adjustment coefficients of the moisture content, the density and the bending strength of the wood component 1 to be tested on the data acquisition and transmission device 3, calculating the density and the bending strength of the wood component 1 to be tested by the data acquisition and transmission device 3, and displaying the density and the bending strength at the corresponding position of a display screen of the data acquisition and transmission device 3;
when the nails 2 are screws 2, calculating the density of the wood member 1 to be measured as follows;
；
wherein ρ is the density of the wood member 1 to be measured, and the unit is g/cm 3 ；
k 1 For density adjustment, the driving direction is the wood grain-following directionk 1 Taking 0.68, the direction of the nail 2 is the wood horizontal directionIn the direction of the linesk 1 Taking 1.1;
f is the nail holding force of the wood component to be measured, the unit is N/mm, and the nail holding force can be measured by the force sensor 40 and is output by the data acquisition and transmission device 3;
w is the absolute water content of the wood member 1 to be measured, namely the percentage of the mass of water contained in the wood to the mass of the full-dry wood, and the unit is expressed by percentage;
the bending strength of the wood member 1 to be measured was calculated as follows:
；
wherein,the bending strength of the wood component to be tested is expressed in MPa;
k 2 for adjusting the coefficient of bending strength, the nailing direction is along the grain direction of the woodk 2 Taking 0.72 of the wood, and when the nailing direction is the wood transverse grain directionk 2 Taking 1.1;
f is the nail-holding force of the wood member 1 to be measured, the unit is N/mm, and the nail-holding force can be measured by the force sensor 40 and is output by the data acquisition and transmission device 3;
w is the absolute moisture content of the wood member 1 to be measured, i.e. the percentage of the mass of moisture contained in the wood to the mass of the whole dry wood, the units being expressed in percentages.
Because the density and the bending strength are important physical and mechanical properties of the wood, the mechanical properties and damage conditions of the wood component can be specifically evaluated through the density and the bending strength, and a basis is provided for the protection repair and the reinforcement repair of the wood structure building. According to the nondestructive testing method for the wood structure, the grip strength of the wood structure 1 to be tested is detected on site, the density and the bending strength of the wood structure 1 to be tested are obtained through calculation according to the parameters such as the moisture content, the grip strength value and the wood cis-grain or trans-grain of the wood structure 1 to be tested, and the density and the bending strength performance data of the wood structure 1 to be tested can be obtained quickly and conveniently without other tests, so that the overall mechanical property of the wood structure can be evaluated specifically, and the testing time and the testing cost are saved; and the calculation formula of the wood density and the bending strength is obtained by selecting parameters which are strongly related to the wood nail-holding force value according to a large number of detection results, and the accuracy is high.
The above description is only illustrative of the preferred embodiments of the present invention and is not intended to limit the scope of the present invention, and any alterations and modifications made by those skilled in the art based on the above disclosure are intended to fall within the scope of the claims.
Claims (8)
1. A wood-based nondestructive testing apparatus, comprising: the device comprises a force application frame, a force application device, a force sensor, a nail pressing head, a nail positioner and a data acquisition and transmission device, wherein the force application frame is arranged on a wood component to be tested, the force application device is arranged at the top of the force application frame, the nail positioner, the nail pressing head, the force sensor and the force application device are sequentially connected from bottom to top along an axis, a nail cap can be buckled on the nail positioner, the tip of a nail is perpendicularly nailed into the wood component to be tested, one end of the nail pressing head is connected with the force sensor, the other end of the nail pressing head penetrates through the nail positioner and can be contacted with the upper surface of the nail, and the force sensor is in signal connection with the data acquisition and transmission device;
the nail pressure head comprises a threaded rod and a pressing plate vertically connected to the bottom end of the threaded rod, the nail positioner comprises a clamping part and a pair of supporting legs connected to the bottom of the clamping part, the clamping part is provided with a cavity which is communicated in the horizontal direction, the top of the clamping part is provided with a preformed hole, the top of the threaded rod of the nail pressure head is provided with external threads, the threaded rod penetrates through the preformed hole of the clamping part and is in threaded connection with a sleeve fixed to the bottom of the force sensor, the pressing plate is buckled in the cavity of the clamping part and can vertically move along the side wall of the clamping part, the cross section of each supporting leg is L-shaped, the supporting legs are opposite and are arranged at intervals, the horizontal ends of the supporting legs are supported on a wood component to be detected, a gap formed by the vertical ends of the supporting legs are communicated with the cavity of the clamping part, the nail rod of the nail penetrates through the gap and is nailed into the wood component to be detected, and the side wall of the clamping part of the nail positioner is provided with scales.
