193 results about "Compressive test" patented technology

The invention discloses a coal rock mass creep disturbance test method, which belongs to the technical field of rock mechanics and engineering, and comprises the following steps: S1, carrying out a conventional compression test, and determining creep and disturbance test parameters; s2, carrying out a graded loading creep test; s3, carrying out a creep disturbance test; applying a disturbance load to the test piece according to creep and disturbance test parameters, and monitoring stress, strain, damage evolution and instability failure characteristics of the test piece under the action of dynamic load disturbance; judging the next test process according to the deformation evolution rule of the test piece after each disturbance; and S4, determining a strength limit neighborhood of the test piece under the action of creep and disturbance according to a test result. According to the method, key information such as the deformation rule, the instability failure characteristic and the strength limit of the coal rock mass can be disclosed, then the damage evolution rule, the strength limit and the instability mechanism of the coal rock mass under the creep action and the dynamic load disturbance action are researched, and scientific basis and technical support are provided for stability prediction and control of engineering rock mass in engineering practice.

The invention relates to the technical field of composite material mechanical property detection, in particular to a composite material plate compression test clamping device, which comprises a fixed seat, and a clamping mechanism, a power device and a loading assembly which are arranged on the fixed seat, the clamping mechanism comprises a first clamping assembly and a second clamping assembly which are oppositely arranged, the first clamping assembly is driven by a power device to move towards the second clamping assembly, the sample plate is clamped and fixed from the two sides of the sample plate, and the stability of uniform clamping of the sample plate is ensured. The first movable clamping plate and the second movable clamping plate are connected with the loading assembly and are driven by the loading assembly to move towards the first fixed clamping plate and the second fixed clamping plate respectively. A clamped and fixed sample plate is vertically loaded by independently controlling a loading assembly, the loading assembly comprises a downward pressing seat and a loading rod arranged on the downward pressing seat, a ball head part of the loading rod is rotationally connected with the downward pressing seat, a ball joint can compensate the installation angle deviation of the sample, and it is ensured that a compression load acts on the center of the sample plate in the vertical direction all the time.

The invention provides a simulation material for a mechanical test of a press-fitting explosive, which is prepared from the following raw materials in parts by weight: 65.5% of ammonium sulfate, 27%-33% of aluminum powder, 1.5%-4% of microcrystalline wax, 1%-2% of butadiene rubber and 0.2%-0.8% of graphite. The compressive strength and the tensile strength of a grain formed by pressing the simulation material for the mechanical test of the pressed explosive are basically consistent with those of a grain formed by pressing a polyblack aluminin-2 (JHL-2) explosive, the change trend and the change limit of the strength in the mechanical test process can be truly reflected, and effective reference data are provided for mechanical property evaluation; relatively real and reasonable model parameters are provided for the digital design of the mechanical property of the press-fitting explosive; in an aging test, a tensile test, a mechanical compression test and a dynamic Brazilian test, the simulation material for the press-fitting explosive mechanical test can be prevented from being in contact with energetic explosive components, so that the safety of the test is improved, and the potential safety hazard is reduced.

The invention discloses a test device for measuring the compression strength of a composite material plate, which comprises an upper box body and a lower box body, a guide column is arranged between the upper box body and the lower box body, an upper clamping assembly is arranged at the lower end of the upper box body, a lower clamping assembly is arranged at the upper end of the lower box body, and the upper clamping assembly and the lower clamping assembly have the same structure and opposite installation directions. The upper clamping assembly or the lower clamping assembly comprises two wedge-shaped clamping block units which are oppositely arranged, and the end part of the test piece is clamped between the two wedge-shaped clamping block units. The invention also discloses a test method for measuring the compression strength of the composite material plate. The test device can stably work for a long time in high and low temperature environments, meets the test requirements of a compression test, adopts a split design, is rapid in clamping, can effectively resist bending and torsional deformation, improves the test efficiency and accuracy, keeps reliable clamping all the time in the test process, and is simple in structure and convenient to operate. And the problem of clamping failure caused by thermal expansion and cold contraction is effectively solved.

