1784results about How to "Reduce stress concentration" patented technology

The invention discloses a thermal deformation prediction and optimization method and system in metal plastic composite product processing, and the method comprises the steps: building a composite product geometric model according to the material characteristics and preset boundary conditions of a composite product; according to the geometric model of the composite product, a finite element analysis method is used, a preset time step length and a nonlinear solver are selected for coupling solving of a thermal field and a mechanical field; the change data of the temperature field and the stress field along with time and thermomechanical circulation are analyzed through simulation, accumulated deformation and interface stress data of the material in circulation of the preset number of times are monitored, and a simulation prediction result is generated; and according to the simulation prediction result, the heating and cooling rate and the mold loading path are optimized. The thermal deformation prediction and optimization method in metal plastic composite product processing can be used for solving based on multi-physics field coupling in combination with a nonlinear finite element.

The invention relates to the technical field of composite materials, in particular to high-thermal-conductivity organic silicon resin and a preparation process thereof. The invention relates to a preparation process of organic silicon resin with high thermal conductivity. The preparation process comprises the following steps: adding a nano filler with high thermal conductivity into a silane coupling agent for surface modification; adding the modified filler into an organic silicon resin matrix, mixing, adding a cross-linking agent, and carrying out shearing treatment; pouring the mixed solution into a mold, and treating in a strong electromagnetic field; placing the mold in a vacuum filling device to remove bubbles; and putting the mixture into a drying oven for crosslinking and curing to obtain the high-thermal-conductivity organic silicon resin. Through the high-speed shearing effect, the filler is arranged in the matrix in the shearing direction to form a continuous heat conduction path, the filler is regularly guided through a strong electromagnetic field to form a continuous heat conduction channel, bubbles in the material are removed under the vacuum condition, it is ensured that organic silicon resin is filled into pores of a filler framework, and the heat conduction performance of the filler is improved. The uniformity and integrity of the material are improved, and the interface thermal resistance is reduced, so that the heat-conducting property is improved.

The utility model discloses an extrusion cooling device for MPP cable protection tube processing, which belongs to the technical field of MPP cable protection tube processing, and is characterized by comprising a base, the top of the base is fixedly connected with a cooling assembly, the top of the base is fixedly connected with a spraying assembly, the cooling assembly comprises a supporting frame, and the supporting frame is fixedly connected with the spraying assembly. The supporting frame is fixedly connected to the top of the base, the sealing heads are fixedly connected to the interior of the supporting frame, the cooling channel is fixedly connected between the opposite sides of the sealing heads, and the cooling pipe is fixedly connected to the interior of the cooling channel. The structure of the pipe is stabilized from the inside through preliminary cooling, stress concentration possibly generated by shock cooling is reduced, and therefore the quality of the pipe is improved, spraying cooling of the pipe is achieved through the spraying assembly, the effect of rapidly reducing the surface temperature of the pipe is achieved, and the pipe rapidly reaches the state close to the normal temperature.

The invention discloses a mass concrete composite anti-crack structure and a crack control construction method based on the mass concrete composite anti-crack structure. The composite anti-crack structure comprises a core common concrete layer, an outer side anti-crack concrete layer, a reinforcing mesh arranged between the core common concrete layer and the outer side anti-crack concrete layer, and a top anti-crack concrete layer. The method comprises the steps that firstly, the thickness of side face anti-crack concrete and the thickness of top face anti-crack concrete needing to be poured are calculated according to cracking risk assessment, the side face anti-crack concrete is poured firstly, then core common concrete is poured, and it is ensured that the pouring height of the side face concrete is always 20-30 cm higher than the core common concrete; and then the top surface is completely constructed by adopting anti-crack concrete. The reinforcing mesh subjected to special treatment is adopted, so that the overall stress of the composite structure is uniform, the overall anti-cracking performance and durability of the composite structure are improved through the outer side anti-cracking concrete, the construction technology is simple, meanwhile, a large amount of construction cost and operation and maintenance cost can be saved, and the composite structure is suitable for application and popularization.

