668 results about "Shear strength" patented technology

The invention relates to the field of tunnel engineering geology and support design, and discloses a weak surrounding rock tunnel deformation risk discrimination method based on shear expansion-shear constitutive, which comprises the following steps: constructing a nonlinear coupling model between a shear expansion angle and shear stress, normal stress and joint parameters, and obtaining the shear expansion angle; establishing a volumetric strain rate discrimination formula; inverting an initial crustal stress tensor field; reconstructing an irregular tunnel boundary; constructing a risk level discrimination model, and outputting a risk level; supporting schemes such as supporting rigidity, anchor rod parameters and spraying layer thickness are matched according to the risk grades; establishing a model to predict a risk trend; a support adjustment suggestion is generated; collecting monitoring data to dynamically correct model parameters; and all the modules are integrated in a deployment system. According to the method, the coupling relation between the shear expansion angle and the shear strength is introduced, the coupling type constitutive discrimination model is established, the risk grading system and the support correction strategy associated with the support response are constructed, and active early warning of the high-risk section and dynamic adjustment of the support rigidity are achieved.

The invention relates to the technical field of defect detection, and discloses a Babbitt metal coating surfacing thin-wall layer defect detection method and device. The method comprises the following steps: carrying out multi-source detection data acquisition, multi-domain transformation and filtering enhancement on a babbitt metal coating, and obtaining preprocessed multi-source initial coating detection data to carry out interface-tissue-defect mapping, so as to obtain unified representation of an internal tissue structure of the coating; performing progressive fusion of a coating depth structure and extraction of coating defect morphology and structural features on the unified feature representation to obtain preliminary defect semantic features, and performing feature weighting calculation of defect morphology on the preliminary defect semantic features to obtain initial defect semantic features; and carrying out bearing strength and shear strength calculation and fatigue life prediction on the initial defect semantic features to obtain a final detection result. According to the method, the defects of the thin-wall layer coated and surfaced by the babbitt metal can be efficiently and accurately detected.

The invention belongs to the technical field of gate shaft construction, and particularly relates to a one-time forming pouring system and a one-time forming pouring method. The gate groove formwork and the vertical shaft sliding formwork assembly in the one-time forming pouring system can move in the depth direction of the gate shaft and jointly define a pouring ring, and when the strength of hydraulic concrete structures corresponding to the vertical shaft sliding formwork assembly and the gate groove formwork reaches the demolding strength, the gate groove formwork and the vertical shaft sliding formwork assembly are separated. The positions of the vertical shaft sliding formwork assembly and the gate groove formwork can be adjusted through the lifting device and the hoisting device, so that the pouring space rises in the depth direction of the gate shaft, continuous pouring of the hydraulic concrete structure is met, pouring of the hydraulic concrete structure does not need to be conducted step by step, joints are avoided, and the construction efficiency is improved. The integrity and shear strength of the hydraulic concrete structure are improved, so that the construction quality of the hydraulic concrete structure in the gate shaft is ensured, and meanwhile, the construction difficulty is reduced.

The invention discloses an ultrahigh-strength prestressed concrete pipe pile and a preparation method, and relates to the technical field of building materials. The ultrahigh-strength prestressed concrete pipe pile comprises a core layer which is composed of 1.0%-2.0% by volume of chopped basalt fiber reinforced concrete, the fiber length is 8-12 mm, the diameter is 15-20 microns, and the compressive strength is larger than or equal to 130 MPa; the transition layer is composed of hybrid fiber reinforced concrete with the volume fraction of 3.0%-4.0%, steel fibers account for 60%-75%, polyethylene fibers account for 25%-40%, the length-diameter ratio of the steel fibers is 50-80, and the tensile strength is larger than or equal to 1200 MPa. Through gradient fiber reinforced structure design and preparation process innovation, the mechanical property, the production efficiency and the environmental friendliness of the prestressed concrete pipe pile are synergistically improved. Firstly, in the aspect of mechanical properties, the compressive strength is made to break through 130 MPa through the synergistic effect of the core layer basalt fiber and the high-activity superfine slag powder and is improved by 30% or above compared with a traditional C100 pipe pile, and meanwhile the shear strength is improved to 18 MPa or above through a transition layer steel-polyethylene hybrid fiber system.

