Abstract: A column and beam connection structure for connecting a steel H-beam to a column uses an external diaphragm. The external diaphragm includes a plurality of divided diaphragm segments such that each diaphragm segment has a column plate abutting on the column. A diaphragm segment which is arranged along the steel H-beam among the plurality of divided diaphragm segments has a beam plate installed in a flange of the steel H-beam. The beam plate has an end portion in which the column plate is provided. A joining surface between the diaphragm segments is placed in a vicinity of a corner portion of the column so that only the column plate of one of the diaphragm segments abuts on each column surface of the column. A joining member fastens to fix between the diaphragm segments such that contact pressure is applied from the column plates to the surface of the column.

Abstract: A column and beam connection structure for connecting a steel H-beam to a column uses an external diaphragm. The external diaphragm includes a plurality of divided diaphragm segments such that each diaphragm segment has a column plate abutting on the column. A diaphragm segment which is arranged along the steel H-beam among the plurality of divided diaphragm segments has a beam plate installed in a flange of the steel H-beam. The beam plate has an end portion in which the column plate is provided. A joining surface between the diaphragm segments is placed in a vicinity of a corner portion of the column so that only the column plate of one of the diaphragm segments abuts on each column surface of the column. A joining member fastens to fix between the diaphragm segments such that contact pressure is applied from the column plates to the surface of the column.

Abstract: In an embodiment of a steel sheet having high Young's modulus, the steel can include in terms of mass %, e.g., C: 0.0005 to 0.30%, Si: 2.3% or less, Mn: 2.7 to 5.0%, P: 0.15% or less, 0.015% or less, Mo: 0.15 to 1.5%, B: 0.0006 to 0.01%, and Al: 0.15% or less, with the remainder being Fe and unavoidable impurities. One or both of {110}<223> pole density and {110}<111> pole density in the ? sheet thickness layer can be 10 or more, and a Young's modulus in a rolling direction can be more than 230 GPa. Other embodiments can include, e.g., Mn: 0.1 to 5.0%, N: 0.01% or less, and one or more of Mo: 0.005 to 1.5%, Nb: 0.005 to 0.20%, Ti: at least 48/14×N (mass %) and 0.2% or less, and B: 0.0001 to 0.01%, at a total content of 0.015 to 1.91 mass %.

Abstract: In an embodiment of a steel sheet having high Young's modulus, the steel can include in terms of mass %, e.g., C: 0.0005 to 0.30%, Si: 2.3% or less, Mn: 2.7 to 5.0%, P: 0.15% or less, 0.015% or less, Mo: 0.15 to 1.5%, B: 0.0006 to 0.01%, and Al: 0.15% or less, with the remainder being Fe and unavoidable impurities. One or both of {110}<223> pole density and {110}<111> pole density in the ? sheet thickness layer can be 10 or more, and a Young's modulus in a rolling direction can be more than 230 GPa. Other embodiments can include, e.g., Mn: 0.1 to 5.0%, N: 0.01% or less, and one or more of Mo: 0.005 to 1.5%, Nb: 0.005 to 0.20%, Ti: at least 48/14×N (mass %) and 0.2% or less, and B: 0.0001 to 0.01%, at a total content of 0.015 to 1.91 mass %.

Abstract: One aspect of the steel sheet having high Young's modulus includes in terms of mass %, C: 0.0005 to 0.30%, Si: 2.5% or less, Mn: 2.7 to 5.0%, P: 0.15% or less, S: 0.015% or less, Mo: 0.15 to 1.5%, B: 0.0006 to 0.01%, and Al: 0.15% or less, with the remainder being Fe and unavoidable impurities, wherein one or both of {110}<223> pole density and {110}<111> pole density in the ? sheet thickness layer is 10 or more, and a Young's modulus in a rolling direction is more than 230 GPa. Another aspect of the steel sheet having high Young's modulus includes, in terms of mass %, C: 0.0005 to 0.30%, Si: 2.5% or less, Mn: 0.1 to 5.0%, P: 0.15% or less, S: 0.015% or less, Al: 0.15% or less, N: 0.01% or less, and further comprises one or two or more of Mo: 0.005 to 1.5%, Nb: 0.005 to 0.20%, Ti: at least 48/14×N (mass %) and 0.2% or less, and B: 0.0001 to 0.01%, at a total content of 0.015 to 1.

Abstract: One aspect of the steel sheet having high Young's modulus includes in terms of mass %, C: 0.0005 to 0.30%, Si: 2.5% or less, Mn: 2.7 to 5.0%, P: 0.15% or less, S: 0.015% or less, Mo: 0.15 to 1.5%, B: 0.0006 to 0.01%, and Al: 0.15% or less, with the remainder being Fe and unavoidable impurities, wherein one or both of {110}<223> pole density and {110}<111> pole density in the ? sheet thickness layer is 10 or more, and a Young's modulus in a rolling direction is more than 230 GPa. Another aspect of the steel sheet having high Young's modulus includes, in terms of mass %, C: 0.0005 to 0.30%, Si: 2.5% or less, Mn: 0.1 to 5.0%, P: 0.15% or less, S: 0.015% or less, Al: 0.15% or less, N: 0.01% or less, and further comprises one or two or more of Mo: 0.005 to 1.5%, Nb: 0.005 to 0.20%, Ti: at least 48/14×N (mass %) and 0.2% or less, and B: 0.0001 to 0.01%, at a total content of 0.015 to 1.