2. The wood-based nondestructive testing apparatus of claim 1, wherein: when the nail is a round steel nail, the pressing plate of the nail pressing head is a cross rod, two ends of the cross rod are respectively provided with a rotatable spherical hinge, and the spherical hinges at two ends are contacted with the side walls at two sides of the clamping part.
3. The wood-based nondestructive testing apparatus of claim 1, wherein: when the nail is a screw, the pressing plate of the nail pressing head is a circular turntable, the drill bit at the bottom end of the threaded rod is matched with the notch at the top of the screw, and the edge of the circular turntable is contacted with the side walls at two sides of the clamping part.
4. The wood-based nondestructive testing apparatus of claim 1, wherein: the bottom of the horizontal ends of the pair of support legs of the nail positioner is provided with steel teeth.
5. The wood-based nondestructive testing apparatus of claim 1, wherein: the force application frame comprises two brackets symmetrically arranged on two sides of the force application device along the axis of the force application device, each bracket comprises an arc-shaped sleeve, a support rod and a steel hoop, one end of each arc-shaped sleeve is connected to the force application device, the other end of each arc-shaped sleeve and the support rod are provided with a plurality of bolt holes corresponding to each other in position, the arc-shaped sleeves can be sleeved at one end of each support rod and connected with the corresponding bolt holes, the steel hoops are connected to the other end of each support rod, and the steel hoops can be sleeved on wood members to be tested and locked and fixed by the bolts.
6. The wood-based nondestructive testing apparatus of claim 1, wherein: the connecting piece comprises a force application rod and a connecting rod, wherein the force application rod is vertically fixed at the bottom of the force application device, an internal thread is arranged at the bottom of the force application rod, an external thread matched with the internal thread of the force application rod is arranged at the top of the connecting rod, one end of the connecting rod is in threaded connection with the force application rod, and the other end of the connecting rod is in threaded connection with a sleeve barrel fixed at the top of the force sensor.
7. A nondestructive inspection method for a wooden structure using the nondestructive inspection apparatus for a wooden structure according to any one of claims 1 to 6, characterized by comprising the steps of:
s1: pre-drilling holes at the positions of the wood component to be detected, which are required to be detected by the nail holding force, vertically inserting the tip parts of the nails into the drilled holes, assembling the wood structure nondestructive testing equipment, and adjusting the mounting positions of the force application frames to enable the nail positioners to be sleeved on the nails and coincide with the axes of the nails;
s2: the force application device applies downward pressure, the nail pressing head moves downwards until the bottom surface of the nail pressing head contacts with the upper surface of the nail, the force sensor obtains monitoring data in an initial state, the nail pressing head is continuously pressed down until the nail is pressed down to a designated depth, the force sensor obtains the monitoring data at the moment, and the monitoring data are transmitted to the data acquisition and transmission device; the force application device applies upward tension, and the nail pressing head drives the nail positioner to lift upwards until the nails are pulled out of the wood component to be detected;
s3: the data acquisition and transmission device calculates the nail-holding force of the wood component to be detected according to the monitoring data, and the calculation formula of the nail-holding force is as follows:
；
wherein P is max The unit N is the maximum pulling force detected when the nail is pulled out;
m 1 the mass of the nail positioner is kg;
m 2 the unit is kg of the mass of the nailing head;
g is gravity acceleration, and the unit is N/kg;
f is the nail-holding force of the wood component to be measured, and the unit is N/mm;
l is the depth of the nails, which is measured by the wood component to be nailed, and the unit is mm;
s4: when the nails are round steel nails, the density of the wood component to be measured is calculated as follows:
；
wherein ρ is the density of the wood member to be measured, and the unit is g/cm 3 ；
k 1 Adjusting the coefficient for the density;
f is the nail-holding force of the wood component to be measured, and the unit is N/mm;
w is the absolute water content of the wood component to be measured, and the units are expressed in percentage;
the flexural strength of the wood member to be measured was calculated as follows:
；
wherein,the bending strength of the wood component to be tested is expressed in MPa;
k 2 the bending strength adjustment coefficient is used;
f is the nail-holding force of the wood component to be measured, and the unit is N/mm;
w is the absolute water content of the wood component to be measured, and the units are expressed in percentage.