The invention belongs to the technical field of titanium-steel composite plates, and particularly relates to a production process for preventing grain growth of a titanium-steel composite plate, which comprises the following steps: roughening the lower side surface of a titanium plate and the upper side surface of a steel plate by adopting a sand blasting process; an additive is sprayed to the upper side face of the steel plate and the lower side face of the titanium plate, the additive comprises boron powder and a binding agent, graphite foil is laid on the upper side face of the steel plate sprayed with the additive, the titanium plate sprayed with the additive is stacked on the steel plate, and the graphite foil is clamped by the upper side face of the steel plate and the lower side face of the titanium plate to prepare a composite plate blank; sealing the edge part of the composite plate blank by using a sealing material; the production process comprises the following steps: heating a composite plate blank through a heating furnace, rolling and cooling the heated composite plate blank, straightening the composite plate blank through a straightening machine, and trimming the straightened composite plate blank to obtain the titanium-steel composite plate. And the bonding strength and the shearing strength of the titanium steel composite plate are improved.

The invention discloses a production method of a T2+Q355B copper steel rolled composite plate. The technological process comprises the steps of assembling, heating, rolling, stack cooling, finishing, flaw detection and warehousing. A T2 + Q355B copper steel rolled composite plate with excellent bonding strength, mechanical property and conductivity is obtained by adopting a vacuum rolling composite technology, a symmetric assembly technology and a low-speed deformation technology and utilizing wide and thick plate production line equipment and technical advantages, the thickness of a base material ranges from 5 mm to 40 mm, the thickness of a composite layer ranges from 1 mm to 20 mm, the width is smaller than or equal to 3600 mm, the yield strength is larger than or equal to 250 Mpa, the tensile strength ranges from 350 Mpa to 600 Mpa, the shear strength is larger than or equal to 120 Mpa, and the composite layer T2 copper conductivity IACS is larger than or equal to 85%. The intergranular corrosion crack rate is 0. The product can be widely applied to the fields of high-voltage electric appliances, ship manufacturing, new energy equipment and the like, and has the potential of replacing traditional products.

Building techniques and structures to fabricate components of expanded polystyrene (EPS) for assembly into a building include structures and ways to make keys to provide shear strength between components, structures and ways to minimize infiltration paths between walls and floors and walls and roof while reducing labor, material wastage and logistics complications. By way of example, components are strategically cut from a block of EPS using a hot wire moving through the block to cut components to a desired and novel configuration.

Provided are a solder alloy, a solder ball, a preformed solder, a solder joint, and a circuit, which are excellent in wettability and shear strength, suitable in failure mode, capable of suppressing the growth of an intermetallic compound at a bonding interface even after multiple reflow soldering, excellent in drop impact resistance, and suitable in the shape of a bump. The solder alloy has an alloy composition comprising, in mass%, 0.10 to 3.00% of Ag, 0.80 to 6.00% of Cu, 0.08 to 0.60% of Ni, 0.0010 to 0.0150% of Ge, and the balance of Sn. It is preferable that the alloy composition further contains 0.1% or less of at least one of Bi, Sb, In, Zn, Ga, Mn, Cr, Co, Si, Ti, and rare earths in total.

The invention discloses a gabion gabion net cage system for reinforcing a high-fill embankment of an expressway, belongs to the technical field of gabion gabion net cages, and solves the problems that in the prior art, external loads are resisted only through self-strength, and the gabion gabion net cage system and a filling body are difficult to form a synergistic deformation whole, so that the structure is cracked and fails. The system comprises an excavation roadbed, at least one group of filling slope foundations, gabion gabion gabion net cages and backfill discrete materials, according to the gabion gabion gabion grid net cage, through the synergistic effect of tensile resistance of the steel wire mesh and shear resistance of the block stones, the gabion gabion gabion grid net cage and the filling discrete material form a flexible-rigid composite structure, so that the high tensile property of the steel wire mesh can effectively restrain horizontal displacement and deep slippage of the filling material, and deformation of a side slope along a potential slippage face is restrained; and the gradation matching performance of the block stone filling structure and the backfill discrete materials enhances the occlusion effect between the materials, and the shear strength and the overall rigidity of the slope are remarkably improved.