The invention relates to the technical field of soft rock simulation tests, and discloses a soft rock stress monitoring simulation system which comprises a base and a mounting frame fixed to the top side of the base, a workbench is arranged in the mounting frame, a connecting assembly used for being connected with the mounting frame is arranged on the workbench, and a carrier plate is slidably connected to the interior of the workbench; a pressure sensor is fixed to the inner wall of the workbench, a pressure block is fixed to the sensing end of the pressure sensor, a containing groove is formed in the side, close to the pressure sensor, of the carrier plate, the pressure block slides in the containing groove, and a protective shell sliding in the mounting frame is arranged above the carrier plate. According to the invention, a compression test can be carried out on the test block, so that the mechanical parameters of the soft rock can be measured, basic data can be provided for stress monitoring, the working performance is high, an experimenter can be helped to carry the test piece into the device, the use is convenient, the compressed test piece can be protected, and the safety performance is high.

The invention discloses a solid filling material compression test device, and relates to the technical field of compression tests, the solid filling material compression test device comprises a rack, a box body is arranged on the rack, a pressing block is arranged above the box body, the pressing block and the box body are in compression fit, and control assemblies are arranged on the two sides of the box body. According to the solid filling material compression test device, the box body is knocked back and forth through the first knocking rod, and meanwhile, the side wall of the box body is knocked back and forth through the second knocking rod, so that a solid filling material fed into the box body can be more uniformly distributed at the bottom of the box body; according to the invention, local accumulation or non-uniform distribution of the material caused by factors such as gravity and a falling mode in a throwing process is avoided, a more uniform initial material state is provided for a subsequent compression test, a test result is ensured to more accurately reflect the compression performance of the material under an ideal distribution condition, and material particles can be rearranged and closely contacted through knocking vibration, so that the compression performance of the material is improved. Gaps are reduced, so that the material reaches a denser state before a compression test, and the accuracy and the reliability of test data are improved.

The present invention relates to a compression test device for a composite laminate with a large length-thickness ratio, belonging to the technical field of composite material testing. It can achieve that the two-side boundaries are kept in a simply supported constraint throughout the compression test process, and the simply supported condition is not easily changed at the moment of failure. The flatness of the loading plane on the length and width surfaces of the plate specimen is also adjusted through a grid device. The device includes: two groups of side supports are respectively arranged at both ends of the bottom installation component, and the specimen is vertically arranged between the two groups of side supports; two groups of bottom constraint plates, four simply supported constraint plates and two groups of out-of-plane adjustable grids are respectively arranged on both sides of the plate-shaped specimen, and the two groups of bottom constraint plates are respectively arranged at the bottom of the plate-shaped specimen, and the four simply supported constraint plates are respectively arranged in pairs at the left and right ends of the plate-shaped specimen; the bottom constraint plates are connected to the bottom installation component, and the simply supported constraint plates are connected to the corresponding side supports; two groups of end constraint plates are respectively arranged on both sides of the top of the plate-shaped specimen and are fixedly connected to the end loading plates arranged thereon, and the end loading plates are connected to the test loading equipment.

The present invention provides a carton strength testing device, which relates to the technical field of carton strength testing, and comprises: a compression test bench, a compression test press is installed above the compression test bench, a carton placing table is movably connected above the compression test bench, water mist is applied to the inside of the carton through a humidifying nozzle to increase the humidity inside the carton, and the scene of the carton storing wet objects for a long time in actual application is simulated, so that the detection method is closer to the actual application, and the performance detection function of the inner waterproof layer of the carton is realized, and the problem that in the sealing test of the waterproof layer on the inner surface of the carton, the humidification process of the carton is too radical through the detection method of injecting water into the carton, the waterproof layer of the carton is prone to leakage under the action of water pressure, or leakage through the edge of the waterproof layer, which is inconsistent with the actual application environment of the waterproof carton, and the waterproof layer of the carton cannot be slightly humidified for a long time to simulate the environment of storing and transporting wet objects in the carton in actual application.

