45results about How to "Avoid deformation stress" patented technology

The invention discloses a laser scanning method used for fast forming a high-temperature alloy structural member. The method comprises the following steps that (a), according to the geometric feature comprising the area S, the wall thickness H and the shape P and the precision requirement of the structural member, a geometric model of each layer is divided into a plurality of areas, scanning methods for the different areas are determined, and the rectangular-ambulatory-plane shape, the stripe shape and the chess board shape are involved in the scanning methods; (b), forming scanning is carried out, the different areas in each layer are sequentially scanned, and the structural member is formed; (c), the outer surface is scanned, the outer surface of the formed structural member is scanned for the second time, and fast repair and heat treatment on the outer surface of the structural member are realized. According to the method, all the slice layers are divided into areas, the different scanning methods are selected, and therefore the problems of stress deforming and cracking caused by heat concentration are effectively avoided; the mechanical property and the surface precision of the high-temperature alloy structural part fast formed are improved.

The invention relates to a method for forming a grating for machine tool measurement in a two-step solidifying rolling pressing forming manner, which comprises the following steps: 1) coating an ultraviolet light solidifying adhesive layer on a grating blank substrate; 2) manufacturing a rolling mould having a prototype grating structure on the surface of a cylindrical mould, making an alignment mark, and polishing and performing low surface energy treatment on the surface of the rolling mould; 3) coating a flexible film on the adhesive layer on the grating blank substrate, carrying out primary exposure and peeling the film; 4) comparing the alignment mark on the grating blank substrate with an acquired alignment mark image on the surface of the rolling mould, adjusting and calibrating; 5) gluing the rolling mould with the grating, applying a pressing force, and compounding the prototype grating structure on the surface of rolling mould on the adhesive layer on the surface of the substrate; 6) carrying out exposure on the compounded ultraviolet light solidifying adhesive layer; and 7) collecting and packaging the grating. According to the method, the required pressing force is small, and thus, the substrate deformation and stress concentration are avoided. The method has high production efficiency and can be used for realizing the mass production of the grating for large-area and altitude machine tool measurement.

The invention provides a novel prefabricated type steel-concrete composite beam bridge upper structure comprising main steel beams, transverse connecting steel beams, metal connecting pieces and prefabricated reinforced concrete bridge deck slabs. The main steel beams are arranged according the shape of a bridge. The webs of the adjacent main steel beams are connected through the transverse connecting steel beams. The upper flanges of the main steel beams are provided with the metal connecting pieces. The prefabricated reinforced concrete bridge deck slabs are laid on the upper flanges of the main steel beams and provided with preformed holes used for grouting of grouting materials after the bridge deck slabs are well installed. The metal connecting pieces are located in the preformed holes. The invention further provides a manufacturing technology of the novel prefabricated type steel-concrete composite beam bridge upper structure. By the adoption of the novel prefabricated type steel-concrete composite beam bridge upper structure and the manufacturing technology of the novel prefabricated type steel-concrete composite beam bridge upper structure, damaged medium and small span concrete beam bridges can be rapidly replaced, the structure safety is good, the construction period is short, the cost is low, and the durability is good.

The invention discloses a construction method of a suspended steel gallery. The suspended steel gallery is connected between main body structures; a preassembled bar is firstly arranged at designed elevation of the suspended steel gallery, a lifting platform is arranged, and meanwhile, a hydraulic lifter is arranged; an upper truss structure of the suspended steel gallery is spliced on the ground, the hydraulic lifter is debugged to lift in a segmented manner, wherein the lifting height of each time is the height of one layer of suspended structure; and the suspended steel gallery is lifted to the elevation for welding after assembly is completed. According to the method, one-time overall lifting method of the multi-layer suspended steel gallery is changed into a hydraulic multi-time segmented lifting method, so that large-range reinforcement of a basement roof is avoided, the construction period is shortened, the cost is reduced, the designed mechanical principle is matched and stress deformation and internal stress generation of a suspended structure are avoided. The appearance quality of the steel gallery and the quality of a welding line and a member meet the national current acceptance standard requirements; and the design idea is achieved.

