JP6562551B2 - Structure damage detection method and system - Google Patents

Description

  The present invention relates to a structure damage detection method and system, and more particularly to a method and system for detecting damage caused to a structural member during an earthquake.

  A structure damaged by an earthquake (such as a building) may cause secondary damage due to an aftershock because the damage is large, but a resident may evacuate from fear even though the damage is small. is there. In order to reduce both secondary damage and evacuees, it is necessary to quickly detect damage to structures after an earthquake. 2. Description of the Related Art Conventionally, a method in which a specialized engineer visually observes structural members such as pillars and beams of a structure after an earthquake has been carried out to determine damage. However, damage to members is often not easily visible due to fireproof coating or the like, and it has been pointed out that this method takes time to determine damage (see Non-Patent Document 1).

  In place of the conventional visual damage judgment method, sensors (for example, displacement gauges) that monitor behavior in advance are attached to a plurality of predetermined sites where damage to the structure is a concern. A method for determining the damage in real time has been proposed (see Patent Documents 1 to 3). In addition, an elastic response analysis model of the structure is set in advance and a sensor (for example, a displacement meter) is installed at a predetermined location on the structure, and simulation using the elastic response analysis model is performed from the output information of the measurement sensor during an earthquake. There has been proposed a method for determining damage to a structural member or an entire structure in real time (see Patent Documents 4 to 5).

On the other hand, a method of reducing damage to a structure by attaching a piezoelectric device to the structural member of the structure and absorbing the seismic energy applied to the structure by the piezoelectric device to attenuate (actuate a damping force). Has been proposed (see Patent Documents 6 to 7). Generally, the total energy E of the earthquake applied to the structure is balanced with the sum of the elastic vibration energy We, the cumulative plastic strain energy Wp, and the energy absorption amount Wh due to the damping as shown in the equation (1) (non-patent) Reference 2). Among them, the elastic deformation of the structure is released after the earthquake converges and returns to the unstrained state, but the plastic deformation accumulates until it breaks without being released, so damage to the structure after the earthquake damage (1 This corresponds to the accumulated plastic strain energy Wp in the equation (1). Piezoelectric devices absorb energy by converting seismic energy (force) into electrical energy (electric charge), thereby increasing energy absorption amount Wh in equation (1) and reducing accumulated plastic strain energy Wp. It can be considered as a mechanism (seismic control mechanism).
E = We + Wp + Wh …………………………………………………………… (1)

JP 2000-186944 A JP 2004-037351 A Japanese Patent Laid-Open No. 2007-039879 JP 2012-083172 A JP 2014-122866 A Japanese Patent Laid-Open No. 10-061708 Japanese Patent Laying-Open No. 2015-048894 JP 2006-166661 A

Koichi Tsuji "Evaluation of residual seismic performance of buildings after earthquake" Concrete Engineering, Vol. 44, no. 5, May 2006, Internet <https: // www. jstage. jst. go. jp / article / coj1975 / 44/5 / 44_102 / _pdf> Hiroshi Akiyama “Aseismic Design of Buildings Based on Energy Balance”, Gihodo Publishing, November 26, 1999

  However, the damage determination method for monitoring the behavior of a structure during an earthquake described above requires the installation of a huge number of monitoring sensors in order to detect damage to various members constituting the structure. However, there is a problem that it is not possible to monitor all the parts that are likely to be damaged from an economic point of view. It is difficult to detect damage to the entire structure with sufficient accuracy by monitoring only a limited area. On the other hand, the structural damage determination method based on the above-mentioned simulation has the advantage of being able to detect the damage of a member where no sensor is installed by a measurement sensor in a limited area. There is a problem that requires a lot of time and cost for setting, and damage detection accuracy tends to be lower than that of the monitoring method. It is desirable to introduce damage judgment in the event of an earthquake to a general structure that does not have an analysis model or the like. Development of technology that can detect economically accurately is desired.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a method and system that can economically and accurately detect damage caused to a structural member during an earthquake.