The utility model belongs to the technical field of composite material structure test, and discloses an axial compression test fixture, which comprises a base, two side support pieces, a first clamping assembly and an anti-instability assembly, the two side support pieces are oppositely arranged on the base, a composite material is arranged between the two side support pieces, and the anti-instability assembly comprises two first anti-instability pieces and two second anti-instability pieces. Each first anti-instability piece comprises two separated first abutting parts, the distance between the two first abutting parts is larger than the damage range of the side face of the composite material, the two first anti-instability pieces are arranged on the two sides, in the second direction, of the composite material and close to the impacted side face of the composite material, and the second anti-instability pieces correspond to the first anti-instability pieces in a spaced mode; the first anti-instability piece and the second anti-instability piece are fixed to the two side supporting pieces respectively. The first clamping assembly can clamp the top of the composite material. The axial compression test clamp can be used for clamping a composite material subjected to side impact, and the problem that the accuracy of compression test data obtained after the composite material is subjected to side impact is not high is solved.

The utility model relates to the technical field of compression resistance detection, in particular to an electrical equipment compression resistance detection device, which comprises a bottom plate, a clamping mechanism arranged above the bottom plate, and a detection mechanism used for performing compression resistance detection on an electrical workpiece and positioned above the clamping mechanism, the detection mechanism comprises a detection assembly and a driving assembly used for driving the detection assembly to move up and down, a pressing plate is installed below the oil cylinder in a sliding mode, and auxiliary assemblies used for conducting auxiliary clamping on the electrical workpiece during compression resistance detection are arranged on the two sides of the pressing plate. The device has the beneficial effects that the larger the force applied to equipment by pressing the pressing plate downwards is, the larger the clamping force applied to the equipment by the auxiliary assembly is, the offset phenomenon of the equipment under the condition that the larger the pressure applied to the equipment is is avoided, the offset of a force application point of the pressing plate to the equipment is avoided, the uniformity of force application is ensured, and the service life of the equipment is prolonged. And certain interference on compressive test detection is avoided, so that the accuracy of compressive test data is improved.

The invention belongs to the technical field of structural material design, and particularly relates to a method for determining an allowable value of an aviation composite material structure. The method mainly comprises the following steps: correcting a tension-compression strength allowable value according to a first ratio of the breaking strength of a single-side lap joint tension-compression test to the breaking strength of a single composite material tension-compression test; a plurality of second ratios of the shear failure strength of the composite materials with different thicknesses to the shear failure strength of a single composite material are formed through bonding, and the shear strength allowable value is corrected; correcting the allowable value of the tensile strength according to a plurality of third ratios of the tensile breaking strength of the composite materials with different thicknesses formed by screw connection to the tensile breaking strength of a single composite material; and correcting the allowable value of the compression strength according to a plurality of fourth ratios of the compression breaking strength of the composite materials with different thicknesses after impact breaking to the compression breaking strength of a single composite material. A basis is provided for relatively reasonable, safe and effective design of the composite material structure.

The present invention relates to the technical field of compression testing, and proposes a motor housing compression test bench, including a test bench, a bottom plate fixedly installed at the bottom of the test bench, a connecting structure slidably sleeved on the left and right sides of the test bench, a first electric push rod installed on both sides of the test bench, the first electric push rod is fixedly connected to the connecting structure, a clamping structure is fixedly installed in the middle of the connecting structure, and an extrusion structure is installed on both the front and rear sides of the test bench. By installing two symmetrical extrusion structures on the front and rear sides of the test bench, and setting a rotating shaft on the outer side of the extrusion structure, when the rotating shaft rotates, the eccentric block squeezes the connecting block toward the motor housing, so that the first pressing block at the top of the connecting block contacts the motor housing, so that the motor housing is subjected to compression testing, and at the same time, the test probe continues to monitor the inner wall of the motor housing, and detects and records the deformation of the motor housing when it is under pressure, so as to ensure the accuracy of the compression test of the motor housing.