A construction method for integrally hoisting a large-size multi-edge-and-corner overhanging truss is disclosed. Integral assembling of a steel pipe truss is conducted on site, and integral hoisting is conducted after assembling is completed; the truss is connected with three welding positions in a butt-joint mode and then is welded firmly; two 500 t all-terrain cranes and a 350 t all-terrain crane are adopted to hoist the whole truss simultaneously, and step-by-step hoisting is conducted from south to north; the truss is totally provided with three main stress support joints which are all fixed by adopting butt welding, a third calibration point support is located at the top of the truss, a welded ball joint at the position of the third calibration point is a support point of a steel rainshed grid frame actually, a first calibration point support and a second calibration point support are located on both the left and right sides of the bottom of the truss correspondingly, and the first calibration point support and the second calibration point support are global stress supporting points of the truss. The construction method for integrally hoisting the large-size multi-edge-and-corner overhanging truss has the characteristics that the construction safety is high, the construction period is short, the engineering quality is easy to guarantee, the ground integral assembling efficiency is high, and the construction cost is reduced greatly.

The invention relates to a method for preventing hot working warpage and deformation of large titanium alloy isothermal precise thin web plate forge pieces. The method is characterized by comprising the following steps of: taking isothermal precise forge pieces out of a high-temperature forging mould, and then hanging the forge pieces on a bracket for air cooling; and before heat treatment in a furnace, flatly placing forge pieces with warpage on base plates, and putting cushion blocks between the forge pieces and base plates and firmly padding, wherein if the bottom surfaces of the forge pieces are parallel and have equal height, the heights of the cushion blocks are consistent, and if the bottom surface of the forge pieces have height falls, the heights of the cushion blocks have identical falls. By adopting the method, heat in the processes of cooling after isothermal forging and cooling after heat treatment of large complicated titanium alloy plane structures with unequal cross section areas is uniformly dispersed, and the forge piece warpage parts are pressed flatly in the heat treatment process. The process provided by the invention has the advantages of simplicity, easiness in application and low cost.

The invention relates to a steel-concrete partially-prefabricated composite beam structure using layered perforated plate connecting pieces. The steel-concrete partially-prefabricated composite beam structure using the layered perforated plate connecting pieces comprises steel main beams, transverse connecting steel plates, perforated plate connecting pieces, prefabricated portion slabs and cast-in-situ portion slabs, wherein the perforated plate connecting pieces are arranged on upper flanges of the steel main beams, an upper row of openings and a lower row of openings are formed in the perforated plate connecting pieces, the transverse connecting steel plates are connected between webs of adjacent steel main beams, the prefabricated portion slabs are located on the upper flanges of the steel main beams, the perforated plate connecting pieces are exposed out of the prefabricated portion slabs, the lower row of openings are located in the prefabricated portion slab, the upper row of openings are located above the prefabricated portion slabs, the cast-in-situ portion slabs are located on the prefabricated portion slabs, and the upper row of openings are located in the cast-in-situ portion slabs. The invention further provides a manufacturing process of a steel-concrete partially-prefabricated composite beam structure using layered perforated plate connecting pieces. The steel-concrete partially-prefabricated composite beam structure using the layered perforated plate connecting pieces and the manufacturing process have the advantages that the replacement time of a bridge superstructure can be greatly reduced, the construction period is shortened and the urban traffic pressure is greatly relieved; and the mass of the bridge superstructure is reduced.

The invention discloses a rail wagon corner post assembly welding deformation control device. The rail wagon corner post assembly welding deformation control device comprises a workbench, a middle turning over and positioning mechanism is arranged in the middle of the workbench, the two ends of the workbench are each provided with an end part turning over and positioning mechanism and an oil cylinder pressing mechanism, the middle turning over and positioning mechanism and the two end part turning over and positioning mechanisms are provided with the same turning over and positioning assemblies, and the turning over and positioning assemblies are in follow-up connection through an turning over horizontal base plate arranged in the length direction of the workbench, the turning over and positioning assemblies are arranged on the turning over horizontal base plate through deflection inserts, and a plurality of spring type conveying rollers are arranged on the turning over horizontal base plate at intervals. According to the rail wagon corner post assembly welding deformation control device, deflection reversible deformation can be prefabricated on a welding part in advance, the deformation stress of the part in the welding process is counteracted, by arranging a turning over device, the deflection inserts and the spring type conveying rollers, the labor intensity in the conveying process can be relieved, deflection reversible deformation can be automatically prefabricated, all the systems are fused and assembled on the workbench to form a combined integrated structure, and the working efficiency is improved.

Concrete upper ribs and floors of a novel steel-concrete combined open web girder system are made of cast-in-place concrete and form an orthogonal cross shape; holes are formed in reverse T-shaped joints of combined components so that concrete can be conveniently cast into the holes and shear connectors can be formed; reverse T-shaped steel pipes and U-shaped steel plates are all prefabricated in a factory, in the use process, the U-shaped steel plates penetrate through reserved holes in the bottoms of the reverse T-shaped steel pipes, and the T-shaped steel pipes and the U-shaped steel plates are positioned through high-strength bolts of bottom plates, and concrete is cast into the shear connectors into a whole. The system has the advantages that the structural deadweight is reduced, and rigidity is less reduced; the size of the shear connectors is reduced, and the rigidity of the shear connectors is improved; tensile force is borne by the square steel pipes, the steel pipes participate in shear resistance at the joint shear connectors, and the mechanical performance of materials is brought into full play; no welding or formworks are needed, welding stress and deformation are avoided, construction procedures are reduced, and construction efficiency is greatly improved.

The invention discloses a new-type hinge expansion joint for a high-temperature flue of a flue gas turbine. The new-type hinge expansion joint comprises a pipe nipple I, a pipe nipple II, a corrugatedpipe, a load-bearing frame I, a load-bearing frame II, two sets of hinge mechanisms and eight sets of support assemblies, wherein the pipe nipple I, the corrugated pipe and the pipe nipple II are connected in sequence; the load-bearing frame I is located on the side where the pipe nipple I is located and supports the pipe nipple I through four of the sets of support assemblies; the load-bearing frame II is located on the side where the pipe nipple II is located and supports the pipe nipple II through the other four sets of support assemblies; and the two sets of hinge mechanisms are mounted between the load-bearing frame I and the load-bearing frame II. The invention ensures the persistent working of the expansion joint under high temperature, thereby prolonging the service life of the product.

The invention discloses a double-steel-plate concrete composite shear wall with U-shaped pull rods arranged in a staggered mode, and belongs to the technical field of civil engineering composite structures. The double-steel-plate concrete composite shear wall is mainly used for solving the problems of large welding deformation of external steel plates, difficulty in controlling welding residual stress, complexity in bolt perforation and the like in the prior art. The double-steel-plate concrete composite shear wall with the U-shaped pull rods arranged in the staggered mode is mainly composed of steel plates with holes in the two sides, the U-shaped pull rods, internal positioning nuts, external fixing nuts and filling concrete, wherein the U-shaped pull rods are metal products with good ductility such as a rebar, a screw rod, a steel bar and is in a U shape through cold machining, the end parts of the U-shaped pull rods are provided with threads capable of installing a bolt, and the U-shaped pull rods at adjacent positions of the steel plates on the two sides are staggered. Bolt connection is adopted, a large amount of welding work is avoided, welding deformation and welding residual stress do not exist, the outer steel plate can keep higher flatness, the staggered pull rods are large in contact area with concrete and small in shearing slippage, certain constraint can be provided for filling of the concrete, and the cooperative work capacity of the steel plates and the concrete is improved.

The invention discloses an integrated liquid rocket engine thrust chamber top cover structure, and belongs to the technical field of machinery. The top cover comprises a force bearing end face, a propellant inlet bent pipe, a propellant inlet flange, a top cover inner cavity, an inner conical surface, an outer conical surface, a top cover bottom surface and a force bearing wall. Thrust generated by a thrust chamber of the liquid rocket engine is transmitted to the top cover from the bottom face of the top cover, transmitted to the force bearing wall through a triangular force bearing structure formed by the inner conical face and the outer conical face and finally transmitted to an engine rack through the force bearing end face. Propellant enters the top cover from a propellant inlet in the propellant inlet flange, flows through the propellant inlet bent pipe, enters the inner cavity of the top cover and then enters the downstream nozzle.