30results about How to "Reduce tensile strain" patented technology

The invention relates to a prefabricated T-shaped beam and a method of building a continuous beam bridge by adopting the prefabricated T-shaped beams, and belongs to the field of bridge engineering. The T-shaped beam is an improved form of the conventional prefabricated T-shaped beam, and bottom flanges are additionally arranged at the ends, so that the cross sections of the ends are I-shaped. Longitudinal prestressed ducts are formed in the bottom flanges, and the longitudinal prestressed ducts are also formed in top plates of the ends. The bridge is formed in a manner that the prefabricated T-shaped beams are spliced, simply supported and then connected. Longitudinal prestress is tensioned on the bottom flanges, and negative bending moment prestress is tensioned on the top plates. Certain prestress is exerted on compressed zones at the bottoms, so that cracks under the effects of temperature and the like can be avoided. The compression areas of the bottom flanges are increased, the compressive strain of the compressed zones is decreased under the effect of negative bending moment, correspondingly, the tensile strain at the tops is also decreased and thus the possibility of cracking of the bridge deck can be lowered. As the cross sections of the ends are changed to be I-shaped, transportation and installation are convenient, and the construction of the continuous beam bridge is also convenient. The method of building the continuous beam is convenient to construct, and cracks of the top plates at pier top areas are favorably decreased.

The invention discloses a steel bridge deck pavement structure. The steel bridge deck pavement structure is simple and reasonable in structure, a flexible connecting piece is low in shearing rigidity, good in anti-fatigue performance and constant in pull-out capacity and shearing strength, initial shearing rigidity is low, shearing force is kept around one third of the strength with continuous sliding deformation, shearing force value of local fittings can be effectively lowered, stress of bridge deck pavement layer close to rigid pillars is improved, crushing destruction of the bridge deck pavement layer is effectively avoided, the problem about local cracking of the surface of the pavement layer is solved, assumption of common design at present is met, and multiple pavement diseases and problems existing in the steel bridge deck pavement layer at present can be effectively solved. The pavement method is easy and convenient to operate, the pavement layer paved by a steel fiber reinforced concrete layer and an asphalt concrete layer form an integral, tensile capacity is increased, thickness is increased, tensile stress and tensile strain of the surface of the pavement layer can be effectively reduced, and the problem about cracking of the surface of the pavement layer can be effectively solved.

The present invention discloses production process of cold bent steel sheet pile with raised preliminary shaft machining precision. The technological scheme of the present invention is that the cold bent steel sheet pile is produced with strip steel blank and through stepped bending deformation including final closed pass bending to form preliminary shaft. The process has high preliminary shaft machining precision and less cracking of preliminary shaft during bending deformation. The production process of the present invention may be applied widely in producing different types of cold bent steel sheet pile, especially U-shaped cold bent steel sheet pile.

The invention provides a polypropylene composition and a polypropylene material as well as an application thereof. The polypropylene composition comprises polypropylene, a nucleating agent and an antioxidant, wherein the nucleating agent comprises a crystal form alpha nucleating agent and a crystal form beta nucleating agent, the crystal form alpha nucleating agent is selected from one or more of an inorganic crystal form alpha nucleating agent, a sorbitol nucleating agent and an organic phosphate nucleating agent, and the crystal form beta nucleating agent is selected from one or more of a mixture of binary acid and an II Ath group of metal salts, a rare earth crystal form beta nucleating agent and an amide nucleating agent. The polypropylene material prepared from the polypropylene composition provided by the invention can be used for well integrating effects of relatively low tensile strain, relatively high tensile strength and relatively good heat resistance and long-term creeping strength, and has great industrial application prospects.

It relates to a extension workmanship supplementary method, stretching plate material into low end and high end materials with at least one rib being extended on the circumference of the low end material. It also provides a extension mold, with convex and concave mold are of the same shape with high end and low end and at least one boss at the surrounding area of the low end. In this way, it can supplement extension for low end material, strengthening deformation rigidity of it, eliminating partial wrinkling of the parts, reducing flowing resistance, increasing material's flow into high end material of the supplement piece to reduce the stress deformation of the material to eliminate breach.