  The inventor has focused on the piezoelectric device used as the above-described energy absorption type vibration damping mechanism. As shown in the vibration model of FIG. 6A, a general vibration damping device 60 such as a brace material is mounted on the vibration damping device 60 in parallel with the main structural member of the structure 1. The force (load) is different from the force (load) applied to the structural member. On the other hand, since the piezoelectric device 20 can be directly sandwiched between the structural members of the structure 1 as shown in the vibration model of FIG. 6B, substantially all of the force (load) applied to the structural member is obtained. It can be applied directly to the piezoelectric device 20 and it can be expected to estimate the stress of the structural member from the output power of the piezoelectric device 20. In addition, in the case of the piezoelectric device 20, the output power can be used as a power source. Therefore, by incorporating the piezoelectric device 20 in a large number of parts where there is a risk of damage to the structure, various parts of the structure can be obtained without using external power. It is expected that damage can be detected in an energy independent manner. The present invention has been completed by research and development based on this idea.

Referring to the embodiment of FIG. 1, damage detection method of the structure according to the present invention, the piezoelectric device 20 joints of the structural member 2, 3 between the structural members 2 and 3 to be bonded to each other of the structure 1 The direction of the force applied to the piezoelectric device 20 and the pressurizing direction in which power proportional to the pressure of the piezoelectric device 20 is output are matched, and the output power P of the piezoelectric device 20 is input to the controller 30 provided with the power storage means 33. The controller 30 driven by the stored electric power P calculates the stress Q of the structural members 2 and 3 from the output voltage V of the piezoelectric device 20 (see FIG. 4A), and the time history of the stress Q ( Based on FIG. 4 (B)), damage to the structural members 2 and 3 is detected.

Further, referring to the block diagram of FIG. 1, the damage detection system for a structure according to the present invention is added between the structural members 2 and 3 of the structure 1 which are joined to each other, at the joint of the structural members 2 and 3. The piezoelectric device 20 sandwiched so that the direction of force and the pressurizing direction in which power proportional to the pressure is output, the power storage means 33 for inputting and storing the output power P of the piezoelectric device 20, and the power storage means 33 The driven member calculates the stress Q of the structural members 2 and 3 from the output voltage V of the piezoelectric device 20 (see FIG. 4A) and the structural member 2 based on the time history of the stress Q (see FIG. 4B). , 3 includes a controller 30 having detection means 36 for detecting damage.

  In the preferred embodiment, as shown in FIG. 1C, the controller 30 is provided with information communication means 38 that is driven by the power storage means 33 and outputs the stress calculation value Q of the structural members 2 and 3 to the external base station 50. . In a more preferred embodiment, as shown in FIGS. 1B and 1C, the measurement value δ is sent to the external base station 50 or the controller 30 by being attached to the structural members 2 and 3 and driven by the power via the controller 30. An output sensor 40 is provided, and the cumulative plasticity of the structural members 2 and 3 is determined from the time history of the stress Q of the structural members 2 and 3 and the measured value δ of the sensor 40 (see FIG. 7B) in the external base station 50 or the controller 30. A calculation means 37 for calculating the strain energy Wp is provided, and damage to the structural members 2 and 3 is detected based on the accumulated plastic strain energy Wp.

  The piezoelectric device 20 is replaced with or in addition to the structural members 2 and 3 of the structure 1 as shown in FIG. 1, and the structural members 2 and 3 of the structure 1 and the brace material 4 as shown in FIG. Or can be sandwiched between the structure 1 and the seismic isolation device 6 as shown in FIG.

The structure damage detection method and system according to the present invention includes the piezoelectric device 20 between the structural members 2 and 3 to be bonded to each other of the structure 1 and the direction of the force applied to the joint of the structural members 2 and 3 and the piezoelectric device. The electric power proportional to the pressure of 20 is sandwiched so as to coincide with the pressurizing direction, and the output power P of the piezoelectric device 20 is input to and stored in the controller 30 provided with the storage means 33 and the stored power The stress 30 of the structural members 2 and 3 is calculated from the output voltage V of the piezoelectric device 20 by the controller 30 driven by P, and the damage of the structural members 2 and 3 is detected based on the time history of the stress Q. Has an effect.

(A) Damage to the structural members 2 and 3 can be detected in real time using the output power P of the piezoelectric device 20 as a power source, and power supply cables and the like required for monitoring the conventional structural members 2 and 3 can be omitted. Therefore, the stress Q of the various structural members 2 and 3 of the structure 1 can be calculated independently of energy, and the presence or absence of damage can be detected economically.
(B) Further, by storing the output power P of the piezoelectric device 20 in the controller 30, it is possible to provide information communication energy to the external base station 50 of the stress calculation value Q of the structural members 2 and 3.

