NATURAL FREQUENCY IDENTIFICATION DEVICE AND NATURAL FREQUENCY IDENTIFICATION METHOD

• Main Authors: NAITO NAOTO, KEYAKI TAKENORI, YUASA TOMOKI, WATANABE SATOSHI
• Format: Patent
• Language: English; Japanese
• Published: 19.09.2019
• Subjects: MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC ORINFRASONIC WAVES; MEASURING; PHYSICS; TESTING; TESTING STATIC OR DYNAMIC BALANCE OF MACHINES ORSTRUCTURES; TESTING STRUCTURES OR APPARATUS NOT OTHERWISE PROVIDED FOR

To provide a natural frequency specifying device and a natural frequency specifying method based on fine motion that can reduce a cost of a detection unit while maintaining the accuracy of natural frequency identification with a wide range of applications.SOLUTION: The amplitude ratio calculation unit 32 which computes a ratio of an amplitude of a Fourier transformation of a horizontal vibration of the structure 1 detected by the sensor 11a, and an amplitude of the Fourier transformation of vibration of the foundation 3 computed by the ground shaking calculation unit 31, a theoretical amplitude ratio calculation unit 33 which computes a parameter at the time of applying the ratio computed by the amplitude ratio calculation unit 32 to the theoretical figure of the ratio, and a coefficient-of-determination calculation unit 34 which computes the coefficient of determination between the ratio computed by the amplitude ratio calculation unit 32 and the theoretical figure of the ratio, and the character frequency specifying unit 35 which specifies the character frequency based on a coefficient of determination computed by the parameters computed by the theoretical amplitude ratio calculation unit 33 and the coefficient-of-determination computed by the coefficient-of-determination calculation unit 34.SELECTED DRAWING: Figure 1 【課題】微動をもとにした手法であって、適用範囲が広くかつ固有振動数同定の精度を維持しつつ、検出部のコスト削減を図ることができる固有振動数特定装置及び固有振動数特定方法を提供する。【解決手段】センサ１１ａにより検出された構造物１の水平方向の振動のフーリエ変換の振幅と地盤振動算出部３１により算出された地盤３の振動のフーリエ変換の振幅との比を算出する振幅比算出部３２と、振幅比算出部３２により算出された比を比の理論値にあてはめた際のパラメータを算出する理論振幅比算出部３３と、振幅比算出部３２により算出された比と比の理論値との間の決定係数を算出する決定係数算出部３４と、理論振幅比算出部３３により算出されたパラメータ及び決定係数算出部３４により算出された決定係数に基づいて固有振動数を特定する固有振動数特定部３５とを有する。【選択図】図１