Testing system and testing method for structure

• US 6,397,153 B1
• Filed: 06/25/1999
• Issued: 05/28/2002
• Est. Priority Date: 06/25/1998
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Inoue, Masahiko, Umekita, Kazuhiro, Horiuchi, Toshihiko, Yamagishi, Wataru, Momoi, Yasuyuki
• Primary Examiner(s): Hoff, Marc S.
• Assistant Examiner(s): VO, HIEN XUAN
• Application Number:
  US09/339,874
• Time in Patent Office: 1,068 Days
• Field of Search: 702/42,56,33,35,113 73/662,663,778,786,664 700/29,30,60,61
• US Class Current: 702/42
• CPC Class Codes: G01M 7/022 Vibration control arrangements, e.g. for generating random vibrations
• CPC Class Codes: G01M 7/06 Multidirectional test stands
• CPC Class Codes: G01V 1/01 Measuring or predicting earthquakes

Abstract

The present invention discloses a testing system and a testing method for a structure which tests a structure made of a test piece structure and a numerical model virtually connected to the structure. A simulated structure including a frame, an actuator and a reaction force measuring device is mounted on a foundation on which a shaking table is also mounted. Only the test piece structure is mounted on the shaking table. The motion of the shaking table 5 which is generated at the time of shaking the test piece structure using the shaking table and the actuator is measured by a shaking table motion measuring device, while the reaction force generated by the test piece structure is measured by a reaction force measuring device. Using these measured values and the numerical model stored in a digital computer, the motion of the test piece structure after a predetermined period for the motion of the simulated structure is calculated. The actuator and the shaking table are driven so as to make this calculated motion.

Claims

1. A testing system for testing a structure comprised of a partial structure and a numerical model virtually connected to the partial structure, the testing system comprising:

a shaking table on which the partial structure is mounted, a simulated structure including at least one actuator for shaking the partial structure and means for measuring a reaction force that the simulated structure receives from the shaken partial structure, and a digital computer which calculates a motion of the numerical model based on a measured value of the reaction force measuring means, and which generates a shaking signal based on the calculated result for at least one actuator, the shaking table and the simulated structure being mounted on a common foundation.

2. A testing system for a structure comprising:

a shaking table mounted on a foundation by way of a first actuator;

a simulated structure having at least one second actuator fixedly mounted on the foundation;

a reaction force measuring device to measure a reaction force generated by a test piece structure connected to the simulated structure;

a digital computer which stores a numerical model that is virtually connected to the test piece structure;

a controller to control the simulated structure, and a shaking table motion measuring device to measure motion of the shaking table.

3. A testing system for a structure according to claim 2, wherein the digital computer outputs a control signal based on outputs of the shaking table motion measuring device and the reaction force measuring device to the controller.

4. A testing system for a structure according to claim 2, wherein the digital computer calculates motion of said test piece structure based on outputs of the reaction force measuring device and the numerical model, the test system further comprising an adder which adds the calculated motion result and the output of the shaking table motion measuring device, and outputs an added result to the controller.

5. A testing method for testing a structure comprised of a partial structure and a numerical model virtually connected to the partial structure comprising:

mounting the partial structure on a shaking table and shaking the partial structure with an actuator which is fixedly mounted on a foundation on which the shaking table is mounted;

measuring a reaction force generated by the shaken partial structure and a displacement of the shaking table;

obtaining a motion of a joint between the numerical model and the partial structure after a predetermined period from time to time when the reaction force is measured, the obtained motion being based on the measured values of the shaking table; and

inputting a shaking signal to the actuator for making the obtained motion at the joint after the predetermined period, the actuator shaking the partial structure based on the signal.

6. A testing method for testing a structure made of a test piece mounted on a shaking table and a numerical model virtually connected to the test piece and stored in a digital computer, comprising:

shaking the test piece not only by shaking the shaking table but also with an actuator fixedly mounted on a foundation on which the shaking table is mounted;

measuring a reaction force generated by the test piece structure;

measuring a displacement of the shaking table;

inputting the measured value of the reaction force to the digital computer;

inputting the measured displacement of the shaking table to the digital computer;

calculating a relative motion of the structure to the shaking table after a predetermined period from a time when the reaction force is measured, from the measured value of the reaction force with reference to the numerical model;

calculating a relative motion of the structure to the foundation of the shaking table after the predetermined period from the time when the reaction force is measured, by adding the calculated result of the relative motion of the structure and the measured value of the displacement of the shaking table;

calculating a shaking signal to generate the relative motion obtained by the calculation of the previous calculation step;

outputting the shaking signal after the predetermined period from the time when the reaction force is measured; and

driving the actuator based on the shaking signal.

7. A testing method for a structure made of a test piece mounted on a shaking table and a numerical model virtually connected to the test piece and stored in a digital computer comprising:

shaking the test piece using the shaking table and an actuator fixedly mounted on a foundation on which said shaking table is mounted;

measuring a reaction force generated by the test piece and inputting the measured reaction force to the digital computer while a relative motion between the test piece and the shaking table after a predetermined period from the time when the reaction force is measured is calculated using the measured value of the reaction force with reference to the numerical model;

calculating a relative motion between test piece and the foundation for the shaking table after the predetermined period from the time when the reaction force is measured, by adding the calculated result of the relative motion of the test piece and a preliminary obtained displacement of the shaking table;

obtaining a shaking force to be given to the test piece for making the calculated motion after the predetermined period; and

generating the shaking force by the actuator.

8. A testing method for a structure according to claim 7, further including measuring a displacement of the shaking table at the time of measuring the reaction force and using the measured displacement as the preliminarily obtained displacement.

9. A testing method for a structure according to claim 7, further including prestoring the preliminary obtained displacement of the shaking table in the digital computer.