(C) Furthermore, by supplying the output power P of the piezoelectric device 20 to the sensor 40 attached to the structural members 2 and 3 via the controller 30, the time history of the stress Q of the various structural members 2 and 3 and the sensor 40 The cumulative plastic strain energy Wp of the structural members 2 and 3 is independently calculated from the time history of the displacement δ of the structural members 2 and 3 obtained from the measured value δ, and the soundness (limits) of various structural members 2 and 3 is calculated. It is possible to economically detect the margin) from the relationship with the performance.
(D) By combining the piezoelectric device 20 acting as an energy absorption type vibration damping mechanism with the controller 30, it is possible to realize a system that combines the three functions of a vibration damping function, a power generation function, and a damage monitoring function with a single device.

Hereinafter, embodiments and examples for carrying out the present invention will be described with reference to the accompanying drawings.
It is explanatory drawing of one Example of the damage detection system by this invention. 2 is a flowchart illustrating three functions of the damage detection system of FIG. 1. It is explanatory drawing of the other Example of the damage detection system by this invention. It is explanatory drawing of the method of calculating the stress Q of a structural member from the output electric power of a piezoelectric device, and the method of detecting the damage of a structural member from the time history of the stress Q. It is explanatory drawing of an example of the output electric power of the piezoelectric device inserted | pinched between the structural members of a structure. It is explanatory drawing of the difference with a piezoelectric device and another energy absorption type damping device. It is explanatory drawing of the method of calculating the cumulative plastic strain energy Wp of a structural member from the time history of the stress Q and displacement (delta) of a structural member.

  FIG. 1 shows an embodiment in which the damage detection system 10 of the present invention is applied to damage detection of a beam-column joint portion of a structure 1. The damage detection system 10 in the illustrated example includes a plurality of piezoelectric devices 20 sandwiched between structural members 2 and 3 (beam members 2 and column members 3) to be joined to each other, and outputs of the piezoelectric devices 20 as inputs. And a controller 30 for detecting a few damages. In the structure 1 in the illustrated example, a damage detection system 10 is incorporated in each of the column beam joints that are likely to be damaged, and each damage detection system 10 detects each damage of the corresponding column beam joint. The number and location where the damage detection system 10 is incorporated is not limited to the illustrated example.

  As shown in FIG. 1 (C), the damage status detected by the controller 30 of each damage detection system 10 is transmitted to a remote base station 50 in the structure 1 via a wireless or wired information communication path 59. The external base station 50 can record and manage the damage of each column beam joint of the structure 1 in the storage means 51. The external base station 60 can be provided at a point away from the structure 1 instead of inside the structure 1. However, the external base station 50 is not essential for the damage detection system of the present invention, and can also display and manage the damage status independently at each column beam joint.

  The piezoelectric device 20 in the illustrated example is a device that outputs a charge (power P) proportional to the pressure when a pressure in a predetermined pressurizing direction is applied, and can be made of, for example, lead zirconate titanate (PZT). . The force applied to the beam-column joint of the structure 1 directly acts on the piezoelectric device 20, that is, the direction of the force applied to the joint coincides with the predetermined pressing direction of the device 20 as shown in FIG. Thus, the piezoelectric device 20 is sandwiched between the beam member 2 and the column member 3. In addition, for example, the piezoelectric device 20 is fixed to the beam member 2 and the column member 3 with the required joint strength that does not separate even during an earthquake by the bolt 8 and the nut 9. In the illustrated example, the beam member 2 and the column member 3 are steel frames, the piezoelectric device 20 is incorporated so that the force applied to the beam flange 2a is directly applied to the piezoelectric device 20, and a high-strength bolt that can withstand the maximum load assumed in an earthquake disaster ( The piezoelectric device 20 is fixed to the beam member 2 and the column member 3 using a high tension bolt.

