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160results about How to "Reduce stress concentration" patented technology

Excavating method for jump-digging of double-side wall guide pit combined arch part of tunnel

ActiveCN102182466AReduce stress concentrationReduce surrounding rock disturbanceUnderground chambersTunnel liningSubsidenceStress concentration
The invention relates to a novel large-span tunnel excavating construction method, namely, an excavating method for jump-digging of a double-side wall guide pit combined arch part. After the construction of a double-side wall guide pit and side wall secondary lining is completed, a large-span tunnel arch soil body is excavated by blocks. During the excavation of the arch part of the tunnel, a middle guide pit of the arch part is excavated first, then two side guide pits of the arch part of the tunnel are excavated from the excavation surface of the middle guide pit to the two sides by departing from an opening, a primary supporting structure and the secondary lining of the arch part at the position are constructed, and then the excavation of a arch part structure of the tunnel with large span is completed gradually from inside to outside. The method considers the space effect of tunnel excavation and support, reduces stress concentration at the opening during the excavation of the arch part, and has remarkable effects in ensuring the stability of excavating surrounding rocks at the section of the tunnel with large span and controlling the settlement of a larger area caused by the tunnel excavation.
Owner:CHINA RAILWAY SHANGHAI DESIGN INST GRP

Water plugging device for petroleum pipeline maintenance

The invention discloses a water plugging device for petroleum pipeline maintenance. The water plugging device comprises a gasbag body and an exhaust pipe which is arranged at the end of the gasbag body. A plurality of grooves are formed in the outer circumferential wall of the middle of the gasbag body. Two elastic metal sheets are arranged in each groove in a spaced mode, and the bent part in each elastic metal sheet is fixedly provided with a reinforcing pad. When the gasbag body is inflated, the two elastic metal sheets in each groove deform to expand outwards in the radial direction of the gasbag body. Pressure in a gasbag is gradually increased, elastic deformation is made to occur to the elastic metal sheets, and the elastic metal sheets expand outwards in the radial direction of the gasbag body until the elastic metal sheets make contact with the inner wall of a pipeline. In the outward expansion process, elastic force generated by the deformation of the elastic metal sheets directly acts on scale on the inner wall of the pipeline and crushes the scale; the reinforcing pads fixed on the elastic metal sheets can weaken the impact strength between the scale and the elastic metal sheets, and the problem of stress concentration of the elastic metal sheets is solved.
Owner:JIANGSU PROVINCE JINFENG PETROLEUM MACHINERY MFG CO LTD

Hot and cold composite precision forging forming method of great-modulus high-thickness straight-tooth cylindrical gear

The invention provides a hot and cold composite precision forging forming method applied to a great-modulus high-thickness straight-tooth cylindrical gear, and belongs to the technical field of metal plastic processing. The hot and cold composite precision forging forming method adopts the following steps of: baiting, upsetting after heating, hot die forging, annealing middle treatment, cold forward extrusion, center hole processing, annealing middle treatment and cold finishing, wherein the deformation quantity is reasonably distributed in three forming work procedures, certain tooth shapes are formed by the hot die forging work procedure, then, the cold forward extrusion process is adopted for further forming complete tooth shapes, and better surface quality is formed through radial and axial material flowing. Through the center hole processing work procedures, the stress concentration phenomenon during the closed cold finishing can be effectively reduced, and the service life of a mold is improved. Through the cold finishing work procedure, the tooth surface precision can be further improved, simultaneously, the defect of imperfect gear sectional surface filling generated in the cold extrusion work procedure is eliminated, and finally, the tooth-shaped surface of a forge element can directly reach gear hobbing and gear milling precision.
Owner:BEIJING RES INST OF MECHANICAL&ELECTRICAL TECH +1

Floating clamp

The invention relates to a floating clamp. The floating clamp comprises a pressure box, wherein a plurality of jacking rods floating along an axial direction and used for jacking a specially-shaped part are assembled on at least one side surface except a reference surface, of the pressure box in a manner of guide sealing; one end of each jacking rod is located in the pressure box, and the other end of the jacking rod stretches out of the pressure box; working mediums used for pushing the jacking rods to axially float are arranged in the pressure box; and a space adjustment mechanism used for adjusting the size of a space where the working mediums are located is arranged on the pressure box. The space where the working mediums are located is reduced through the space adjustment mechanism, so that the working mediums push the jacking rods to axially float to jack the specially-shaped part; acting forces on the jacking rods are the same according to a hydraulic principle; the plurality of jacking rods form a plurality of equal-force fulcrums and the equal-force fulcrums act on different parts of the specially-shaped part, thus the acting forces acting on the specially-shaped part are effectively dispersed, the stress concentration of the specially-shaped part is reduced, and the deformation amount of the specially-shaped part is reduced.
Owner:HENAN PINGGAO ELECTRIC +2