The invention discloses an angle steel connecting piece shear strength prediction method and system based on a physical information neural network, electronic equipment and a storage medium thereof. The method comprises the following steps: establishing a database containing a plurality of groups of test data based on a numerical simulation result of an angle steel connecting piece finite element model verified by a push-out test; embedding an angle steel connecting piece shear bearing capacity physical constraint condition based on an elastic foundation beam theory into a loss function of the data-driven neural network model DNN; training the neural network embedded with the physical constraint condition by using a database, and adjusting and selecting a physical item weight factor and a model learning rate so as to construct a shear bearing capacity prediction model of a physical information neural network (PINN); predicting the shear strength of the angle steel connecting piece by using the trained physical information neural network (PINN) shear capacity prediction model; according to the prediction method and system, the electronic equipment and the storage medium thereof provided by the invention, the accuracy and reliability of the shear resistance prediction of the angle steel connecting piece can be improved.

The invention discloses a V-shaped slope stability calculation method and system, and relates to the technical field of open-pit mining. On the basis of a three-dimensional numerical simulation technology, the damage mode of the sliding body is judged, a spatial form equation of a potential sliding body is determined firstly, then the sliding body is divided into micro-strip columns in a regional mode, the stress state of the micro-strip columns is solved through a constitutive relation and a static balance condition, and the force of each row of micro-strip columns is superposed in the direction of a main sliding surface; and obtaining two-dimensional equivalent shear strength parameters with a three-dimensional effect on each row of main sliding surface micro-strip columns by using an equivalent thought, and then deducing a three-dimensional V-shaped slope stability coefficient by using a rigid body limit equilibrium method. According to the method, the problems of high calculation cost, difficulty in parameter determination and complex calculation process in a traditional slope three-dimensional stability calculation method are avoided, the problem of three-dimensional stability of the slope in the special form is solved, a more reliable theoretical technology is provided for design, mining, prevention and treatment of the slope, and the method is worthy of popularization and application. The method has important practical significance for guaranteeing safe and efficient production of mining.

The invention discloses a method for evaluating damage evolution of an underground structure under the action of a sudden explosion load, and relates to the technical field of civil engineering and engineering disaster prevention, and the method is characterized by comprising the following steps: S1, simulating the underground structure based on an explosion load, a geometric boundary and material parameters, and constructing a unified constitutive model; and S2, introducing a pressure-related strength criterion of a Dwark-Prasugrel criterion into the unified constitutive model so as to describe the influence of confining pressure on the shear strength. The technical problem to be solved by the invention is to provide the method for evaluating the damage evolution of the underground structure under the action of the burst explosion load, so that the key pain points such as pressure correlation, high strain rate effect, material random discreteness, damage softening energy consistency and the like are difficult to consider at the same time in the existing analysis method. A set of damage evolution evaluation method and implementation system which can be implemented from the material level to the structure level is established, and quantitative prediction and engineering grading judgment of the whole process of crack initiation, expansion to instability failure of the underground structure are supported.

The invention relates to the technical field of metal material fracture resistance testing, in particular to a prediction method for interface fracture toughness of a polar region ship composite steel plate, which comprises the following steps: S1, preparing a composite steel plate; s2, carrying out a three-point bending fracture test; s3, performing an interfacial shear strength test; s4, data analysis and model construction: performing fitting analysis on the obtained fracture toughness data of the large-size sample and the obtained shear strength data of the small-size sample, determining undetermined parameters, and constructing a mathematical model between the interface fracture toughness and the interface shear strength of the composite steel plate; and S5, verifying the accuracy of the model. According to the method, the mathematical model is established by analyzing the correlation between the shear strength measured by the small-size interface shear sample and the fracture toughness measured by the large-size fracture sample, and the model has the advantages of simplicity in construction, rapidness in use and the like, so that rapid prediction and evaluation of the fracture toughness of the composite steel plate are realized, the test process is greatly simplified, and the test efficiency is improved. And the research and production efficiency is improved.