  As shown in FIG. 1C, the controller 30 in the illustrated example includes a power storage means 33 for continuously inputting and storing the output power P of the piezoelectric device 20, and the power P stored in the power storage means 33 in the controller 30. And a power supply means 34 for supplying power to the battery, and is driven by the power storage means 33. For example, the power supply means 34 can supply the power of the power storage means 33 after performing necessary voltage adjustment. By driving the controller 30 with the output power P of the piezoelectric device 20, it is possible to make the damage detection system 10 an energy self-supporting device that does not require external power supply.

  Further, the controller 30 in the illustrated example calculates the stress Q of the structural members 2 and 3 from the measurement means 32 that measures the current value I and voltage value V of the output power P of the piezoelectric device 20 and the output voltage V of the piezoelectric device 20. Then, there is a detection means 36 for detecting damage and an information communication means 38 for outputting the calculated stress Q and damage status to the external base station 60 via the communication antenna 39. The illustrated example shows the case of one channel input for processing the output power P of one piezoelectric device 20, but when incorporating a plurality of piezoelectric devices 20 in a column beam joint, can do. An example of the controller 30 is a computer having a storage means 31. The measurement means 32, the detection means 36, and the information communication means 38 are built into the computer program, and the stress Q of the structural members 2 and 3 is calculated from the output voltage V of the piezoelectric device 20. The relational expression R and the like necessary for calculation can be stored in the storage means 31.

  The damage detection system 10 in the illustrated example has a sensor 40 that is attached to the structural members 2 and 3 and measures displacement δ (for example, interlayer displacement) in addition to the piezoelectric device 20 and the controller 30. External power supply means 35 for supplying P to the sensor 40 is provided in the controller 30. In the external power supply means 35, the amount of power stored in the power storage means 33 and the amount of power required in the controller 30 (measurement means 32, detection means 36, information communication means 38, and other required power amounts of the controller 30 main body) Thus, the power may be supplied to the sensor 40 only when there is a sufficient amount of power in the power storage means 33. By driving the sensor 40 with electric power via the controller 30, the damage detection system 10 including the sensor 40 can be an energy-independent device. Further, the measured value (for example, displacement of the structural members 2 and 3) δ of the sensor 40 can be transmitted to the controller 30 or the external base station 50 via a wireless or wired information communication path 59.

  Any sensor 40 can be selected and used as long as the displacement δ of the structural members 2 and 3 can be measured from the measured values. For example, the sensor 40 is an acceleration sensor, and the measured value (acceleration) is integrated twice to obtain the displacement δ of the members 2 and 3. Alternatively, the sensor 40 may be a displacement sensor, and the displacement δ of the members 2 and 3 may be directly measured. By measuring the displacement δ of the structural members 2 and 3 using the sensor 40, the cumulative plastic strain energy Wp is calculated from the stress Q and the displacement δ of the structural members 2 and 3, as will be described later, and the damage is quantitatively evaluated. It becomes possible to do. However, since the damage to the structural members 2 and 3 can be detected to some extent from only the stress Q, the measurement of the displacement δ is not essential for the damage detection system. In the illustrated example, the controller 30 and the sensor 40 are connected by a wired power supply cable. For example, by using a system as disclosed in Patent Document 8, power is supplied from the controller 3 to the sensor 40 wirelessly. It is also possible. Further, in place of or in addition to the sensor 40, a monitoring sensor that collects data in various directions (for example, interlayer deformation angle) can be combined with the damage detection system 10 of the present invention.

  FIG. 2 shows a flow chart of the functions of the damage detection system 10 of FIG. The function of the damage detection system 10 of FIG. 1 will be described below with reference to the flowchart of FIG. First, when the electric power P is output from the piezoelectric device 20 in step S001, the output electric power P is input to the controller 30 in step S002, and is sent to and stored in the power storage means 33 via the measuring means 32 in step S020. That is, the damage detection system 10 causes the piezoelectric device 20 to output a large amount of electric power by directly applying substantially all of the force applied to the beam-column joint to the piezoelectric device 20 so that the controller 30 can be driven in a steady state or an emergency. It fulfills the power generation function to cover the necessary energy.

  FIG. 5 shows a power generation amount assumed when the damage detection system 10 is applied to a 25-story model structure with a height of 109 m. FIG. 5A shows the arrangement of the beam members 2 and the column members 3 on the specific floor of the model building 1, and the end portions of the beam members 2 are joined to the column members 3 with eight bolts. The amount of power generated in a steady state per bolt is assumed to be about 2 W in view of the horizontal force applied during disturbances such as relatively frequent wind loads. Since two, three, or four beam members 2 are attached to each column member 3, the power generation amount per column member on each floor is 32 W (= 2 units × 8 units × 2 W), 42 W (= 3 (8 units × 2 units) or 64 W (= 4 units × 8 units × 2 W) (see FIG. 5A).