Control method for corner cracks of boron-containing steel plate slabs

ActiveCN106825478AAlleviate initial cracksReduce stress concentrationSteel platesNarrow face
The invention belongs to the technical field of metallurgy, and particularly relates to a control method for corner cracks of boron-containing steel plate slabs. The production procedure of a boron-containing steel plate sequentially comprises molten iron pre-treatment, converter smelting, secondary refining and plate slab continuous casting. In the continuous casting process, the ratio of the water amount of a crystallizer to the product of the casting blank section size and the pulling speed is controlled to be 0.02-0.03; meanwhile, the ratio of the wide face water amount/wide face size of the crystallizer to the narrow face water amount/narrow face size is controlled to be 1-1.5; a full-width coverage spraying manner is adopted as a secondary cooling manner, and the ratio of the total water amount of secondary cooling to the product of the casting blank section size and the pulling speed is controlled to be smaller than or equal to 0.0075; and according to the proportion of the water amount of each segment in the total water amount, the foot roller area accounts for 10%-15%, the zero segment area accounts for 35%-45%, the arc-shaped segment area accounts for 25%-35%, and the straightening area accounts for 5%-10%. According to the control method for the corner cracks of the boron-containing steel plate slabs, the straightening temperature rises, the corner cross cracks are eliminated, and the hot-rolled coiled plate edge portion surface warping defect occurrence rate caused by the corner cross cracks of the plate slabs is reduced to 0.2% or below from 3%.
Owner:INST OF RES OF IRON & STEEL JIANGSU PROVINCE

Laser welding method for ultrasonic vibration along with welding

The invention relates to a laser welding method for ultrasonic vibration along with welding, and belongs to the field of welding. According to the method, preheating is applied in the welding process,and ultrasonic vibration is applied to the front side of a weld joint at a certain distance behind a molten pool; a corresponding relation exists between the preheating temperature T and the distanced from the top end of an ultrasonic head to the welding position, wherein the relation expression is as follows: T is equal to 30d-40, the unit T is DEG C, and the unit d is mm; and the position, thepower and the force of ultrasonic application are adjusted according to the mechanical property of materials under the preheating temperature. According to the laser welding method, the welding residual stress can be effectively reduced, pores and cracks are reduced, and thus the fatigue performance of the weld joint is improved, and the welding deformation is reduced. By adopting the method, thetemperature gradient in the cooling process can be effectively reduced, and the residual stress is reduced; and the plasticity of the ultrasonic application area can be improved, and the ultrasonic effect is better. The ultrasonic impact can effectively reduce residual stress, refine crystal grains and reduce pores and cracks, and thus the fatigue performance of the weld joint is improved; and the metal plastic extension of the weld joint can effectively reduce the welding deformation.
Owner:DALIAN UNIV OF TECH

Riveting pressing forming device for cover plate of automobile clutch booster

ActiveCN102430655AReduce stress concentrationAvoid early damageClutchEngineering
The invention discloses a riveting pressing forming device for a cover plate of an automobile clutch booster. The riveting pressing forming device for the cover plate of the automobile clutch booster comprises a base plate, wherein a positioning base is arranged on the base plate; a positioning cylinder is arranged rightly opposite to the positioning base; a pressing block is arranged on the positioning cylinder; a riveting cylinder is arranged on the base plate; the output end of the riveting cylinder is connected with the riveting assembly; a pressing cylinder is arranged below the base plate of the corresponding riveting cylinder; the output end of the pressing cylinder is connected with the pressing assembly; the riveting assembly comprises an installing base and a hinging pressing head; the installing base is fixedly installed on the base plate; the hinging pressing head are hinged with the installing base and the output end of the riveting cylinder; an installing plate is fixedly arranged on the base plate; the end part of the riveting cylinder is hinged with the installing plate; the pressing assembly comprises a pressing plate; the pressing plate is fixedly connected with the output end of the pressing cylinder vertically; and the pressing cylinder is fixed below the base plate through a fixing plate. The riveting pressing forming device for the cover plate of the automobile clutch booster has good riveting quality; in the riveting process, the damage to an electrophoretic paint layer at a cover plate forming position is avoided; the consistency of products is good; and the production efficiency is high.
Owner:ZHEJIANG KELI VEHICLE CONTROL SYST

Truck-frame side beam and crossbeam connecting joint totally-butted structure and assembly-welding process method