The invention discloses a hole slag back pressure backfilling and roadbed structure integrated construction technology, and belongs to the technical field of road construction. Comprising the following steps: grading and screening the tunnel hole slag into large / medium / fine three-level aggregate, and then crushing and recombining to form graded improved aggregate; constructing a multi-layer backfill structure of a base layer, a transition layer and a reinforcing layer; interface shear strength is achieved through the gravel-geogrid composite transition layer; adopting a vibratory roller to implement a static pressure and vibratory rolling combined process with adaptive levels; a coarse / fine-particle-size two-stage cement stabilized macadam layer is laid on the top to form a permeation drainage channel, and a transverse drainage blind pipe system is arranged to achieve three-dimensional drainage. According to the technology, the problems that in traditional hole slag backfilling, aggregate grading discreteness is large, shear failure is likely to be caused by sudden change of interlayer modulus, interlayer combination weakening is caused by uneven layered rolling energy transfer, and structure instability is caused by pore water pressure accumulation are solved, and hole slag resource utilization and roadbed structure performance collaborative improvement are achieved.

The invention discloses a low-temperature connecting method for glass and a C / C composite material, and relates to a connecting method for the glass and the C / C composite material. The problems that the performance of a base material is reduced and interface bonding is poor due to the fact that the connection temperature of an existing C / C composite material and glass is too high are solved. According to the method, firstly, a metal modified layer is prepared on the surface of the C / C composite material through magnetron sputtering, a carbide reaction layer is generated at the interface of the composite material, then connection of the C / C composite material and microcrystalline glass is achieved at the temperature of 580-660 DEG C through Bi2O3-B2O3-ZnO glass brazing filler metal, a microstructure mainly comprising a glass phase is formed in a welding seam, and the welding seam is formed. A continuous reaction layer is generated at the interface of the glass brazing filler metal and a glass base material, the glass brazing filler metal and the C / C composite material are connected through direct combination of oxides on the surface of a metal modified layer, and formed welding seams are compact and free of defects such as air holes and cracks. And the shear strength of the obtained joint can reach 13MPa.

The invention discloses a method for calculating the shear strength of a weak structural plane based on a Barton formula, and relates to the field of shear strength calculation, and the method comprises the following steps: introducing a reduction coefficient into a traditional Barton formula, and constructing an improved Barton formula; the shear strength of the weak structural plane is calculated through an improved Barton formula; the improved calculation model is regressed into an original Barton formula when no filler exists, theoretical continuity is guaranteed, compatibility with a traditional model is achieved, meanwhile, the defects of the traditional model are well overcome, and an important theoretical basis is provided for prediction of the shear strength of the weak structural plane. An improved Barton formula is utilized, the weakening effect of the soft filler on the rock mass structural surface can be reflected, the relation between the thickness of the soft filler and rock wall roughness attenuation can be accurately quantified, and compatibility with a traditional model is achieved; and the applicability, reliability and precision of prediction of the shear strength of the weak structural plane are effectively improved.

The invention relates to the technical field of slope reinforcement, and provides a micro pile combination reinforcement method for a highway expansive soil slope, which comprises the following steps: when the current stability safety coefficient, the current uplift bearing capacity, the current shear strength and the current flexural bearing capacity all meet the corresponding preset conditions, taking the current design size parameter as the final design size parameter; and according to the final design size parameters, the grouting amount of each hole in a first pile of the steel pipe pile assembly and the grouting amount of each hole in a second pile of the cast-in-place pile assembly are determined, and the steel pipe pile assembly is constructed on the slope bottom face of the expansive soil slope according to the grouting amount of each hole in the first pile. And then a cast-in-place pile assembly is constructed on the slope face of the expansive soil slope according to the grouting amount of each hole in the second pile. According to the method, the influence of the expansive soil property on design and construction of the micro piles is fully considered, interaction and combined arrangement of the micro cast-in-place piles and the micro grouting steel pipe piles are integrated, the safety and reliability of slope reinforcement are guaranteed, material waste caused by excessive conservative is avoided, and operability is high.