  On the other hand, the power consumption required to maintain the functions of the controller 30 with 2-channel input and 1-channel output is usually 10 W or less, and the power required for radio such as the communication antenna 39 is about 10 mW. It is possible to sufficiently cover the power consumption required for the controller 30 and information communication by the power generation amount 32 to 64 W in each pillar member 1. FIG. 5B shows that the amount of power generation can be expected to be about 11.2 kW in an emergency such as an earthquake, and is necessary for the controller 30 and information communication even in an emergency where data processing and data communication can occur frequently. It can be confirmed that not only sufficient power consumption can be covered, but also power can be supplied to the external sensor 40 or the like (step S021).

  Steps S <b> 010 to S <b> 011 in FIG. 2 indicate that a vibration damping effect (damping structure) proportional to the energy conversion amount of the piezoelectric device 20 can be obtained by causing the piezoelectric device 20 to generate power. That is, in the damage detection system 10, while the piezoelectric device 20 absorbs and consumes seismic energy to generate power in step S010, the damage detection system 10 has a structure corresponding to the energy absorption amount Wh of the piezoelectric device 20 as described above with reference to the equation (1). Since the accumulated plastic strain energy Wp of the object 1 is reduced, a vibration damping function proportional to the power generation amount of the piezoelectric device 20 in step 020 is performed in step S011.

  In step S030 of FIG. 2, at the same time as the output power P of the piezoelectric device 20 is sent from the measuring means 32 to the power storage means 33 in step S020, the measured values (current value I, voltage value V) of the measuring means 32 are detected means. 36, the process of calculating the stress Q of the structural members 2 and 3 in the detection means 36 is shown. That is, in the damage detection system 10, substantially all of the force (load) applied to the structural members 2 and 3 of the structure 1 is directly applied to the piezoelectric device 20, so that the output voltage of the piezoelectric device 20 as shown in FIG. By obtaining a relational expression R between V and the stress Q of the structural members 2 and 3 in advance, the measurement means 32 can measure the stress Q of the structural members 2 and 3 in real time from the output voltage V of the piezoelectric device 20. it can. The relational expression R as in the illustrated example can be experimentally obtained in advance and stored in the storage means 31 of the controller 30, and the calculated stress Q of the members 2 and 3 is also accumulated and stored in the storage means 31. Can do.

Step S031 in FIG. 2 shows processing for detecting damage to the structural members 2 and 3 by the detection means 36 of the controller 30. In general, the damage to the structural members 2 and 3 can be grasped as the progress of plasticization (yield state) or the accumulated plastic strain energy Wp as described above with reference to the equation (1). For example, the relationship between load and interlayer deformation when a horizontal external force in one direction is input to the structural members 2 and 3 is shown in FIG. 7 using the yield strength Qy of the member and the corresponding yield deformation (elastic interlayer deformation) δy. It can be expressed as (A). In this case, the degree of progress of plasticization of the members 2 and 3 is defined as plastic deformation (δp−δy), and the plastic strain energy Wp accumulated in the members 2 and 3 can be expressed by the equation (2). Further, the relationship between load and interlayer deformation when a horizontal external force such as earthquake motion is input to the structural members 2 and 3 can be expressed as shown in FIG. 7B, and the plasticity of the members 2 and 3 in this case Is defined as cumulative plastic deformation δp in equation (3) obtained by adding the plastic deformations Δδp1, Δδp2, Δδp3, Δδp4 in each step of load-interlayer deformation, and the plastic strain energy Wp accumulated in the members 2 and 3 Can be expressed as in equation (4).
Wp = Qy · (δp−δy) …………………………………………………… (2)
δp = (Δδp1 + Δδp3) + (Δδp2 + Δδp4) (3)
Wp = Qy · δp ………………………………………………………………… (4)