The invention discloses a heat exchanger with a protection function for biodiesel preparation, and relates to the technical field of heat exchangers, the heat exchanger comprises heat exchange equipment and further comprises a protection device, a control device is fixedly installed on the front side of the heat exchange equipment, a liquid inlet pipe is fixedly installed on the left side of the heat exchange equipment, and a placing frame is fixedly installed on the left side of the heat exchange equipment; wherein the protection device comprises a connecting pipe, an adjusting hole, an adjusting frame, an L-shaped rod, a protection groove, a rotating rod, a protection disc and a limiting groove, the L-shaped rod moves upwards to be separated from the adjusting hole and release limiting of the connecting pipe, and after limiting of the connecting pipe is released, the connecting pipe is manually pushed to move in the direction close to the oil storage tank for butt joint; and through the protection disc, loosening or displacement of the connecting pipe caused by the fact that an operator accidentally touches the L-shaped rod can be effectively prevented, and therefore the risk of leakage or accidents is reduced.

The invention relates to the technical field of data mining, in particular to a method and system for intelligently generating a sheet metal part process model. The method comprises the following steps: acquiring structural data of a sheet metal part processing workshop, and carrying out topological structure analysis to generate a processing technology model; acquiring design data of sheet metal parts, establishing a three-dimensional model, and performing machining simulation by using a process model to obtain simulation data; integrating historical processing finished product feature data, extracting surface features, and obtaining actual finished product data; finished product parameterization description is carried out on the machining simulation data, surface defects of a finished product are evaluated, and defect data are obtained; the simulation machining stress distribution uniformity is evaluated, and surface quality influence factors are calculated; and optimizing the processing technology model according to the quality influence factor, and uploading to a management platform to execute a simulation generation task. The accuracy of the sheet metal part process model can be improved.

The invention discloses a multi-degree-of-freedom morphing wing based on a zero poisson ratio superstructure, and belongs to the technical field of morphing wings. The wing comprises a front edge section, a wing body and a rear edge section which are sequentially connected, the front edge section comprises an inner side front edge plate, a middle front edge plate and an outer side front edge plate, the wing body comprises a plurality of zero-Poisson-ratio honeycomb structures, each zero-Poisson-ratio honeycomb structure is formed by arraying a plurality of zero-Poisson-ratio unit cell cubic structures, and the adjacent zero-Poisson-ratio unit cell cubic structures share a connecting rod; the rear edge section comprises an inner side rear edge plate, a middle rear edge plate and an outer side rear edge plate; the inner-side front edge plate and the inner-side rear edge plate, the middle front edge plate and the middle rear edge plate, and the outer-side front edge plate and the outer-side rear edge plate are respectively connected through zero-Poisson-ratio honeycomb structures which are arranged along the chord length direction of the wing; the two sides of the middle front edge plate are connected with the inner side front edge plate and the outer side front edge plate through zero-Poisson-ratio honeycomb structures arranged in the extension direction of the wing correspondingly, and the two sides of the middle rear edge plate are connected with the inner side rear edge plate and the outer side rear edge plate through zero-Poisson-ratio honeycomb structures arranged in the extension direction of the wing correspondingly. The wing has four deformation functions of variable elongation, chord length, dihedral angle and camber, so that the aircraft can adapt to different flight environments and tasks.

The utility model provides an endoscope and a head end part thereof. The head end part comprises a head end seat shell and a forceps lifting seat, a containing cavity is formed in the head end seat shell, the containing cavity is communicated with an instrument channel of the endoscope and forms an extending window for extending out of a medical instrument, and an abutting part is arranged on the edge of the extending window; a first guide face extending from the far end to the end of the rotating shaft is arranged on the forceps lifting seat, the first guide face is used for supporting the medical instrument and guiding the medical instrument to a preset path, the first guide face is provided with an abutting position corresponding to the abutting portion, and when the forceps lifting seat is lifted to a preset angle, the abutting portion is located on the first guide face. The abutting position is matched with the abutting part to clamp and fix the medical instrument supported by the first guide surface; a positioning groove is further formed in the far end of the forceps lifting seat, at least part of the positioning groove is formed in the first guide face, the positioning groove is used for positioning the medical instrument located on a preset path, and the abutting position is located outside the positioning groove. Based on the scheme, the convenience of instrument replacement can be improved.