The invention discloses compression resistance testing equipment for a mirror surface, and belongs to the technical field of optical lens pressure detection equipment. The pressure detection mechanism comprises a hydraulic cylinder arranged on the frame, a hydraulic rod at the bottom end of the hydraulic cylinder extends to the pressing plate, and the pressure detection mechanism is used for pressing and detecting the mirror surface; and the supporting mechanism comprises a first triangular plate arranged at the notch of the workbench, an elastic telescopic part is installed at the top end of the first triangular plate, and fixing rods installed on the first triangular plate are arranged on the periphery of the edge of the outer wall of the elastic telescopic part. The clamping mechanism can solve the problems that an existing clamping mechanism conducts limiting in a two-side or four-side clamping mode, but does not conduct all-directional clamping limiting on a lens, and when a pressing point is located at the edge of the lens, the clamping mechanism is prone to being separated from the lens in a traditional clamping mode, and the clamping mechanism cannot conduct clamping limiting on the lens. And the safety of the device is not improved.

The present invention discloses a method for simultaneously characterizing the mechanical properties and microstructure of a single granular body. This method is suitable for simultaneously characterizing the mechanical properties and microstructure of explosive granular bodies and other energetic material crystals or granular materials. The test process includes six steps: sample preparation, sample installation, parameter adjustment of a mechanical-optical microscope combined test system, mechanical-optical real-time monitoring testing, analysis of the granular body's compression performance and optical images, and simultaneous characterization of its mechanical properties and microstructure. A dedicated compression test fixture is designed, and an evaluation basis for the simultaneous characterization of mechanical properties and microstructure is proposed. The present invention monitors the deformation characteristics of a single granular body during compression. The test process is observable, and the test conditions are more scientific and reasonable, improving the accuracy of the characterization. The method is also simple to operate and requires less experimental personnel.

Provided are composite particles having low electrical resistance. The composite particles contain an electrode active material, a conductive material, and a binder material. When the composite particles are compressed at a load rate of 0.04 mN / sec by a minute compression testing machine, the test force at the failure point is 0.40 mN or more and 1.60 mN or less.

This invention proposes a simulation material for mechanical testing of press-loaded explosives, which, by weight, is made from the following raw materials: 65.5% ammonium sulfate, 27%–33% aluminum powder, 1.5%–4% microcrystalline wax, 1%–2% butadiene rubber, and 0.2%–0.8% graphite. The compressive and tensile strengths of the explosive charge formed by this simulation material are essentially consistent with those of the charge charge formed from polyaluminum black-2 (JHL-2) explosive. It can realistically reflect the trend and limit of strength changes during mechanical testing, and provides effective reference data for mechanical performance evaluation. It also provides relatively realistic and reasonable model parameters for the digital design of the mechanical properties of press-loaded explosives. In aging tests, tensile tests, mechanical compression tests, and dynamic Brazilian tests, using this simulation material avoids contact with energetic explosive components, increasing test safety and reducing safety hazards.

The utility model discloses an endurance test device for a dust cover. The endurance test device comprises a rack, a first telescopic device and a second telescopic device, a placing plate is arranged in the middle of the rack, and the first telescopic device and the second telescopic device are mounted above and below the placing plate respectively; the second telescopic device is suitable for upwards penetrating through the placing plate so as to be used for positioning and sleeving the dustproof cover to be tested; and the first telescopic device is suitable for pressing the top of the positioned dust cover downwards and driving the dust cover to be subjected to repeated compression deformation relative to the placing plate through reciprocating motion. The dustproof cover testing device has the beneficial effects that compared with an existing dustproof cover testing device, the dustproof cover testing device can effectively test the dustproof cover in the folding resistance aspect. And a high-strength compression test can be performed on the dust cover through the first telescopic device and the second telescopic device, so that whether the dust cover is folded or not is subjected to a high-strength test.

