Shimizu Construction Co., Ltd.

Sumitomo Metal Industries, Inc.

Yoshitaka Yabe

Hideo Shimizu

Kiyoshi Ikura

Masahiro Kato

Toshihiko Hirama

Fumio Ohtake

Toshio Uno

Mitsugu Kuramochi

Shinji Mase

Tomomi Kanemitsu

Takehiko Terada

Increasing use of thermo-mechanically treated high strength steels in construction projects has created a need for on-site inspection of welded joints by ultrasonic techniques. However, such steels are acoustically anisotropic, and corrections of test results for anisotropy, according to the traditional methodologies, require lengthy and complex preparation steps which are unsuitable for on-site testing. The present invention presents an automated quick and simple methodology, and a compact apparatus for determining the acoustic anisotropy in such materials. The apparatus is expected to lead to effective management of quality assurance not only in civil and architectural engineering projects but in heavy machinery and ship building industries.

Method for evaluation of acoustic anisotropy and measuring apparatus

The present invention provides an earthquake resistant multi-story building which is characterized by having an energy concentration story. The energy concentration story has an elasto-plastic force-displacement relationship regarding horizontal force and displacement. The force-displacement relationship is characterized in that: (a) stiffness in elastic range (F.sub.y /d.sub.y) is generally equal to an optimal stiffness of the same story according to an elastic design concept; (b) the yield strength F.sub.y is generally less than 80% of an optimum yield strength; (c) stiffness in plastic range is positive and generally less than about a half of the stiffness in the elastic range; and (d) ultimate displacement is generally at least twice as large as the yield displacement. The energy concentration story is capable of entering into the plastic range while other stories are in the elastic range, and absorbing vibration energy by plastic deformations thereof so as to decrease deformations of other stories when a large external force is exerted to the building.

Earthquake resistant multi-story building

Growing community of inventors

Tokyo, Japan

Yoshitaka Yabe