The invention relates to the technical field of welding and connection, in particular to a method for improving the mechanical property of an aluminum alloy resistance spot welding joint, which comprises the following steps: preparing active adjuvant paste, placing the adjuvant paste in an extrusion device, coating at the corresponding position of a welding spot through automatic equipment such as a mechanical arm, adjusting corresponding spot welding parameters, and performing resistance spot welding. And forming a spot welding joint. In the resistance spot welding process, the active auxiliary agent added to the interlayer interface of the plate can remove an oxidation film on the surface layer of the aluminum alloy, adjust interface resistance and stabilize current distribution, so that the nugget size and form of a spot welding joint are improved, and splashing is reduced; and meanwhile, the active auxiliary agent reacts in the high-temperature molten aluminum to play roles in purifying melt and refining grains, so that the mechanical property of the aluminum alloy resistance spot welding joint is improved. Under the same test condition, the nugget size of the aluminum alloy resistance spot-welded joint added with the active auxiliary agent is increased by 10%, the grain size is reduced by 10-15%, and the tensile-shear strength of the joint is increased by 15-20%.

The invention provides a construction method of a zipper horizontal pulling strength determination model and related equipment, and the method comprises the steps: constructing a first expression of the zipper horizontal pulling strength according to the friction force and the shear bearing force of the zipper horizontal pulling strength decomposition on the contact surface of a tooth head and a tooth groove, the shear bearing capacity is obtained according to the effective contact width of the tooth head, the effective occlusion depth of the tooth socket and the shear strength expression of the zipper material; based on the stress balance condition, a second expression of the horizontal pulling strength of the zipper is constructed according to the dip angle of the tooth head, the friction force and the normal force corresponding to the friction force; the first expression and the second expression are combined to construct a zipper horizontal pulling strength determination model, the zipper horizontal pulling strength determination model suitable for different materials and different tooth head structures is constructed, and the efficiency of horizontal pulling strength prediction and zipper optimization design is improved.

The invention relates to the field of buildings, and discloses a prefabricated pipe pile stand column steel supporting node and a construction method thereof.The prefabricated pipe pile stand column steel supporting node comprises a prefabricated pipe pile stand column, a pile head is arranged at the top of the prefabricated pipe pile stand column, a micro-expansion concrete filling core is arranged in the prefabricated pipe pile stand column, and the bottom end of the micro-expansion concrete filling core is fixedly connected with a round thin steel plate through anchor bars; the top ends of the anchor bars are fixedly connected with anchor plates, overflow holes are formed in the anchor plates, and the top faces of the anchor plates are exposed out of the pile head. Longitudinal steel reinforcement frameworks and transverse stirrups are arranged in the pile head to form a steel reinforcement mesh cage, a micro-expansion concrete filling core is poured by adopting a layered pouring and layered vibrating process, and end hook type steel fibers are doped, so that concrete shrinkage can be compensated, cracks are inhibited, and meanwhile, the bending strength and the shearing strength of the pile head are enhanced; and the load of the steel support can be uniformly transmitted to the prefabricated tubular pile stand column through the anchor plate, so that the node has reliable bearing capacity and crack resistance.

The invention relates to the technical field of metal stamping, in particular to a door lock assembly automatic production system based on a stamping process, comprising a feeding module for feeding plates; the positioning module is used for limiting the position of the mold; the guide module is used for adjusting the position of the male die according to the offset and the change trend; the conveying module is used for moving the plate between the stamping stations; the stamping module is used for stamping the plate and adjusting the initial stamping force, the pressure threshold value and the stroke; the detection module is used for detecting the number of discharged pieces, the thickness of the plate, the depth of the plate, the coordinates of the mold and the blanking duration; and the analysis module is used for judging whether the current production efficiency meets the production requirements and reasons or not, analyzing the shear strength of the plate and the offset change degree of the die and judging whether the plate can be adjusted back to be punched again or not. The punching parameters are adjusted according to the shearing strength of the plate and the deviation change condition of the punched hole, and the production efficiency and the production precision are improved.

The present application relates to a microbial grouting treatment soft foundation construction structure and its construction method. The scheme includes the following steps: improving the shear strength and bearing capacity of the soft foundation and reducing the compressibility and permeability of the foundation soil by setting up heap loading, microbial high-pressure rotary jet piles and microbial tree root steel pipe piles; draining the moisture in the foundation and eliminating or weakening the liquefaction characteristics of the foundation soil by heap loading in conjunction with drainage steel pipes, mesh water collection pipes and pumps; and improving the cooperative working ability of the microbial high-pressure rotary jet piles and the soil between the piles by setting up a microbial sand solidification layer, ensuring deformation coordination and preventing uneven settlement. The grouting material adopts a two-component microbial grouting material, which is safe, clean and environmentally friendly. The microbial induced calcium carbonate precipitation material has the advantages of fast speed and high efficiency. The induced precipitation of calcium carbonate can be completed in about a few hours, which greatly shortens the construction period and will not cause sewage to flow across the land and pollute the environment.