The invention discloses a compressive strength testing device for ultra-light and high-strength mullite corundum lightweight bricks, relates to the technical field of mullite lightweight brick compressive testing, and is mainly aimed at completing accurate zoning of various stages in the process of compressive strength testing of lightweight brick masonry, that is, the phenomenon that the stress detection result of lightweight brick masonry is inaccurate due to insufficient or excessive pressure application; in the invention, on the premise of accurately knowing the stress damaged position of lightweight brick masonry and the various stages of crack generation and crushing, the compressive test is completed through automatic pressurizing action, avoiding the situation that the downtime is too long due to manual adjustment of the pressure size and the crack generation time period and the crushing time point are unclear, thereby facilitating accurate grading of the compressive strength of lightweight brick masonry, and then accurately controlling the various stages of the pressurizing action with the aid of a control system, so that the lightweight brick masonry can obtain accurate zoning of various stages in the process of compressive strength testing.

The invention provides an energy-containing fragment Hopkinson compression test protection and product recovery device, which comprises a protection cover, and the side wall of the protection cover is provided with an incident bar mounting hole and a transmission bar mounting hole. An incident rod is arranged in the incident rod mounting hole in the radial direction, an incident rod gasket is arranged at the end, located in the protection cover, of the incident rod, an energy-containing fragment sample is arranged at the other end of the incident rod gasket, and a transmission rod gasket is arranged at the other end of the energy-containing fragment sample. A transmission rod is arranged in the transmission rod mounting hole; and a transmission rod gasket is arranged at the end part of the transmission rod in the protective cover. A recovery cover is arranged at the bottom of the protection cover, a recovery cover through hole is formed in the bottom of the recovery cover, and a recovery box is arranged at the bottom of the recovery cover through hole. According to the device, the protection cover and the recovery cover are adopted, so that product fragments can be effectively prevented from splashing to damage personnel and other equipment, the recovery box is adopted to completely and efficiently recover the product fragments, and the safety and convenience of the test are effectively improved.

The invention relates to a metal material strain rate effect measurement method based on multiple stress relaxation, which comprises the following steps: carrying out a standard quasi-static stretching or compression test on a material sample at a constant strain rate to obtain a stress-strain curve; analyzing a strain range according to a stress-strain curve, and determining a stress relaxation frequency N to be developed and a corresponding relaxation strain value sequence epsilon i, i = 1... N; a material sample is taken to be subjected to a tensile or compression test at a set strain rate, stress relaxation lasts for relaxation time delta t when the strain sequentially reaches values in each relaxation strain value sequence, and after each stress relaxation, the tensile or compression test is performed according to the set strain rate; obtaining a stress-plastic strain rate curve corresponding to each relaxation strain epsilon i; and obtaining a stress-strain curve corresponding to each strain rate. Stress-strain curves corresponding to different plastic strain rates in a quasi-static range can be obtained through a single sample.

The invention discloses a strength detection device which comprises a compression testing machine, and the compression testing machine is sleeved with a rotatable lantern ring. The sleeve ring is connected with an adjustable assembly, the adjusting assembly is connected with a moving assembly, the adjusting assembly is provided with a clamping assembly, and the clamping assembly is connected with the moving assembly; the lantern ring is connected with a pushing assembly. The compression testing machine is connected with a placing assembly, and the placing assembly is connected with a shielding assembly; a fence is fixedly connected to the compression testing machine and is positioned on one side of the pushing assembly. According to the device, test pieces can be moved from the guide plate to the test bed, workers do not need to place the test pieces one by one, work of the workers is reduced, meanwhile, large-scale detection of the workers is facilitated, work of the workers is further facilitated, the work efficiency of the workers is indirectly improved, and the work efficiency of the workers is improved. And the practicability of the device is further improved.

The utility model relates to the field of geological science, and discloses a frozen soil melting compression tester which comprises an operation table, a plurality of testers are fixedly connected to the top of the operation table, a control cabinet is fixedly connected to the right side of the operation table, a water flow meter is arranged on the upper portion of the front side of the control cabinet, and an air flow meter is arranged on the upper portion of the front side of the control cabinet. The lower part of the front side of the control cabinet is provided with a water level gauge, the control cabinet is provided with a computer, the top of the tester is fixedly connected with a reaction frame, the front side of the reaction frame is provided with a displacement meter, the interior of the reaction frame is in threaded connection with a puller screw, and the bottom end of the puller screw is provided with a heating pressure transfer plate. According to the utility model, through the cooperation of the tester, the heating and pressure transmitting plate, the heat preservation jacket, the pressurizing plate, the water container and other structures, errors caused by manual operation are reduced, the experiment precision and efficiency are improved, meanwhile, the melting environment is simulated, experiment data under real conditions are provided, and the reliability and practicability of research results are enhanced.