According to the modified fiber mining filling material and the preparation method thereof provided by the invention, through a dual modification technology of plasma treatment and a silane coupling agent, the uniform dispersity of fibers in a cementing agent is enhanced, and the properties such as rapid hardening, early strength and compressive strength retention rate of the filling material are remarkably improved. The filling material comprises cement clinker, solid waste, a retarder, an early strength agent, modified fibers, an accelerator, gypsum, a water reducing agent, a suspending agent and other raw materials, the modified fibers are treated through specific steps, surface functional groups are increased, and the compatibility and binding power of the modified fibers and a cementing agent are improved. The filling material disclosed by the invention has the advantages of good transportability, simplicity and convenience in construction, low cost and environmental protection characteristic, conforms to the development trend of green mining industry, is particularly suitable for being applied to mine filling and supporting, and has wide application prospects and social and economic values.

The invention discloses a method for manufacturing a functionally graded composite material through wire powder composite arc additive manufacturing, which comprises the following steps: firstly, carrying out surface treatment on a base material, enabling the surface of titanium alloy to expose fresh white bright metal luster by adopting a machining mode, and removing surface oil stains by using alcohol and acetone; according to the requirement of materials for the gas atmosphere in the additive manufacturing process, the flexible inert gas cabin is filled with appropriate gas, and the gas atmosphere is kept all the time in the additive manufacturing process. On the basis of the electric arc additive manufacturing technology, electric arc additive manufacturing of the functional gradient metal-based composite material is achieved through a wire powder composite device, and the key technology is that according to different position requirements of parts, the metal-based composite materials with different ceramic particle contents are manufactured in an additive mode; a gradient transition area is manufactured between two areas with large particle content difference, and large stress generated at an interface due to component mutation is reduced.

The invention relates to the technical field of nodular cast iron, in particular to a silicon-molybdenum-chromium-nickel-niobium nodular cast iron material and a preparation method thereof. The material comprises the following chemical components in percentage by mass: 3.0%-3.5% of carbon, 4.3%-4.7% of silicon, 0.1%-0.3% of manganese, less than or equal to 0.05% of phosphorus, less than or equal to 0.02% of sulfur, 0.7%-1.0% of molybdenum, 0.6%-0.8% of chromium, 0.4%-0.7% of nickel, 0.3%-0.6% of niobium, 0.03%-0.06% of magnesium, 0.05%-0.1% of rare earth, 0.006%-0.012% of antimony and the balance of iron. The preparation method comprises the steps of smelting, first-time spheroidizing and inoculation, second-time spheroidizing, second-time inoculation and heat treatment in sequence. According to the obtained nodular cast iron material, the form of graphite and the number of graphite nodules are improved, carbon elements are separated out as many as possible in the form of high-carbon phase-spheroidal graphite, generation of pearlite is reduced, and the mechanical strength and high-temperature resistance of nodular cast iron are improved.

The invention relates to an anti-explosion high-temperature-resistant explosion test pipeline design method based on finite element simulation, and belongs to the field of pipeline design and application. According to the method, mechanical and heat transfer behaviors of the pipeline under the combined action of high temperature and explosive shock waves are analyzed by simulating extreme working conditions such as explosion, fire blast and detonation, and the safety performance of the pipeline is improved. The method comprises the following specific steps: firstly, setting explosion working condition parameters based on test requirements and related standards; secondly, establishing a three-dimensional finite element model, and performing fluid dynamic simulation analysis; then, through thermodynamics and explosion impact data analysis, temperature, pressure and stress distribution is obtained, and design parameters such as the geometric structure, the material and the wall thickness of the pipeline are optimized; and finally, verifying the safety and the stability through experiments. The method improves the design efficiency and reliability, and is suitable for high-risk experiment environments such as petrochemical engineering and mines.

The invention belongs to the technical field of CPVC pipe preparation, and provides a high-strength toughened CPVC pipe and a preparation method thereof. Firstly, butadiene and divinyl benzene are copolymerized to form a high-crosslinking structure, rigid support is provided, butyl methacrylate and acrylonitrile are copolymerized, flexibility and polarity are adjusted, interface bonding force is enhanced, and acrylic acid, epoxy acrylate and ethyl methacrylate are copolymerized to optimize compatibility with a matrix; secondly, through copolymerization of monomers such as 2-sulfonic acid ethyl methacrylate, polyethylene glycol methacrylate and dimethylacryloyloxyphosphonic acid, the polarity and flexibility of the compatilizer are adjusted, and the interface bonding strength of the compatilizer to a CPVC matrix and a modified elastomer is improved, so that the mechanical property of the composite material is remarkably improved; finally, nano SiO2 is subjected to surface modification through a silane coupling agent, so that the dispersity of the inorganic filler and the binding force with a matrix are improved, and the rigidity and the thermal stability of the composite material are enhanced.