The invention relates to Ni3Al-based alloy powder for laser cladding of a copper alloy surface, a cladding layer and a preparation method of the Ni3Al-based alloy powder, belongs to the technical field of laser processing materials, and is used for solving at least one of the problems of poor abradability, low hardness, low interfacial shear strength and the like of an existing copper alloy cladding layer. The Ni3Al-based alloy powder comprises the following chemical components in percentage by mass: 6.6%-7.1% of Al, 3.0%-3.5% of C, 34.5%-37.5% of Cr, 0.041%-0.06% of B, less than or equal to 200ppm of O, less than or equal to 30ppm of N, less than or equal to 5ppm of H and the balance of Ni. By adopting the Cr7C3 reinforced Ni3Al-based alloy powder provided by the invention, a cladding layer which is compact in organization structure, high in bonding strength with a matrix and excellent in wear resistance can be directly prepared on the copper surface. Specifically, the average hardness of a cladding layer on the surface of the copper alloy is larger than or equal to 490 HV, the shear strength of an interface is larger than or equal to 350 MPa, and under the dry friction condition (point friction and opposite grinding materials are Si3N4), the room-temperature wear rate is smaller than or equal to 1.85 * 10 <-5 > mm < 3 > / (N.m), and the wear rate at the temperature of 300 DEG C is smaller than or equal to 2.00 * 10 <-5 > mm < 3 > / (N.m).

The invention discloses a slope structural surface roughness coefficient testing method. The method comprises the core steps of structural surface pretreatment, rebound detection, contour curve drawing, roughness measurement and the like. Measuring areas are divided and identified, an average rebound value is obtained by using a rebound apparatus, a surface profile is drawn in combination with a profile curvimeter, and a roughness coefficient JRCn is read by using a multi-range roughness ruler and an electronic subdivision technology; in addition, parameters such as rock wall strength and normal stress can be obtained through a point load instrument, a vibrating wire strain gauge and the like, shear strength is calculated in combination with a Barton-Bandis mode, data of multiple measuring areas are integrated, and dynamic correction results of environmental parameters are associated. According to the method, the test precision and efficiency are improved, data integration and full-period management are realized, and a reliable basis is provided for slope stability evaluation.

The invention relates to the technical field of geotechnical engineering anchoring, in particular to a method for testing the degradation characteristic of the bearing performance of a recyclable anchor rod under cyclic loading. The method comprises the following steps: preparing a unit body sample anchor-rock interface unit body sample, simulating weathered soft rock according to a specific ratio, pouring a self-compacting concrete anchoring body, and curing and forming; setting a combined parameter of a reference load ratio and a load cycle index, applying a triangular wave cyclic load to simulate a traffic condition, and executing a pull-out test to collect load-displacement data; constructing a two-parameter coupled shear strength degradation model based on test data, and proposing a shear stress-displacement curve model; an anchor rod load transfer control equation is established in combination with the Poisson effect, and shear stress distribution of the anchoring section is iteratively solved by adopting a discrete recursion method; the model is verified through a foundation pit engineering case, the ultimate bearing capacity degradation law of the anchor rod under long-term cyclic loading is predicted, and it is proved that the model can guide engineering safety design. According to the method, the coupling characterization of the cyclic load parameter and the interface degradation mechanism is realized.

The invention relates to a ring groove rivet sleeve and a high-strength ring groove rivet for aerospace, the rivet sleeve comprises a bulged section, a connecting section and a locking section which are sequentially distributed in the axial direction, and the material strength of the bulged section and the locking section is smaller than that of the connecting section. According to the rivet sleeve, the bulged section, the connecting section and the locking section are sequentially distributed in the axial direction, the bulged section penetrates through the hole of the connected piece during riveting, the connecting section is located in the hole in the connected piece, the locking section abuts against the side face of the connected piece, the bulged section is bulged and deformed in the riveting process, and the locking section is located in the hole in the connected piece. Meanwhile, the locking section is extruded to deform and is filled into a thread groove in the rod part of the nail rod to realize locking; due to the fact that after riveting is completed, the rivet mainly bears shearing force through the connecting section, the material strength of the connecting section is set to be larger than that of the bulging section and the locking section, smooth deformation of the bulging section and the locking section can be guaranteed, meanwhile, the structural strength of the connecting section is improved, the connecting section has high shearing strength, and the service life of the rivet is prolonged. And the shear resistance of the rivet can be effectively improved.

