Method for creating simulated seismic waveforms, program, seismic testing machine, simulated seismic waveform creation system, and simulated vibration creation system.

Abstract

This invention provides a method for creating simulated seismic waveforms that can be used in a two-axis seismic testing machine and that can reflect horizontal displacements similar to those of actual earthquakes. [Solution] The simulated earthquake waveform creation method uses a provisional vibration axis angle θ1, coordinate data X, and coordinate data Y based on first data represented on a Cartesian coordinate system to calculate projected coordinate data X' and projected coordinate data Y'. Using the projected coordinate data X' and projected coordinate data Y', the distance L from the origin at each point in time along the time series is calculated. When the provisional vibration axis angle θ1 is varied, the provisional vibration axis angle θ1 that maximizes the sum of distances L is defined as the vibration axis angle θ'. A straight line that intersects the x-axis at an angle of vibration axis angle θ' on the Cartesian coordinate system is defined as the vibration axis. Second data is prepared, representing the points indicated by each distance L corresponding to each point in time along the time series on the vibration axis, and the system vibrates horizontally according to the second data in order of each point in time along the time series.

Description

Technical Field

[0001] The present disclosure relates to a simulated seismic waveform creation method, a program, a seismic testing machine, a simulated seismic waveform creation system, and a simulated vibration creation system that are used for two-axis seismic testing machines.

Background Art

[0002] Conventionally, two-axis seismic testing machines for reproducing the influence of multi-axis vibration caused by earthquakes are known. A two-axis seismic testing machine can perform seismic tests by vibrating in two axial directions, namely the horizontal direction and the vertical direction. It is common that the horizontal direction in which a two-axis seismic testing machine vibrates is displaced in only one direction.

[0003] For example, Patent Document 1 discloses a vibration testing apparatus. The vibration testing apparatus includes a displacement applying unit that relatively displaces a loading table on which a test specimen is placed in the horizontal direction with respect to a vibration table, and an operation interlocking unit that interlocks the operation of the displacement applying unit and the operation of the vibration applying unit.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] For example, in an actual earthquake, as horizontal vibration, displacement occurs over time while vibrating mainly in a fixed direction and including components other than the fixed direction. However, in the conventional two-axis seismic testing machines, it is common to perform displacement only in one direction, north-south or east-west, when conducting a seismic test. For this reason, the conventional two-axis seismic testing machines are insufficient for performing tests that reflect actual seismic motion, and there is room for improvement.

[0006] Therefore, the purpose of this disclosure is to provide a method for creating simulated seismic waveforms that can be used in a two-axis seismic testing machine and that reflect horizontal displacements such as those of actual earthquakes. [Means for solving the problem]

[0007] A simulated seismic waveform creation method according to one aspect of the present disclosure is a method for creating a simulated seismic waveform that reproduces the horizontal vibration behavior based on coordinate data of an earthquake at a single point, wherein the coordinate data consists of horizontal coordinate data X and vertical coordinate data Y at each point in time along a time series with respect to the origin before the start of vibration, and first data is prepared by representing the coordinate data X and coordinate data Y at each point in time along the time series with respect to the origin on an orthogonal coordinate system consisting of the x axis and the y axis, and using the provisional vibration axis angle θ1 based on the first data, the coordinate data X, and the coordinate data Y, projected coordinate data X' and projected coordinate data Y' are calculated using equations (1) and (2). X'=(x*cosθ1+y*sinθ1)*cosθ1 Formula (1) Y'=(x*cosθ1+y*sinθ1)*sinθ1 Formula (2) Using the projected coordinate data X' and the projected coordinate data Y', the distance L from the origin for each point in time along the time series is calculated using equation (3). L=√(x' 2 +y' 2 ) Formula (3) Using the aforementioned provisional vibration axis angle θ1 as a reference, the provisional vibration axis angle θ1 is varied based on equations (1) and (2), and the provisional vibration axis angle θ1 that maximizes the sum of the distances L is defined as the vibration axis angle θ'. A straight line that intersects the x-axis at an angle of the vibration axis angle θ' on the Cartesian coordinate system is defined as the vibration axis, and second data is prepared, representing the points indicated by each distance L corresponding to each of the aforementioned time points along the time series, on the vibration axis, and the system is vibrated horizontally according to the second data in order of each of the aforementioned time points along the time series. [Effects of the Invention]