The invention relates to a degradable epoxy resin curing process regulation and control method based on dielectric parameter real-time monitoring, and the method specifically comprises the following steps: S1, weighing raw materials according to a ratio, and mixing the raw materials to obtain an epoxy resin prepreg; s2, pouring epoxy resin prepreg in the electric field module, and connecting a power supply to monitor dielectric parameters; s3, placing the epoxy resin prepreg with the sensor in a set curing process environment, carrying out a curing procedure, and calculating to obtain a change curve of dielectric parameter values of different materials along with time; s4, regulating and optimizing a curing process to obtain an optimized curing process; and obtaining a change curve of the conductivity value along with time. A more reasonable heating rate and a temperature platform are set, so that the curing process is more uniform, the stress concentration in the material is reduced, the formation probability of microdefects is reduced, the cross-linking reaction is more sufficient, the internal structure of the material is more stable, the density of a formed cross-linked network is higher, and the overall mechanical property and dielectric property are further improved.

The invention belongs to the technical field of keel bending, and particularly relates to an automatic bending device for a light steel joist, which comprises a conveyor, a bending assembly is arranged above the conveyor, and the device is provided with the bending assembly, so that the light steel joist can be attached to the surface of the bending assembly to be subjected to pre-deformation bending treatment; the light steel joist is subjected to small-angle deformation before formal bending treatment, so that the resilience after edge folding can be reduced, the residual stress in the light steel joist can be released, the possibility of quality problems such as deformation and cracking caused by stress concentration is reduced, the structural strength and durability of the light steel joist are enhanced, and the service life of the light steel joist is prolonged. The stability and reliability of the whole structure are guaranteed, the internal stress distribution is more uniform and reasonable, so that the machining precision and the product quality are improved, the bending consistency of the light steel keel is guaranteed, manual intervention is not needed, the automation degree of the bending process is greatly improved, the labor intensity is relieved, and the production efficiency is improved.

The invention provides a method for stably controlling the surface quality of a high-carbon steel continuous casting billet, which comprises the following steps: high-carbon steel refined molten steel is poured, and the superheat degree of a tundish of the high-carbon steel refined molten steel is 10-25 DEG C; casting powder is added after steel drawing; the pulling speed of the casting is 0.85 to 1.30 m / min; and the high-carbon steel continuous casting billet obtained through pouring is cooled. According to the method for stabilizing the surface quality of the high-carbon steel continuous casting billet, through optimization and adjustment of a production process and cooperation with special casting powder, process parameters such as the pulling speed, the superheat degree and the one-cooling-water slow cooling mode special for the high-carbon steel are formulated, the quality stability of the high-carbon steel is effectively improved, and the percent of pass of the casting billet is increased.

The invention relates to the technical field of lamination processes, in particular to a double-layer glue and three-layer film method for manufacturing a diamond sticker, which comprises the following steps of: setting the total thickness of a film layer based on a top PET film, a glue layer and a substrate PET film, distributing the total thickness to the boundary of the film surface and the glue layer, adjusting the thickness of the PET film, loading the interface thickness control variable of the glue layer, and adjusting the thickness of the glue layer. And generating initial parameters of the film layer structure. According to the method, the lamination loads of different areas of the film layer are decomposed through a finite element analysis algorithm, the loads of multiple areas are uniformly distributed on the surface of the film, the problem of local pressure bearing unbalance easily occurring in a traditional lamination process is avoided, and the thickness of the film layer and the thickness of the adhesive layer are reasonably distributed in the design stage; different functional layers can effectively bear stress in the pressing process, the stress concentration phenomenon between layers is reduced, the pressure is adjusted point by point through multivariate analysis, the overall stress distribution is optimized, and the uniformity and stability of the film layer under the pressure are guaranteed.

