Abstract: The floating body structure is a floating body structure that supports an object to be supported so that the object to be supported floats in the sea, including a floating body section connected to a base end portion of the object to be supported, wherein the floating body section has a lid body made of steel, an outer pipe made of steel, and an inner pipe made of steel and provided inside the outer pipe, and the floating body section is hermetically sealed by the lid body in a state where at least a portion of a gap formed between an outer wall surface of the inner pipe and an inner wall surface of the outer pipe is filled with concrete or mortar.

Abstract: The floating body structure is a floating body structure that supports an object to be supported so that the object to be supported floats in the sea, including a floating body section connected to a base end portion of the object to be supported, wherein the floating body section has a lid body made of steel, an outer pipe made of steel, and an inner pipe made of steel and provided inside the outer pipe, and the floating body section is hermetically sealed by the lid body in a state where at least a portion of a gap formed between an outer wall surface of the inner pipe and an inner wall surface of the outer pipe is filled with concrete or mortar.

Abstract: A method of production of a metallic product with a nanocrystallized surface layer comprising subjecting a surface layer of a metallic product to ultrasonic impact treatment by one or more ultrasonic indenters vibrating in a plurality of directions, then subjecting the surface layer subjected to the ultrasonic impact treatment to heat treatment at a low temperature to cause precipitation of nanocrystals.

Abstract: A novel treatment method, for improving fatigue life, is provided that aims to resolve problems associated with conventional treatment methods for improving fatigue life of metal by reduction of stress concentration and conventional treatment methods for improving fatigue life of metal by introduction of compressive stress, that is, problems of poor efficiency in work execution, required level of skill of workers, and the impossibility of quality control due to lack of means for measuring the effect after treatment, characterized in that, for locations in metal for which fatigue is a problem, after pre-treatment is performed, ultrasonic impact treatment is performed, and thereafter, a quality assurance test is performed so as to improve the fatigue life of the metal.

Abstract: A method of production of a metallic product with a nanocrystallized surface layer comprising subjecting a surface layer of a metallic product to ultrasonic impact treatment by one or more ultrasonic indenters vibrating in a plurality of directions, then subjecting the surface layer subjected to the ultrasonic impact treatment to heat treatment at a low temperature to cause precipitation of nanocrystals.

Abstract: A novel treatment method, for improving fatigue life, is provided that aims to resolve problems associated with conventional treatment methods for improving fatigue life of metal by reduction of stress concentration and conventional treatment methods for improving fatigue life of metal by introduction of compressive stress, that is, problems of poor efficiency in work execution, required level of skill of workers, and the impossibility of quality control due to lack of means for measuring the effect after treatment, characterized in that, for locations in metal for which fatigue is a problem, after pre-treatment is performed, ultrasonic impact treatment is performed, and thereafter, a quality assurance test is performed so as to improve the fatigue life of the metal.

Abstract: The present invention: provides a steel pipe pole base and a method for reinforcing the steel pipe pole base that do not allow the strength to lower in the vicinity of the weld toe of a rib even in the event of applying repeated bending moment; and is characterized by forming peening processed portions 20 by ultrasonic vibration at the weld toes 16 of tabular ribs 12 welded to the base of a steel pipe pole 10 in the form of a T-joint or the weld toes of inverted-U shaped ribs 13 or inverted-V shaped ribs 14, the ribs being bent at the upper end portions, welded to the base of a steel pipe pole 10 in the form of a T-joint. Preferable treatment conditions are 20 to 50 ?m in amplitude and 10 to 50 kHz in frequency. In particular, the present invention makes it possible to remarkably improve the fatigue property because stress concentration is relaxed by the synergetic effect of bending the upper end portions 16 of the ribs 13 and applying a peening treatment.