Abstract: The present invention provides a join structure comprised of a box section column and split T-section joined by a high strength bolt and a method of securing a nut to an inside of the box section column. The present invention further provides a Torque-Shear type high strength bolt tightly tightened by a controlled tension and a joining method of a steel member using that bolt. The join structure is comprised of a box section column, a split T-section attached to its outer surface, and a high strength bolt inserted from the outside of the split T-section and fastened with the nut. The nut is secured to the box section column by joining a sleeve secured to a washer formed integrally with the nut and a sleeve of a nut holding part from the outside of the column. The Torque-Shear type high strength bolt has a pintail for controlling the torque at its top.

Abstract: A join structure comprises a box section column and spit T-section joined by a high strength bolt and a method secures a nut to an inside of the box section column. A Torque-Shear type high strength bolt is tightly tightened by a controlled tension and a joining method of a steel member uses that bolt. The join structure is comprised of a box section column, a split T-section attached to its outer surface, and a high strength bolt inserted from the outside of the split T-section and fastened with the nut. The nut is secured to the box section column by joining a sleeve secured to a washer formed integrally with the nut and a sleeve of a nut holding part from the outside of the column. The Torque-Shear type high strength bolt has a pintail for controlling the torque at its top.

Abstract: A high strength bold superior in delayed fracture resistant property has a bolt tensile strength of 1200 N/mm2. A high strength bolt comprised of a head portion and shaft portion formed by a steel material, wherein the relation between a bolt tensile strength TS (N/mm2) and tempering temperature T (° C.) satisfies the following expression (1), the relation between the bolt tensile strength TS (N/mm2) and the carbon equivalent Ceq (%) calculated from the chemical composition of the steel material used for the high strength bolt satisfies the following expression (2), and the tensile strength of the bolt is refined to a range of 1200 N/mm2 to 1600 N/mm2 by quenching and tempering: TS?1.1T+850??(1) TS?550Ceq+1000??(2) where, C eq = C + ( Mn / 6 ) + ( Si / 24 ) + ( Ni / 40 ) + ( Cr / 5 ) + ( Mo / 4 ) + ( V / 14 ) .

Abstract: A bolt set is provided that is made of steel free from technical difficulties in production, inexpensive in production cost, and improved in fatigue strength by a simple configuration. More particularly, a bolt set made of steel in which a tensile fluctuation stress acts upon an external thread side, characterized by setting a pitch difference ?P(=Pf?Pm) between a pitch Pm of the external thread and a pitch Pf of the internal thread within a range of 0.5-0.8% based on a pitch P prescribed in JIS B 0205 of Japan Industrial Standard.

Abstract: The present invention provides a high-strength bolted connection structure for realizing a steel structure with no fire protection, which is capable of adequately assuring high-temperature strength of the connection in a high temperature region of 650° C., and which does not depend on a fire protection or protective structure using fire resistant material, wherein ultra-high-strength bolts having excellent fire resistance and excellent resistance to delayed fracture are used, which bolt have a tensile strength at room temperature (TS) of 1200 N/mm2 or higher, and satisfies the relation that the shear proof stress at high temperature of 650° C. (b&tgr;t) is not less than (coefficient of slip at room temperature (&mgr;)×design bolt tension (N0))/(safety factor for long term load (&ngr;)×cross-sectional area of bolt shank (bAs)).

Abstract: The present invention provides a high strength bolt superior in delayed fracture resistant property having a bolt tensile strength of 1200 N/mm2 or more and a steel material for the same.

Abstract: The present invention provides a join structure comprised of a box section column and split T-section joined by a high strength bolt and a method of securing a nut to an inside of the box section column. The present invention further provides a Torque-Shear type high strength bolt tightly tightened by a controlled tension and a joining method of a steel member using that bolt. The join structure is comprised of a box section column, a split T-section attached to its outer surface, and a high strength bolt inserted from the outside of the split T-section and fastened with the nut. The nut is secured to the box section column by joining a sleeve secured to a washer formed integrally with the nut and a sleeve of a nut holding part from the outside of the column.

Abstract: A prefastenable torque-shear bolt has a bolt cut with a thread adapted to engage a nut, and full-fastening and prefastening grips each having wrench-engaging surfaces. One end of the bolt continues to a first transition portion that is tapered like a truncated cone. The full-fastening grip extends from the first transition portion and a full-fastening break-off groove. One end of the full-fastening grip continues to a second transition portion tapered like a truncated cone. The prefastening grip extends from the second transition portion and a prefastening break-off groove. The effective area of the fracture surface of the prefastening break-off groove is smaller than that of the full-fastening break-off groove. A first burr that arises on the threaded portion side when the full-fastening break-off groove is formed by rolling is formed on the first transition portion, and the outside diameter of the first burr is smaller than the diameter of the thread bottom in the threaded portion.