InactiveCN101973282AReduce stress concentrationRealize full butt connectionArc welding apparatusBogiesTruckWelding residual stress
The invention relates to a truck-frame side beam and crossbeam connecting joint totally-butted structure which is characterized in that the totally-butted connection of a side beam and a crossbeam is realized through a connecting seat, a plate-plate butt-joint structure is formed by a side beam connecting end and a side beam inner vertical plate, and a pipe-pipe butt-joint structure is formed by a crossbeam connecting end and the crossbeam. A assembly-welding process method comprises the assembly welding of the connecting seat and a crossbeam pipe, the assembly welding of crossbeam composition, the assembly welding of the connecting seat and the side beam inner vertical plate as well as a guide pole, the assembly welding of a side beam reinforcing baffle plate and an upper cover plate and the assembly welding of a whole frame. ,The invention realizes the totally-butted connection of the side beam and the crossbeam of the frame through a new connecting joint of the side beam and the crossbeam, breaks through a traditional process of forming the frame after both the side beam and the crossbeam become finished products, and has the advantage superior to the angle connecting structure or the angle-connecting and butting combined structure of a traditional structure and greatly superior to an overlapping structure. A welding joint has the minimum stress concentration, the minimum welding filling quantity and the minimum welding residual stress and deformation; the structural shape is continuous and attractive; and the bearing capacity and the anti-fatigue capacity are strong.
Owner:CRRC CHANGCHUN RAILWAY VEHICLES CO LTD

Method for assembling rubber dam in slope-shaped river channel

The invention relates to a method for assembling a rubber dam in a slope-shaped river channel. The method solves the long-existing problem of water leaking at the design height of the conventional slope-shaped rubber dam at present, improves unreasonable stress of dam bags and improves appearance of dam shapes. The method comprises the following steps of: 1) opening an upstream anchoring tank, a downstream anchoring tank and a top anchoring tank; 2) installing the bag edges of a downstream dam of the dam bag of the rubber dam; 3) installing the bag edges of an upstream dam of the dam bag of the rubber dam; 4) sealing both ends of the dam bag of the rubber dam, flatly overlaying ports on both ends of the dam bag, and placing the ports into the top anchoring tank; and 5) injecting water to the dam bag of the rubber dam from a water injection port to install the rubber dam. The method changes the structural form in the river channel after the rubber dam is installed, the slope part of the dam bag of the rubber dam extends downstream, cockles are formed at the positions of the horizontal section of the dam bottom and the slope section after the dam bag is aerated, and the cockles exist in downstream instead of the top of the dam bag in the conventional structure (the cockles are formed in the vertical direction).
Owner:JIANGSU YANGZHOU HELI RUBBER PROD

Three-dimensional stranding, untwisting and cabling machine for large-length great-section high-voltage photoelectric composite submarine cable

The invention discloses a three-dimensional stranding, untwisting and cabling machine for a large-length great-section high-voltage photoelectric composite submarine cable, which comprises a stranding rotating plate and a mechanical untwisting device of a supporting plate on the stranding rotating plate, the rotation of the stranding rotating plate is transmitted to the supporting plate through gears, and the supporting plate rotates by means of a mechanical swing bearing. The cabling machine also comprises a variable frequency motor, a PLC (Programmable Logic Controller) control system and an electrical untwisting device of an untwisting system, wherein the PLC control system controls the variable frequency motor to drive the supporting plate to rotate, the untwisting system is arranged above the supporting plate and detects the cable, the detection data is fed back to the PLC control system, the PLC control system compares the detection data with the set untwisting rate, the actual untwisting rate is obtained through comparison, and the deviation value is calculation so as to perform closed loop regulation to the variable frequency motor. The sufficient untwisting of each supporting plate untwisting device before cabling is realized through mechanical untwisting and electrical untwisting.
Owner:HENGTONG SUBMARINE POWER CABLE CO LTD +1

Assembled semi-rigid wood structure joint

InactiveCN104775528AGood carrying capacityReduce stress concentrationShock proofingSteel platesDuctility
The invention discloses an assembled semi-rigid wood structure joint. The assembled semi-rigid wood structure joint comprises a component I, a component II, a bending connecting piece, a shear connecting piece, an assembling piece, a steel cushion plate and connecting bolts, wherein the component I is a wood component, the bending connecting piece and the shear connecting piece are fixedly arranged at the end portion of the component I by adopting a steel plate implanting manner, the bending connecting piece and the shear connecting piece are T-shaped steel, the surfaces of the parts thereof implanted into the wood member are vulcanized with rubber layers, the end portion of the component I is pre-grooved at a steel plate implanting position, and the bending connecting piece and the shear connecting piece are connected through the connecting bolts and the assembling piece; the end portion of the component I can be connected with the side surfaces and the end portion of the component II or can be connected with a concrete foundation. The joint disclosed by the invention has higher bending capacity, joint rigidity, energy dissipation capacity and ductility performance. The joint not only can guarantee the structure stability under small earthquakes, but also can realize the prevention of large deformation of the structure under large earthquakes and control structure damages, and realizes ideal effects of high bearing capacity, high energy dissipation capacity and high ductility.
Owner:NANJING UNIV OF TECH
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