The invention provides a portable multifunctional rock mechanics testing machine and method, and relates to the technical field of rock mechanics tests. According to the portable multifunctional rock mechanics testing machine, an expansion test assembly, a uniaxial compression test assembly, a point load test assembly, an indentation test assembly or a compression-shear test assembly are selectively arranged between a telescopic rod of a loading oil cylinder and / or a force transducer. The testing machine disclosed by the invention is simple and light in structure, and can be conveniently carried to an engineering site to carry out a rock mechanical test, so that on-site loading and data acquisition of a rock sample are realized; the tester can accurately control stress and strain conditions and can realize stable and uniform loading and unloading on site so as to obtain a reliable test result; the testing machine integrates multifunctional testing, and different testing assemblies are matched with an expansion test, a uniaxial compression test, a point load test, an indentation test or a compression-shear test, so that multi-parameter testing is realized aiming at different rock sample conditions.

The embodiment of the present invention provides a solid filling material compression test device and method that can simulate the filling step and lateral pressure, and relates to the technical field of mechanical property testing of solid filling materials. The device includes: a model box, on the bottom plate, a first side plate, a second side plate, a third side plate and a fourth side plate are arranged around the bottom plate, the first side plate is opposite to the third side plate, and is used to simulate the upper and lower drifts of the coal mining working face, respectively, the second side plate is opposite to the fourth side plate, and is used to simulate the open eye coal wall, a pressure component is arranged on the fourth side plate, and under the push of the pressure component, the fourth side plate moves toward the second side plate, and a plurality of discharge plates arranged parallel to the fourth side plate are arranged on the top of the first side plate and the third side plate, and the discharge plate has a filling port for filling into the filling space. The experimental results obtained based on the experimental device and method can more accurately reflect the mechanical properties of solid filling materials in actual filling mining.

The utility model provides a kind of cord fabric pressure test device, the lower part of the clamp is provided with compression testing machine platform, the upper part of the clamp is provided with down device, the clamp includes clamp main body, the lower part of the clamp main body is provided with connecting flange, connecting pin passes from the inside of connecting flange, the clamp main body is surrounded with cord fabric, large clamp piece is installed in the both sides of the cord fabric, the large clamp piece is fixed in the clamp main body with cord fabric, small clamp piece is installed in the both sides of the upper side of the cord fabric, the small clamp piece is compacted in the upper side of cord fabric, spring is installed between the large clamp piece and clamp main body, the top of the clamp main body is provided with pressure head, connecting pin passes from the top of pressure head;The utility model can make contrastive analysis to data by a series of standardization test to cord fabric, prevent the risk of structural failure in advance, to reduce the risk of tire burst.

The invention provides a characterization method and a characterization device for time-varying characteristics of mechanical properties of a composite material in a curing process. The characterization method comprises the following steps: step 1, obtaining reaction enthalpy released by complete curing of a to-be-detected prepreg with unit mass; 2, obtaining multiple groups of compression samples and DSC samples; 3, curing the compression sample and the DSC sample at the same time by adopting a composite material repairing instrument, terminating the curing process of each group of samples at different preset time, and recording the temperature T of each group of samples at the curing termination; step 4, for each group of samples, measuring the compression modulus of the compressed sample at the corresponding temperature T after the step 3 by using a mechanical testing machine, and obtaining the curing degree of the DSC sample after the step 3; 5, according to the multiple sets of curing degrees and compression moduli, the moduli of the resin under the different curing degrees are obtained through backstepping by means of the self-consistent field mesomechanics model, and then the time-varying characteristics of the mechanical property of the composite material in the curing process can be obtained. The characteristics that the composite material repairing instrument can safely and controllably terminate the composite material curing process at any time, the mechanical property of the composite material in the thickness direction, the compression test is easy to implement and the like are fully combined, and the problems that composite material mechanical samples are difficult to machine and mechanical properties are difficult to measure under different curing degrees and different temperatures are solved; accurate measurement of the time-varying characteristic of the mechanical property of the composite material is realized.