8. A nondestructive inspection method for a wooden structure using the nondestructive inspection apparatus for a wooden structure according to any one of claims 1 to 6, characterized by comprising the steps of:
s1: pre-drilling holes at the positions of the wood component to be detected, which are required to be detected by the nail holding force, vertically inserting the tip parts of the nails into the drilled holes, assembling the wood structure nondestructive testing equipment, and adjusting the mounting positions of the force application frames to enable the nail positioners to be sleeved on the nails and coincide with the axes of the nails;
s2: the force application device applies downward pressure, the nail pressing head moves downwards until the bottom surface of the nail pressing head contacts with the upper surface of the nail, the force sensor obtains monitoring data in an initial state, the nail pressing head is continuously pressed down until the nail is pressed down to a designated depth, the force sensor obtains the monitoring data at the moment, and the monitoring data are transmitted to the data acquisition and transmission device; the force application device applies upward tension, and the nail pressing head drives the nail positioner to lift upwards until the nails are pulled out of the wood component to be detected;
s3: the data acquisition and transmission device calculates the nail-holding force of the wood component to be detected according to the monitoring data, and the calculation formula of the nail-holding force is as follows:
；
wherein P is max The unit N is the maximum pulling force detected when the nail is pulled out;
m 1 the mass of the nail positioner is kg;
m 2 the unit is kg of the mass of the nailing head;
g is gravity acceleration, and the unit is N/kg;
f is the nail-holding force of the wood component to be measured, and the unit is N/mm;
l is the depth of the nails, which is measured by the wood component to be nailed, and the unit is mm;
s4: when the nails are screws, the density of the wood component to be measured is calculated as follows;
；
wherein ρ is the density of the wood member to be measured, and the unit is g/cm 3 ；
k 1 Adjusting the coefficient for the density;
f is the nail-holding force of the wood component to be measured, and the unit is N/mm;
w is the absolute water content of the wood component to be measured, and the units are expressed in percentage;
the flexural strength of the wood member to be measured was calculated as follows:
；
wherein,the bending strength of the wood component to be tested is expressed in MPa;
k 2 the bending strength adjustment coefficient is used;
f is the nail-holding force of the wood component to be measured, and the unit is N/mm;
w is the absolute water content of the wood component to be measured, and the units are expressed in percentage.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311615471.9A CN117309213B (en) | 2023-11-30 | 2023-11-30 | Nondestructive testing equipment and method for wood structure |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311615471.9A CN117309213B (en) | 2023-11-30 | 2023-11-30 | Nondestructive testing equipment and method for wood structure |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN117309213A CN117309213A (en) | 2023-12-29 |
| CN117309213B true CN117309213B (en) | 2024-02-09 |
Family
ID=89286982
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311615471.9A Active CN117309213B (en) | 2023-11-30 | 2023-11-30 | Nondestructive testing equipment and method for wood structure |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117309213B (en) |
Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7089803B1 (en) * | 2005-10-28 | 2006-08-15 | Huber Engineered Woods Llc | Panel performance testing system |
| JP2010160077A (en) * | 2009-01-08 | 2010-07-22 | Building Research Institute | Portable pull-out tester |
| CN103884456A (en) * | 2014-04-04 | 2014-06-25 | 南京林业大学 | Nail-holding ability measurement device for wood-structure building component |
| CN203981325U (en) * | 2014-06-18 | 2014-12-03 | 巨石集团有限公司 | Nail-holding power pick-up unit |
| CN110726586A (en) * | 2019-11-26 | 2020-01-24 | 上海市建筑科学研究院有限公司 | On-site micro-damage sampling detection method for wood strength |
| CN110864837A (en) * | 2019-11-22 | 2020-03-06 | 四川省建筑科学研究院有限公司 | Steel nail anchoring force detection device and use method thereof |
| CN112345145A (en) * | 2020-11-24 | 2021-02-09 | 宁波辣生科技有限公司 | Wood board nail-holding power detection device |