The invention provides a detachable high-adaptation conductive adhesive test seat and adaptation equipment thereof, and relates to the technical field of chip tests.The test seat comprises a base, a bottom plate and a connecting frame, two connecting blocks are arranged in the base, the opposite faces of the two connecting blocks are fixedly connected with fixing blocks, the base is internally provided with a test seat, and the test seat is fixedly connected with the bottom plate. The control system determines corresponding clamping parameters including the stroke of the air cylinder, the clamping force and the like according to the type and the specification of the chip, the control system sends out an instruction to drive the air cylinder to start acting, a piston rod of the air cylinder stretches out and drives the clamping block to move towards the chip, and the clamping block accurately clamps the chip according to the preset position and force. According to the automatic chip testing device, the chips are ensured to be stable in the testing process, so that automatic adaptive fixation of different chips is realized, the identification and adjustment processes can be quickly completed through automatic identification and adaptive functions after the chips are put into the device, the manual intervention time is greatly shortened, and the overall automation degree and the testing efficiency are improved.

The invention provides a manufacturing method of a material storage plastic container with reinforcing ribs, and belongs to the technical field of material storage containers, initial data is obtained through a limit-general experiment, a reinforcing rib parameter equation set is constructed, and finite element analysis software is used for iterative optimization. Candidate parameters are screened by adopting an expansion-increasing Latin hypercube experimental design method, small-batch prototype samples are manufactured, and comprehensive performance detection such as static load, fatigue, environmental adaptability, impact resistance, chemical corrosion, temperature adaptability, sealing performance and compressive deformation resistance is carried out. And parameters with the optimal comprehensive performance are selected based on the detection result, and the injection molding technology is accurately set and comprises temperature control, mold design and surface treatment. The production line environment and quality are strictly controlled, large-scale production of the material storage plastic container is finally achieved, stable and reliable product performance is ensured, and the problems that an existing material storage plastic container is insufficient in bearing capacity and deformation resistance and short in service life are solved.

The invention provides a foldable display screen and foldable electronic equipment. The foldable display screen comprises a display light-emitting layer, a light-transmitting cover plate layer and a first supporting layer, the display light-emitting layer comprises at least one non-bending display area and at least one bending display area, and the non-bending display area and the bending display area are arranged adjacently; the light-transmitting cover plate layer is arranged on the display side of the display light-emitting layer and covers the non-bending display area and the bending display area. The first supporting layer is arranged on the side, away from the light-transmitting cover plate layer, of the display light-emitting layer and covers the non-bending display area and the bending display area, the first supporting layer comprises at least one non-bending supporting part and at least one bending supporting part, the non-bending supporting part is supported on the side, away from the light-transmitting cover plate layer, of the non-bending display area, and the bending supporting part is supported on the side, away from the light-transmitting cover plate layer, of the bending display area. The bending supporting part is supported on the side, away from the light-transmitting cover plate layer, of the bending display area, and the thickness of the bending supporting part is smaller than that of the non-bending supporting part. According to the foldable display screen and the foldable electronic equipment provided by the invention, the protection effect can be enhanced, and creases can be reduced.

The invention discloses a steel structural part drilling device and a using method thereof, and relates to the technical field of steel structure machining.The steel structural part drilling device comprises a bottom plate, a sliding table is fixedly connected to the middle of the upper surface of the bottom plate, notches are formed in the left side and the right side in the sliding table, and a plurality of movable guide rollers are rotationally connected into the two notches; a mounting groove is formed in the inner bottom surface of the sliding table, a jacking assembly is fixedly mounted in the mounting groove, a rotating assembly is arranged above the sliding table, a moving assembly is fixedly connected to the front side of the upper surface of the bottom plate, and a feeding assembly is fixedly mounted on the upper surface of the bottom plate and the rear side of the moving assembly; a bidirectional lead screw is rotationally connected between the two fixing seats, and moving blocks are in threaded connection with the left side and the right side of the outer surface of the bidirectional lead screw. The drilling device has the advantages that the drilling device is fixed at the drilling position, drilling accuracy can be ensured more directly, errors are reduced, and deformation of a pipe fitting in the drilling process is reduced by fixing the pipe fitting close to the drilling position.