A method and structure are provided for implementing manufacture of a printed circuit board (PCB) with one of an infrared (IR) reflective mask or a novel solder mask to minimize coefficient of thermal expansion (CTE) mismatch between PCB laminate and plated through hole (PTH) copper. At least one of an IR-reflective mask and a solder mask composition for use in IR reflow processes is created such that radiant heat is reflected away from the major portion of the PCB yet permitted to impinge upon the PTHs. The copper within the PTH expands due to radiant heating while the bulk laminate expansion is significantly reduced due to the reflected IR radiation. Consequently, the CTE mismatch is minimized and tensile strain of the copper in the PTH is reduced, providing enhanced reliability.

The invention discloses a flexible optical fiber ribbon optical cable with a large number of cores, which comprises a water blocking tape, a loose tube, an inner sheath, a middle sheath, and an outer sheath arranged from the inside to the outside, and the optical fiber ribbon matrix is ​​arranged on the loose tube Inside, multiple Kevlar fiber bundles are evenly arranged between the inner and outer walls of the loose tube. The invention can solve the technical problem that the existing large-core optical fiber ribbon cable cannot achieve extreme bending radius, and the tensile performance is poor at the same time, and because the strengthening core has a large bending internal stress in an extremely bending application environment, it will affect the optical cable. Structural integrity, and technical issues that may damage the optical fiber. The invention also discloses a middle sheath processing device for large-core flexible optical fiber ribbon cable, which includes an inner sheath, a driving screw, an auxiliary screw, galvanized straight steel wires, and a pair of pressing driving wheels engaged with each other.

The invention discloses a long-life flexible base asphalt pavement structure, which belongs to the technical field of pavement structures. The pavement structure includes from top to bottom: asphalt concrete upper layer, its thickness is 3~6cm; high modulus anti-rutting asphalt concrete middle layer, its thickness is 6~12cm; high modulus asphalt concrete lower layer, its thickness 8~16cm; anti-fatigue asphalt concrete layer, its thickness is 4~6cm; graded crushed stone base, its thickness is 10~16cm; reinforced graded crushed stone subbase, its thickness is 12~18cm; roadbed improvement soil layer . The long-life flexible base asphalt pavement structure of the present invention solves the disadvantages of inherent reflection cracks that have always existed, reduces the consumption of non-renewable resource gravel aggregates from the perspective of environment and resources, and overcomes the service life design and service state of asphalt pavement The assessment does not clarify the problem.

A buried semiconductor laser exhibiting a reduced dislocation of a contact layer is achieved. A buried semiconductor laser, comprising: an n-type indium phosphide (InP) substrate; an active layer disposed on the n-type InP substrate; block layers provided so as to bilaterally disposed on both sides of the active layer; a clad layer provided so as to cover the active layer and the block layers; and a p-type gallium indium arsenide (InGaAs) contact layer provided on the clad layer, wherein the p-type InGaAs contact layer has a compressive strain.

The invention discloses a horizontal sliding anti-seepage connection structure between a geomembrane and an asphalt concrete panel, which belongs to the field of water conservancy and hydropower engineering. The geomembrane of the present invention and the asphalt concrete panel are overlapped through a reinforced concrete connecting plate, and a horizontal sliding plastic water-stop material is arranged between the asphalt concrete panel and the reinforced concrete connecting plate, so that the anti-seepage joint can slide horizontally, and at the same time The contact part between the geomembrane and the reinforced concrete connecting plate is provided with an overfilled bulge to reduce the "clamp effect" caused by the local stress concentration of the geomembrane and ensure the reliability of the seepage prevention of the lap joint of the geomembrane.

The invention relates to a geotechnical grid used for highway subgrade reinforcement and its application method. The grid net is made of high-strength and high-modulus polyvinyl chloride polymer vertically and horizontally to enhance the tensile strength of the ribs; the outer layer of the grid is covered with Modified rubber coating, the rubber is mixed with anti-aging agent, antioxidant and light shielding agent and other masterbatches; the surface layer of the grid longitudinal and transverse ribs has circular embossed threads, and the grid mesh is circular to reduce stress concentration , to enhance the extensibility of the ribs; there are double-sided "strengthening columns" at the joints of the grid ribs to prevent the sliding between the soil and the grid, enhance the shear performance of the subgrade, balance the settlement, and prevent the grid from being pulled out of the subgrade. The invention has the advantages of high strength of polymer material, external coating of modified rubber, small creep, high tensile strength and low tensile strain; the circular mesh, tendon thread and "reinforcing column" are fully occluded with the soil, A space composite strengthening structure is formed, which improves the overall shear strength of the subgrade and the performance of balanced settlement.