The utility model discloses a composite material compression test piece positioning tool which comprises a positioning block assembly, the positioning block assembly comprises an upper positioning block and a lower positioning block, and opposite plate surfaces of the upper positioning block and the lower positioning block are respectively provided with positioning raised lines corresponding to an upper notch and a lower notch; reinforcing sheet placing areas are respectively formed on two sides, corresponding to the positioning raised lines, of the upper positioning block and the lower positioning block; the baffle assembly comprises a left side baffle and a right side baffle, and the left side baffle and the right side baffle are arranged on the left side and the right side of the positioning block assembly respectively and connected with the upper positioning block and the lower positioning block through fasteners respectively; the positioning pin assembly comprises a plurality of positioning pins, a plurality of vertically corresponding positioning grooves are formed in the front ends and the rear ends of the upper positioning block and the lower positioning block respectively, and the positioning pins are inserted into the corresponding positioning grooves. According to the utility model, the symmetry of two reinforcing sheets is ensured, the stability of the reinforcing sheets in the positioning process is ensured, and the precision of a test piece is improved.

The utility model discloses an expandable compression testing machine, and relates to the technical field of compression testing machines. The device comprises a bottom plate, a compression mechanism is arranged on the bottom plate, the compression mechanism comprises a [-shaped frame fixedly connected to the top of the bottom plate, an electric push rod is fixedly connected to the top of the [-shaped frame, and an output shaft of the electric push rod extends into the [-shaped frame and is in sliding connection with the [-shaped frame. Accurate control over the moving path of the hold-down device in the compression process can be achieved through the compression mechanism, the possibility that the hold-down device deviates in the operation process is fundamentally eradicated, the accurate control enables the hold-down device to be kept highly stable in the moving process, and therefore when pressure is applied to a sample piece, the sample piece is not prone to deviation. The pressure can be ensured to uniformly and accurately act on the sample piece, the test error caused by non-uniform pressure or deviation is effectively avoided, the reliability and precision of the test result are remarkably improved, and more valuable data support is provided for scientific research and production.

The invention relates to a set of mold for preparing a specific-density to-be-tested sample in a triaxial compression test, and belongs to the field of geotechnical engineering sample devices.The mold comprises a pressing and clamping assembly, a forming assembly is arranged in the pressing and clamping assembly, and a pressure applying assembly is slidably connected to the pressing and clamping assembly; the bottom end of the pressure applying assembly extends into the forming assembly to apply pressure to a sample located in the forming assembly, a functional ring is arranged at the end of the pressing and clamping assembly, and the functional ring abuts against the end of the pressing and clamping assembly. According to the invention, the operation process is simplified, the efficiency and safety of taking out the sample are improved, and the preparation work of the sample can be completed more efficiently and accurately, so that the quality and efficiency of a triaxial compression test are improved.

To provide a base material for packaging which is excellent in cushioning property, a base material for packaging which is excellent in flexibility, a material for packaging using the base materials for packaging, and a method for manufacturing a material for packaging.SOLUTION: There are provided a base material for packaging containing natural fibers in which a basis weight is 18 g / m2 or more and 50 g / m2 or less, and compressive strength (one base material to be measured, deformation rate of 0.02 mm / sec, initial compression load of 50 gf / cm2, and maximum compressive load of 300 gf / cm2) that is measured using a KES-G5 compression testing machine is 1.5 or less; a material for packaging which has a heat seal layer on at least one surface of the base material for packaging, and heat seal strength when being heat sealed at a temperature of 130°C and a pressure of 1.0 kgf / cm2 for 1 second, and being peeled at a tension rate of 30 mm / min by a T type of 0.5 N / 15 mm or more; and a method for manufacturing a material for packaging which coats a coating liquid containing a thermoplastic resin onto the base material for packaging by a gravure method or a flexographic method, and thereby forms a heat seal layer.SELECTED DRAWING: Figure 1