According to the antibacterial and antioxidant composite film applied to food preservation and the production method of the antibacterial and antioxidant composite film, the chlorogenic acid, the catechin, the montmorillonite and the zeolite are introduced, and a drying process is optimized, so that the antibacterial performance, the antioxidant performance and the mechanical performance of the preservative film are remarkably improved, and meanwhile, the water vapor permeability and the oxygen permeability are reduced. The method comprises the specific steps of raw material preparation, polyphenol compound and mineral substance preparation, membrane liquid preparation and treatment, drying process optimization and finished product membrane uncovering. According to the preparation method disclosed by the invention, components such as chlorogenic acid, catechin, montmorillonite and zeolite are introduced, and a drying process is optimized, so that the food preservative film with synergistic antibacterial and antioxidant properties is prepared.

The invention belongs to the technical field of continuous casting roller bearing seat repairing, and particularly relates to a novel auxiliary device for repairing a continuous casting roller bearing seat and a repairing method. The device comprises a rotating support which is placed on a workbench and used for supporting and positioning the repairing device; the vibration module is vertically and rotationally mounted at the top end of the rotating support and used for vibrating the supporting plate and the clamping assembly mounted at the top end of the supporting plate so as to eliminate stress; the supporting plate is fixed above the vibration module; the clamping assembly is installed on the supporting plate, the clamping assembly comprises a handle and two limiting plates, and the distance between the two limiting plates is reduced by rotating the clamping assembly, so that the two limiting plates clamp the continuous casting roller bearing seat. According to the invention, the repairing quality and the working efficiency can be improved, and the safety and the convenience of operation are enhanced.

A splitting method of a solar cell comprises the steps that the solar cell is provided, the solar cell comprises an upper surface and a lower surface which are opposite to each other, and a scribing direction is set on the upper surface or the lower surface; first laser is adopted for scanning in the scribing direction, and the first laser enables the solar cell to be heated to generate pressure stress; meanwhile, cooling jet flow is sprayed in the scribing direction, the cooling jet flow enables the solar cell to be cooled to generate tensile stress, and along with movement of the first laser and the cooling jet flow, the center of the pressure stress and the center of the tensile stress do not coincide in the horizontal direction perpendicular to the scribing direction, so that the solar cell cracks in the scribing direction to form a fracture surface, and the fracture surface is formed. The section obliquely connects the upper surface and the lower surface. According to the splitting method of the solar cell, the fracture surface obliquely extends, and the method has the advantages of being smaller in roughness, free of raised grains and more thorough in edge isolation. The invention further provides a splitting and passivating method of the solar cell, the solar cell and splitting equipment.

The invention discloses a wear-resistant hard alloy and a preparation method and application thereof, and belongs to the technical field of hard alloys, and the wear-resistant hard alloy comprises the following components in parts by weight: 78.4-87.9 parts of tungsten carbide powder, 4-12 parts of high-entropy alloy powder, 2-8 parts of carbon nanotubes, 1-6 parts of titanium aluminum carbide and 0.1-0.6 part of tantalum carbide. The high-entropy alloy powder comprises, by weight, 1-3 parts of manganese powder, 2-5 parts of silicon powder, 5-12 parts of chromium powder, 10-15 parts of carbon powder, 10-15 parts of cobalt powder, 10-18 parts of molybdenum powder and 40-50 parts of nickel powder. The tungsten carbide powder comprises first tungsten carbide powder and second tungsten carbide powder in a weight ratio of (2-4): 1. The tungsten carbide powder serves as a matrix, under the combined action of the high-entropy alloy powder, the carbon nanotubes, the titanium aluminum carbide and the tantalum carbide, the wear resistance and the mechanical property of the hard alloy are remarkably improved, and the hard alloy can be well applied to preparation of cutting tools and drill bits and has wide application prospects.