  In step S031 in FIG. 2, since the stress Q of the structural members 2 and 3 is calculated but the displacement δ is not measured, the plastic deformation δp or the cumulative plastic strain energy Wp of the equations (3) to (4) is calculated. However, the degree of plasticization (yield state) of the members 2 and 3 can be detected based on the time history H of the stress Q as shown in FIG. That is, in the time history H of the stress Q in FIG. 4B, since the situation in which the stress Q maintains a constant value as shown by a one-dot chain line circle is a yield state, whether or not such a yield state occurs, The damage of the members 2 and 3 can be detected by obtaining the number of occurrences, the generation accumulated time, and the like. The stress Q and the damage status of the members 2 and 3 obtained by the detection means 32 are sent to the information communication means 38 in step S032, and can be output to the information communication means 52 of the external base station 60 via the communication antenna 39.

  In step S033 in FIG. 2, when the displacement δ of the structural members 2 and 3 is measured by the sensor 40 and the measured value δ is transmitted to the external base station 50 or the controller 30, the calculation means 53 of the external base station 50 is used. Alternatively, the displacement δ of the structural members 2 and 3 is obtained from the measured value of the sensor 40 by the calculation means 37 of the controller 30, and the time history of the stress Q and the displacement δ of the structural members 2 and 3 is obtained by the equations (3) to (4). The process which calculates the accumulated plastic strain energy Wp of the structural members 2 and 3 is shown. By calculating the cumulative plastic strain energy Wp, the damage of the members 2 and 3 can be quantitatively evaluated as the degree of plasticization. Also, for example, the accumulated plastic strain energy Wp (holding seismic performance, limit performance) possessed by the healthy members 2 and 3 before the earthquake disaster is obtained, and the accumulated plastic strain energy Wp (consumed seismic performance) is calculated after the earthquake disaster. Therefore, by comparing with the seismic performance possessed, it is possible to determine the soundness or margin after the earthquake (residual seismic performance = retained seismic performance-consumed seismic performance).

  As shown in the flowchart of FIG. 2, the damage detection system 10 of the present invention combines a piezoelectric device 20 that functions as an energy absorption type vibration damping mechanism with a controller 30, and applies a force applied to a column-beam joint of a structure 1 to the piezoelectric device. By directly acting on the system 20, a system that combines the three functions of a vibration suppression function (steps S010 to S011), a power generation function (steps S020 to 021), and a damage monitoring function (steps S030 to 033) with a single device. Can be realized. Moreover, since damage to the various structural members 2 and 3 of the structure 1 can be obtained independently of energy, it can be economically introduced into general structures, reducing both secondary damage and evacuees. The technology can be expected to spread.

  In this way, it is possible to provide the “method and system capable of accurately and economically detecting damage caused to a structural member in the event of an earthquake” that is an object of the present invention.

  FIG. 3A shows the structure 1 and the seismic isolation device in place of the piezoelectric device 20 of the damage detection system 10 between the structural members 2 and 3 (column beam joints) of the structure 1 as shown in FIG. 6 shows an embodiment sandwiched between the two. FIG. 3B shows that the piezoelectric devices 20 are installed between the laminated rubber and the upper foundation 7b, which are the main structural parts of the seismic isolation device 6, and between the laminated rubber and the lower foundation 7a, respectively. . As described above with reference to FIG. 1, the damage detection system 10 of the present invention incorporates a piezoelectric device in a portion that directly receives most of the energy input to the structure 1 during an earthquake, thereby It can detect damage and exerts great vibration control effect. In the case of FIG. 3 (A), damage detection targets the vertical support capability of the seismic isolation device 6, and power generation occurs due to fluctuations in the vertical force of the seismic isolation device 6 due to the overturning moment during the earthquake. This will reduce this overturning moment. As shown in FIG. 3, the piezoelectric device 20 is incorporated between the structure 1 to which seismic energy is applied and the seismic isolation device 6, and a large electric power is output from the piezoelectric device 20. The effect which combined 6 can be expected.