[0008] According to one aspect of this disclosure, the method for creating simulated earthquake waveforms can be used in a two-axis earthquake testing machine and can reflect horizontal displacements similar to those of actual earthquakes. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 shows the shaking at specific locations during the Great Hanshin Earthquake in southern Hyogo Prefecture. [Figure 2] Figure 2 shows the horizontal acceleration data for shaking in Kobe Port during the Great Hanshin Earthquake. [Figure 3] Figure 3 is an external view of the seismic testing machine with the structure fixed in place. [Figure 4] Figure 4 is a block diagram of the simulated vibration generation system. [Figure 5] Figure 5 shows the relationship between time, coordinate data X (east-west direction), coordinate data Y (north-south direction), angle, and corrected angle. [Figure 6] Figure 6 shows the first data set, represented on a Cartesian coordinate system consisting of the x and y axes, based on Figure 5. [Figure 7] Figure 7 shows the distance L from the origin to each point after projection. [Figure 8] Figure 8 shows the second data set, represented on a Cartesian coordinate system consisting of the x and y axes, based on Figure 7. [Figure 9] Figure 9 shows the shaking that would occur in the event of an earthquake off the Pacific coast of the Tohoku region. [Figure 10] Figure 10 is a flowchart showing an example of the operation of the simulated earthquake waveform generation system according to the embodiment. [Modes for carrying out the invention]

[0010] The embodiments will be described in detail below with reference to the drawings.

[0011] It should be noted that all of the embodiments described below are comprehensive or specific examples. The numerical values, shapes, materials, constituent elements, arrangement positions of constituent elements, connection modes, and the like shown in the following embodiments are mere examples, and are not intended to limit the present disclosure. Further, among the constituent elements in the following embodiments, constituent elements not recited in the independent claims are described as optional constituent elements.

[0012] Each drawing is a schematic view and is not necessarily strictly illustrated. Further, in each drawing, the same constituent members are denoted by the same reference numerals.

[0013] Further, expressions such as the north-south direction are used in the following embodiments. For example, the north-south direction not only means a perfect north-south direction, but also means a substantially north-south direction, that is, including an error of about several percent. In addition, the north-south direction means the north-south direction within a range where the effects of the present disclosure can be achieved. The same applies to other expressions using "directions".

[0014] (Findings leading to the present disclosure) First, the findings leading to the present disclosure will be described with reference to FIG. 1 and FIG. 2.

[0015] FIG. 1 is a diagram showing shaking at a specific point during the Southern Hyogo Prefecture Earthquake. In FIG. 1, the vertical axis represents displacement (mm), and the horizontal axis represents time (seconds). The graph indicated by dot hatching shows shaking in the north-south direction, the graph indicated by the solid line shows shaking in the east-west direction, and the graph indicated by oblique hatching shows shaking in the vertical direction. For example, A1 indicated by the broken line in FIG. 1 indicates that the object moved about 150 mm north from the initial position. Further, A2 indicated by the broken line in FIG. 1 indicates that the object moved about 180 mm south from the initial position.

[0016] As shown in Figure 1, earthquake shaking can be represented by decomposing it into three directions: the north-south and east-west directions included in the horizontal direction, and the vertical direction. The simulated earthquake waveform generation method of this disclosure uses the north-south and east-west directions included in the horizontal direction of these three directions. The simulated earthquake waveform generation method of this disclosure is realized by converting the time-dependent displacement amounts in the north-south and east-west directions into a specific direction and representing them.

[0017] Figure 2 shows the horizontal acceleration data for shaking in Kobe Port during the Great Hanshin Earthquake. According to Figure 2, it has been confirmed that the shaking during this earthquake occurred in a specific direction within a certain range.

[0018] In Figure 1, horizontal displacements are mixed in the north-south and east-west directions, but the direction of the shaking is roughly fixed in one direction. Therefore, we have gained the insight that even a two-axis seismic testing machine may be able to reproduce shaking in one direction, including the amount of displacement in the north-south and east-west directions.

[0019] Thus, since the shaking occurs in one direction relative to the horizontal, it can be considered that in actual earthquakes, the direction of shaking is generally fixed in one direction.

[0020] Therefore, the configuration and functions of the simulated earthquake waveform creation method, program, earthquake testing machine, simulated earthquake waveform creation system, and simulated vibration creation system according to this embodiment will be described below.

[0021] (Embodiment) <Configuration and Function> The configuration and functions of the earthquake testing machine 10, the simulated earthquake waveform generation system 1a, and the simulated earthquake vibration generation system 1 will be described below with reference to Figures 3 to 9.