The invention discloses a metal plastic deformation damage repair method based on high-frequency electric pulse, which comprises the following steps: S1, carrying out flaw detection on early damage of a damaged metal component, and determining a plastic deformation damage position in the metal component; s2, the damaged metal component is fixed to a pulse current processing device, and the damaged metal component and the exciting electrode are fastened through a clamp; s3, compressing the exciting electrode and the damaged metal component by using a high-temperature-resistant mica plate; and S4, pulse current signals are applied to the two ends of the damaged part, pulse current processing parameters are determined according to the size of the damaged metal component, and the damaged part is repaired through the determined pulse current parameters. According to the method, the problems of plasticity and toughness reduction, stress concentration, mechanical property reduction and the like caused by generation and accumulation of tiny plastic deformation of the material are effectively solved through pulse current repair, and meanwhile, the mechanical properties such as tensile strength of the material can be improved. And in-situ operation can be directly carried out by utilizing the electric pulse device, so that the material damage repair efficiency is improved.

The invention discloses a wide coal pillar lateral stress peak position blasting roof-cutting pressure relief method which comprises the following steps: step 1, according to a working face drilling histogram, calculating and determining a low-position key rock layer position by adopting a formula; 2, calculating the width of a working face coal pillar goaf side plastic zone by adopting a formula; 3, blasting drilling parameters are determined according to the position of the low-position key rock layer and the width of a plastic zone on the coal pillar goaf side; and 4, after blasting drilling parameters are determined, blasting drilling is conducted, in the working face advanced mining influence range, blasting top cutting is conducted on a working face air side roadway low-position key rock stratum cantilever structure, and continuous forward implementation is conducted along with working face stoping till working face stoping is completed. According to the method, the length of the lateral cantilever of the low-position key rock stratum of the goaf is reduced, the influence of the cantilever structure on stress concentration of the coal pillar is weakened, the internal stress of the coal pillar is reduced, and the stability of the goaf side roadway of the working face in the working face stoping period is ensured.

The invention discloses a method and system for determining the pressure relief drill hole spacing in a three-dimensional stress field, and relates to the field of drill hole spacing layer.The method comprises the steps that the roadway bearing pressure peak value range is obtained; acquiring corresponding crustal stress magnitude, crustal stress azimuth angle and inclination angle; the cohesion C, the internal friction angle phi, the Poisson's ratio v and the pressure relief drill hole radius of the roadway surrounding rock are determined; the stress is converted into a stress load under a drilling coordinate system through a coordinate conversion method; on the basis of a Kirsch solving method and by means of the determined drilling radius and the obtained stress load under the drilling coordinate system, the normal stress sigma r, sigma t and sigma v and the shear stress taurt, taurv and tautv of any point within the preset range of the hole under the drilling coordinate system are obtained; based on the M-C strength criterion of the three-dimensional state, the radius r of the pressure relief drilling anti-reflection ring is obtained through solving by means of rock mechanical parameters; and according to the r, the arrangement mode of the pressure relief drill holes is determined. Aiming at unreasonable pressure relief drill hole arrangement and unclear pressure relief parameters in the prior art, the method improves the normativity of roadway surrounding rock drill hole pressure relief.

The utility model relates to the technical field of linear push rods, in particular to a large-torque linear push rod. Comprising a rear end assembly; the sleeve assembly is arranged on one side of the rear end assembly; the motor assembly is arranged in the rear end assembly; the lead screw assembly is connected with the motor assembly, and the lead screw assembly is arranged in the sleeve assembly; the telescopic pipe assembly is arranged between the sleeve assembly and the lead screw assembly, and the motor assembly is fixedly connected with the lead screw assembly through a coupler; the coupler comprises a motor frame arranged at the output end of the motor assembly; the fixing base is arranged close to the motor frame, and the fixing base is arranged on the periphery of an inner lead screw of the lead screw assembly; and the fixed seat is in spline connection with the motor frame. The utility model has the advantages of larger thrust, good stability, simple structure, convenience in use and the like.

The invention relates to the technical field of epoxy resin, in particular to an epoxy resin composition for high-strength carbon fiber winding and a preparation method thereof.The preparation method of the epoxy resin composition comprises the steps that S1, modified epoxy resin, a compatilizer, a retarder, a defoaming agent and nano filler are added into a reaction kettle and mixed and stirred, and a mixture A is obtained; s2, a composite curing agent is added into the mixture A, stirring and mixing are conducted, and the epoxy resin composition is obtained and has the advantages of being appropriate in viscosity, good in heat resistance, excellent in impact resistance, large in bending strength, small in volume shrinkage rate in the curing process, moderate in gelation time and capable of being wound with carbon fibers conveniently to prepare the composite material.