The invention discloses a pull rivet connecting piece and a lantern ring preparation method and application thereof, the pull rivet connecting piece comprises a pull rivet and a lantern ring, and a preformed directional deformation protrusion is arranged on the cylinder wall of the lantern ring and located in a preset bulging deformation area. In the rivet pulling process, the directional deformation protrusion preferentially generates radial plastic deformation when being axially compressed, so that a drum-shaped locking structure which is accurate in position and uniform in shape is formed, and the lantern ring is integrally formed through a local plastic deformation process and can be prepared through an internal reaming method or an external die assembly extrusion method. According to the lantern ring, it can be ensured that radial plastic deformation is evenly spread in the circumferential direction of the lantern ring through the directional deformation protrusions designed through the pre-forming structure, controllability and predictability of the deformation process are greatly improved, consistency, reliability and convenience of pull-rivet connection are kept through the design, the tensile strength and the shear strength of connection are remarkably improved, and the service life of the lantern ring is prolonged. The method is suitable for occasions with high reliability requirements.

The invention discloses a low-corrosion halogen-free soldering flux for aluminum-based part brazing and a preparation method of the low-corrosion halogen-free soldering flux, and belongs to the technical field of halogen-free welding materials.The low-corrosion halogen-free soldering flux comprises, by mass, 4-6 parts of oxalic acid, 1-2 parts of triethanolamine, 0.8-1.5 parts of Tween-80, 4-6 parts of polyvinylpyrrolidone, 0.3-1 part of compound nano cerium oxide, 0.5-1.5 parts of chitosan oligomer and the balance deionized water. And the welding spot oxidation resistance and the interface self-repairing capability are further improved. Through the synergistic effect of four mechanisms of complexing, oxidation prevention, wetting and film forming, the flux achieves efficient film removal, excellent wetting, no corrosion residue and stable film forming protection, is high in shear strength, low in welding spot porosity and clean in surface after welding, and is suitable for electronic packaging, heat exchanger manufacturing and high-reliability aluminum welding occasions.

The invention relates to a test tool and method for testing the shear strength of a material interface. The tool comprises a chuck, a fixing block, a base and a sliding block, a guide rail groove is formed in the base, one side of the guide rail groove is connected with the sliding block, and the other side of the guide rail groove is connected with the fixing block; the fixing block is provided with a fixing hole and a fixing block threaded hole, a pin penetrates through the fixing hole, the sample hole and the sliding block hole to fix the sample, and a bolt is fixed to the base through the fixing block threaded hole. The sliding block is provided with a sliding block sliding rail, a sliding block threaded hole and a sliding block hole, and the sliding block sliding rail is arranged in the guide rail groove of the base and fixed through a bolt; the chuck is located on the lower side of the base and serves as a device for connecting the base and the stretcher. According to the invention, the interface shear strength performance test can be carried out on the sample with any thickness, the bonding surface of the sample is always kept parallel to the axial force line in the initial sample mounting process and the tensile test process, and the bonding surface of the sample base material and the lap joint material in the initial test state is prevented from being abnormally damaged.

To provide a high strength stainless clad steel plate excellent in stress corrosion cracking resistance and low temperature toughness and a producing method thereof.SOLUTION: A stainless clad steel plate comprises a base material and a laminating material formed on the base material, wherein the laminating material has a specific composition, the base material has a specific composition, a yield strength of 620 MPa or more, a tensile strength of 700 MPa or more, and an absorbed energy of 47 J or more when a Charpy impact test is conducted at -40°C, and the clad steel sheet has a shear strength of SH: 0.87×((t+T)×YSC-T×YSB) / t or more, a yield strength of 620 MPa or more, and a tensile strength of 700 MPa or more.SELECTED DRAWING: None