| CN112461679A (en) * | 2020-01-15 | 2021-03-09 | 程彦 | Wood structure component decay degree torsion method in-situ detection device |
| CN212904637U (en) * | 2020-08-12 | 2021-04-06 | 上海建工集团股份有限公司 | Timber moisture content test probe |
| CN112816322A (en) * | 2020-12-28 | 2021-05-18 | 同济大学 | Wood transverse grain tensile strength detection device and field test method |
| WO2022142072A1 (en) * | 2020-10-22 | 2022-07-07 | 蔡文佳 | Mounting nail head, mounting nail, mounting member and mounting method therefor |
-
2023
- 2023-11-30 CN CN202311615471.9A patent/CN117309213B/en active Active
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7089803B1 (en) * | 2005-10-28 | 2006-08-15 | Huber Engineered Woods Llc | Panel performance testing system |
| JP2010160077A (en) * | 2009-01-08 | 2010-07-22 | Building Research Institute | Portable pull-out tester |
| CN103884456A (en) * | 2014-04-04 | 2014-06-25 | 南京林业大学 | Nail-holding ability measurement device for wood-structure building component |
| CN203981325U (en) * | 2014-06-18 | 2014-12-03 | 巨石集团有限公司 | Nail-holding power pick-up unit |
| CN110864837A (en) * | 2019-11-22 | 2020-03-06 | 四川省建筑科学研究院有限公司 | Steel nail anchoring force detection device and use method thereof |
| CN110726586A (en) * | 2019-11-26 | 2020-01-24 | 上海市建筑科学研究院有限公司 | On-site micro-damage sampling detection method for wood strength |
| CN112461679A (en) * | 2020-01-15 | 2021-03-09 | 程彦 | Wood structure component decay degree torsion method in-situ detection device |
| CN212904637U (en) * | 2020-08-12 | 2021-04-06 | 上海建工集团股份有限公司 | Timber moisture content test probe |
| WO2022142072A1 (en) * | 2020-10-22 | 2022-07-07 | 蔡文佳 | Mounting nail head, mounting nail, mounting member and mounting method therefor |
| CN112345145A (en) * | 2020-11-24 | 2021-02-09 | 宁波辣生科技有限公司 | Wood board nail-holding power detection device |
| CN112816322A (en) * | 2020-12-28 | 2021-05-18 | 同济大学 | Wood transverse grain tensile strength detection device and field test method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN117309213A (en) | 2023-12-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109406340B (en) | Device and method for testing grouting compactness of sleeve connecting structure by hammering pre-compression | |
| Tannert et al. | In situ assessment of structural timber using semi-destructive techniques | |
| US11486806B2 (en) | Automated profiling of the hardness of wood | |
| JP4607977B2 (en) | Soil sampling device | |
| CN102338717A (en) | Equipment and method for detecting performance of artificial board | |
| CN117309213B (en) | Nondestructive testing equipment and method for wood structure | |
| CN202041424U (en) | Detection device for performance of artificial board | |
| US10837870B2 (en) | Non-destructive apparatus, system and method for determining pull-out capacity of friction nails | |
| JP4927883B2 (en) | Portable pull-out tester | |
| Kasal et al. | Semi-destructive methods for evaluation of timber structures | |
| CN104390868A (en) | Fast detector for strength of mortar and use method thereof | |
| KR101788618B1 (en) | model prestress structures test methods | |
| KR101790057B1 (en) | A testing apparatus of model prestress structures | |
| US5067353A (en) | Roof sheathing test system | |
| CN106839960A (en) | Nondestructive testing method for size and internal defects of mortise and tenon joint of wood structure | |
| JP2010008258A (en) | Strength evaluation method of wood and repair diagnosing method of structure | |
| CN115728467A (en) | Pressure-rotating penetration sounding equipment and method for measuring rock-soil body parameters | |
| Seymour et al. | A practical method of measuring shotcrete adhesion strength | |
| CN204346850U (en) | A kind of mortar strength fast detector | |
| CN207946304U (en) | One kind being used for building exterior wall material tensile strength detection device | |
| Ivanchev | Research on concrete compressive strength in existing reinforced concrete elements with Schmidt hammer, ultrasonic pulse velocity method and destructive testing of cores | |
| KR101248279B1 (en) | Fracture toughness testing machine | |
| RU2793557C1 (en) | Method for control of compressive strength of hardened masonry solutions | |
| CN219891011U (en) | Horizontal penetrating type mortar strength detector calibrating device | |
| CN220394484U (en) | Novel counter force device of static cone penetration tester |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |