40results about How to "Reduce cracking damage" patented technology

The invention relates to a self-repairing cyanate ester resin system and a preparation method of the self-repairing cyanate ester resin system. The preparation method comprises the steps of adding vinyl terminated poly-p-phenylene oxide (PPO) resin with low molecular weight into a cyanate ester (CE) resin system, and using 4,4 phi-diamino diphenyl sulfone (DDS) as a catalyst to treat the CE / PPO resin system through low-temperature process to obtain the self-repairing cyanate ester resin system with high performance. According to the technical scheme, the vinyl terminated PPO is utilized for maintaining thermoplasticity of the CE during forming; after the cured CE resin system is damaged, the PPO ingredients can be melted and flow to fill a crack to realize material repairing through a heating system, therefore, the vinyl terminated PPO has positive effects on prolonging the service life of the material and improving the safety of the material; the resin system can be used for preparing high-performance composite materials, electronic devices and the like for aerospace construction.

The invention discloses a swing self-reset bridge bent frame with a ductility replaceable collar beam. The swing self-reset bridge bent frame with the ductility replaceable collar beam comprises a bridge foundation, a prefabricated cover beam and two prefabricated piers, wherein the prefabricated piers are arranged on the bridge foundation and used for supporting the left side and the right side of the prefabricated cover beam. The swing self-reset bridge bent frame with the ductility replaceable collar beam further comprises the replaceable collar beam transversely arranged between the two prefabricated piers. Unbonded prestress tendons are longitudinally arranged in the prefabricated piers. The two ends of each unbonded prestress tendon extend out of the upper end and the lower end of the corresponding prefabricated pier and are fixedly connected with the prefabricated cover beam and the bridge foundation respectively. The junction between each prefabricated pier and the prefabricated cover beam is provided with a shear key for connection, and is also provided with an energy dissipation longitudinal bar fixedly connected with the prefabricated pier and the prefabricated cover beam respectively. By the adoption of the technical scheme, the prefabricated parts are assembled rapidly, the overall structure is stable by means of the junctions, the replaceable collar beam and the unbonded prestress tendons, and the swing self-reset bridge bent frame has the swing and self-reset structural characteristic.

The invention discloses a novel swing type double-deck bridge bent frame which comprises a bent frame foundation, a group of bottom prefabricated bridge piers, a bottom prefabricated cover beam, a group of top prefabricated bridge piers, a top prefabricated cover beam, unbonded prestressing tendons, buckling-restrained braces and steel connecting pieces, wherein the bottom prefabricated bridge piers are respectively arranged at the left end and the right end of the bent frame foundation, and the bottom prefabricated cover beam is arranged at the top ends of the bottom prefabricated bridge piers; the top prefabricated bridge piers are respectively arranged at the left end and the right end of the bottom prefabricated cover beam, and the top prefabricated cover beam is arranged at the top ends of the top prefabricated bridge piers; the unbonded prestressing tendons penetrate through the two ends of the bottom prefabricated bridge piers, are respectively connected with the bent frame foundation and the bottom prefabricated cover beam and used for providing self-restoring capacity for the bent frame; the buckling-restrained braces are arranged between the bottom prefabricated cover beam and the bent frame foundation and used for providing main transverse stiffness and energy-dissipating capacity. The design of the double-deck bridge bent frame realizes the idea of functional separation, and the vertical bearing capacity of the bent frame is born by the prefabricated bridge piers and the prefabricated cover beams under a normal service condition. The transverse bridge stiffness and the energy-dissipating capacity of the bent frame are mainly born by the buckling-restrained braces under the action of an earthquake.

The invention discloses a laser cladding device and a laser cladding method for a slender workpiece, comprising a gripper, a thimble, a telescopic preheating sleeve, a laser cladding nozzle, a first guide rail and a second guide rail; the gripper and a thimble Both ends of the workpiece are clamped; the laser cladding nozzle slides on the first guide rail; the telescopic preheating sleeve includes a multi-section heating cylinder whose diameter gradually decreases from the jaw to the thimble; the heating cylinder with the largest diameter is slidably connected by the first bracket On the first guide rail, the heating cylinder with the smallest diameter is slidably connected to the second guide rail through the second bracket; the telescopic preheating sleeve moves and shrinks synchronously with the movement of the laser cladding nozzle, so that the workpiece is always kept preheated before laser cladding. Thermal state; after the laser cladding of the workpiece is completed, the telescopic preheating sleeve moves in reverse and stretches to heat the workpiece; clamping first and then preheating protects the safety of workers during operation; workpiece preheating and heat treatment can effectively Control the residual stress of the cladding layer, reduce crack damage, and improve the quality of laser cladding.

When a domain inversion part is produced by means of electric field polling process, damage in the vicinity of the forward end of a comb electrode and deviation of width of each domain inversion part are to be reduced. A polarization domain inversion structure has polarization domain inversion parts is produced by electric field poling process using a comb electrode formed on one surface of a substrate of a ferroelectric single crystal and of a single domain, and the comb electrode has a plurality of electrode portions and feeding portion. Each of the electrode portions corresponds with each domain inversion part of the domain inversion structure. The electrode portion has a plurality of low resistance pieces arranged in a direction “F” intersecting the longitudinal direction “E” of the electrode portion and spaced apart with each other.

The invention relates to a method for improving the stability of a die-molded composite door panel, which comprises the following four steps of: 1, selecting materials, to be specific, selecting a piece of melamine decorative paper and a middle-density fiberboard as materials for producing the die-molded composite door panel; 2, softening the middle-density fiberboard by spring an ammonia or urea solution; 3, limiting the depth and height of patterned fluctuation as well as a curvature radius of the patterned fluctuation transition of a mold; and 4, selecting a hot press for simultaneously closing multiple layers, setting high temperature and low temperature for press plates of the hot press at intervals one by one in die molding, doing different arrangements on a pavement sequence of raw materials on a high-temperature press plate and a low-temperature press plate, and giving special parameters to a closing speed, pressure, pressure holding time and pressure reduction speed in the pressurizing process so as to solve the stress balance problem of the die-molded composite door panel on different aspects. According to the invention, a set of feasible method is provided to guarantee the flatness of the die-molded composite door panel, reduce the fracture damage and guarantee the product quality.

The invention relates to a material for a nylon elastic coupler knuckle pin of a rail wagon, which comprises the following components by weight percentage: 65-80% of nylon 1212, 5-20% of maleic anhydride grafted ethylene-propylene-diene terpolymer, 5-20% of maleic anhydride grafted polyethylene, 0.5-5% of nucleating agent P22, 0.5-5% of silicone, 0.1-1.5% of antioxygen H10, 0.1-2% of paraffin and 0.1-1% of special white oil. The material for the nylon elastic coupler knuckle pin of the rail wagon is a high-polymer elastic material with better elasticity and toughness; for the coupler knuckle pin of the rail wagon, which is made of the material, the contact among a coupler knuckle, the coupler knuckle pin and a coupler lug hole is changed to flexible collision from the original rigid collision, the coupler knuckle pin is further higher in tensile modulus, impact strength and abrasion resistance, and the abrasion and cracking of the coupler knuckle, coupler lug hole bushing and other components are reduced.

The invention discloses a novel earthquake damage control system for a thin-wall hollow pier. The novel earthquake damage control system comprises a pier base, a thin-wall hollow pier, high-tenacity fiber-enhanced cement-based composite material expanded sections, an unbonded prestressed tendon and steel energy consumption elements, wherein the thin-wall hollow pier is arranged on the upper end surface of the pier base, so that the torsional strength and the energy-dissipating capacity of the thin-wall pier are improved. The high-tenacity fiber-enhanced cement-based composite material expanded sections are arranged on the inner side and the outer side of the lower part of thin-wall hollow pier; a series of steel energy consumption elements are arranged in the thin-wall hollow pier along the pier height; the lower part of the unbonded prestressed tendon is anchored on the pier base; and the upper part of the unbonded prestressed tendon is anchored at the center of the first steel energy consumption element from bottom to top. By virtue of the unbonded prestressed tendon, the self-resetting capacity of the pier after the earthquake is provided; and the crack width of the pier after the earthquake is reduced. By virtue of the high-tenacity fiber-enhanced cement-based composite material expanded sections, the axis-compression ratio of the bottom section of the thin-wall hollow pier is reduced; the shear-bearing capacity and the anti-bending capacity of the thin-wall hollow pier are increased; and the steel energy consumption elements can be arranged as rapid exchange components, so that the repairability after the earthquake is increased.

The invention relates to the technical field of fixed buildings, in particular to a gravity type damping filling wall which comprises a frame structure, two brickworks arranged in the frame structure side by side, and prestress ribs located on the two sides of the two brickworks and crossed at the diagonal position of the frame structure. A steel groove support is arranged below each brickwork. The two ends of each steel groove support are connected with the ground through opposite supporting legs respectively. Slide grooves are formed in the supporting legs. V-shaped supports are arranged between every two opposite supporting legs. The two ends of each V-shaped support are arranged in the slide grooves of the corresponding supporting legs on the two sides. Slide wheels are arranged at the bottom ends of frame columns of the frame structure. The top ends of the prestress ribs are fixed to the upper portion of the frame structure. The bottom ends of the prestress ribs are wound around the slide wheels and fixed to the middles of the V-shaped supports on the corresponding sides. By stretching or releasing the prestress ribs, the field angles of the V-shaped supports are changed. The two brickworks in the frame structure deform in the lateral direction of the frame structure so as to vertically and oppositely move, and therefore energy consumption happens to a damping medium in the filling wall, and the risks of cracking breakage and plane outward collapse of the filling wall are reduced.

The invention discloses a semi-conductor packaging unit and a manufacturing method hereof, which provides a carrier plate, wherein, a plurality of metal blocks and a metallic layer for coating the metal blocks are formed on the carrier plate so as to electrically connect at least one semi-conductor to the metallic layer, and then a packaging colloid coating the semi-conductor chip is also formed on the metallic carrier plate, then, the carrier plate and the metal blocks are removed to form a plurality of grooves on the surface of the packaging colloid correspondingly. At the bottom surface and the side of the grooves are covered with a metallic layer so as to lead the conductive elements to be effectively positioned in the grooves and fully conjugated with the metallic layer.