  FIG. 3C shows an embodiment in which the piezoelectric device 20 of the damage detection system 10 is sandwiched between the structural members 2 and 3 of the structure 1 and the brace material 4. FIG. 3D shows that the beam structure of the beam member 2 and the column member 3 has a pin structure, and all the seismic force is generated by the brace members 4 and 4 arranged on the inner side of the column beam structure via brackets 5a and 5b. It is shown that the piezoelectric device 20 is installed between both ends of the brace material 4 and the beam member 2 and the column member 3 to which the brackets 5a and 5b are attached. By applying substantially all of the force applied to the brace material 4 directly to the piezoelectric device 20, a large electric power is output from the piezoelectric device 20, and at the same time, the vibration damping effect of the piezoelectric device 20 and the earthquake resistance effect of the brace material 4 are combined. Can be expected. Further, by obtaining a relational expression R between the output voltage V of the piezoelectric device 20 and the stress Q of the brace material 4 in advance, the controller 30 measures the stress Q of the brace material 4 from the output voltage V of the piezoelectric device 20 in real time. Thus, damage to the brace material 4 can be detected.

DESCRIPTION OF SYMBOLS 1 ... Structure 1a ... Floor 1b ... Ceiling 2 ... Structural member (beam member) 2a ... Flange 3 ... Structural member (column member) 4 ... Brace reinforcement 5a, 5b ... Bracket 6 ... Seismic isolation device (laminated rubber)
7a ... Lower foundation 7b ... Upper foundation 8 ... Bolt 9 ... Nut 10 ... Damage detection system 20 ... Piezoelectric device 30 ... Controller 31 ... Storage means 32 ... Measuring means 33 ... Power storage means 34 ... Power supply means 35 ... External power supply means 36 ... Detection means 37 ... calculation means 38 ... information communication means 39 ... communication antenna 40 ... sensor 50 ... external base station 51 ... storage means 52 ... information communication means 53 ... calculation means 59 ... information communication path 60 ... damping device G ... ground P ... Output power H of piezoelectric device ... Time history R ... Relational expression Q ... Stress (load) δ ... Deformation (plastic deformation)
E ... Total energy input We at the time of earthquake ... Elastic vibration energy Wp ... Cumulative plastic strain energy Wh ... Amount of energy absorbed by damping

Claims (8)

The piezoelectric device is sandwiched between structural members to be bonded to each other so that the direction of the force applied to the bonded portion of the structural member coincides with the pressing direction in which power proportional to the pressure of the piezoelectric device is output. , The output power of the piezoelectric device is input to a controller provided with power storage means and stored, and the controller driven by the stored power calculates the stress of the structural member from the output voltage of the piezoelectric device, A damage detection method for a structure obtained by detecting damage to the structural member based on a time history. 2. The method of claim 1, wherein the controller driven by the stored electric power outputs the calculated stress value of the structural member to an external base station. 3. The method according to claim 2, wherein a sensor driven by electric power via the controller is attached to the structural member and a measurement value of the sensor is output to the external base station or controller. A damage detection method for a structure comprising calculating a cumulative plastic strain energy of the structural member from a stress history of the sensor and a time history of the measurement value of the sensor, and detecting damage of the structural member based on the cumulative plastic strain energy. 4. The method according to claim 1, wherein the piezoelectric device is replaced or added between the structural members of the structure, between the structural member of the structure and the brace material, or with the structure. Damage detection method for structures sandwiched between seismic isolation devices. A piezoelectric device sandwiched between structural members to be bonded to each other so that a direction of a force applied to a bonded portion of the structural member and a pressurizing direction in which power proportional to the pressure is output coincide with each other; Power storage means for inputting and storing output power of the device and driving by the power storage means to calculate the stress of the structural member from the output voltage of the piezoelectric device and detect damage to the structural member based on the time history of the stress A damage detection system for a structure comprising a controller having detection means. 6. The damage detection system for a structure according to claim 5, wherein the controller is provided with information communication means that is driven by the power storage means and outputs a stress calculation value of the structural member to an external base station. 7. The system according to claim 6, wherein a sensor is provided that is attached to the structural member and is driven by electric power via the controller to output a measurement value to the external base station or controller, and the stress of the structural member is provided to the external base station or controller. And a damage detection system for a structure comprising a calculation means for calculating a cumulative plastic strain energy of the structural member from a time history of the measurement value of the sensor, and detecting damage to the structural member based on the cumulative plastic strain energy. 8. The system according to claim 5, wherein the piezoelectric device is replaced or added between the structural members of the structure, between the structural members of the structure and the brace material, or with the structure. Damage detection system for structures sandwiched between seismic isolation devices.