[0022] Figure 3 is an external view of the earthquake testing machine 10 with the structure fixed. Figure 4 is a block diagram of the simulated vibration creation system 1. Figure 5 is a diagram showing the relationship between time, coordinate data X (east-west direction), coordinate data Y (north-south direction), angle, and corrected angle. In Figure 5, the acceleration data from Figure 2 is transformed to show the coordinate data X (east-west direction), coordinate data Y (north-south direction), angle, and corrected angle for each time point. Figure 6 is a diagram showing the first data represented on a Cartesian coordinate system consisting of the x and y axes based on Figure 5. Figure 7 is a diagram showing the distance L from the origin to each point after projection. Figure 8 is a diagram showing the second data represented on a Cartesian coordinate system consisting of the x and y axes based on Figure 7. Figure 9 is a diagram showing the shaking in the case of the Tohoku-Pacific Ocean Earthquake.

[0023] As shown in Figures 3 and 4, the seismic testing machine 10 is a biaxial seismic testing machine that reproduces horizontal vibration behavior based on earthquake coordinate data at a specific point to test the seismic resistance of a structure.

[0024] The earthquake testing machine 10 is equipped with a vibration exciter 21 and a vibration control device 22.

[0025] The vibration exciter 21 is a device that, under the control of the vibration control device 22, applies a force to vibrate the vibration table 20, which will be described later. For example, the vibration exciter 21 is a two-axis device capable of exciting the vibration table 20 in both the horizontal and vertical directions. For example, the vibration exciter 21 can excite in two axes: one axis in the north-south or east-west direction and one axis in the vertical direction. The vibration exciter 21 is realized by a vibration mechanism such as a hydraulic cylinder and a pressure accumulator.

[0026] The vibration control device 22 can vibrate the vibration table 20 by controlling the exciter 21 according to the second data, which will be described later.

[0027] The earthquake testing machine 10 may be mounted on the simulated vibration creation system 1. Alternatively, the earthquake testing machine 10 may be integrated with the simulated vibration creation system 1, or they may be separate and independent, and only connected in a communication manner. The simulated vibration creation system 1 further comprises a simulated earthquake waveform creation system 1a.

[0028] The simulated earthquake waveform creation system 1a is a control computer having an acquisition unit 11 and a processing unit 12. The simulated earthquake waveform creation system 1a is a system that creates earthquake waveforms for simulating earthquake motion. In addition to the earthquake testing machine 10, acquisition unit 11 and processing unit 12, the simulated earthquake waveform creation system 1a may also include a shaking table 20.

[0029] The vibration table 20 is a table of a predetermined shape on which a test specimen can be placed. In Figure 3, a lighting device is installed on the vibration table 20 as an example of a test specimen. The test specimen is not limited to a lighting device, but may also be a building, furniture, etc., and is not limited to this embodiment.

[0030] The acquisition unit 11 is configured to acquire coordinate data of an earthquake at a single location. The coordinate data of an earthquake at a single location may be, for example, data calculated based on acceleration data shown in Figure 2 (by integrating the acceleration data twice). Furthermore, the coordinate data or acceleration data may be obtained from a database such as that of the Japan Meteorological Agency, or from an external device such as a seismometer.

[0031] The processing unit 12 may prepare first data as shown in Figure 6 based on the coordinate data as shown in Figure 5 acquired by the acquisition unit 11. This coordinate data can be represented in Cartesian coordinates. In other words, this coordinate data consists of horizontal coordinate data X (east-west direction) and vertical coordinate data Y (north-south direction) for each point in time along the time series, with respect to the origin (P1 in Figure 6) before the start of vibration. The coordinate data X and coordinate data Y indicate a location.

[0032] In this case, the first data set is data that represents the coordinate data X and coordinate data Y at each point in time along the time series relative to the origin, based on Figure 5, on a Cartesian coordinate system consisting of the x and y axes. Specifically, in the first data set, the coordinate data X (east-west direction) from Figure 5 is plotted on a Cartesian coordinate system with the x-axis (horizontal axis of Figure 6) representing the displacement in the east-west direction, and the coordinate data Y (north-south direction) from Figure 5 is plotted on a Cartesian coordinate system with the y-axis (vertical axis of Figure 6) representing the displacement in the north-south direction.

[0033] For example, in Figure 5, with the point before the start of vibration as the origin, at point P1, the time is "0.00", coordinate data X is "0.0", and coordinate data Y is "0.0".

[0034] Furthermore, at point P2, the time is "0.02", coordinate data X is "-2.0", coordinate data Y is "5.0", angle is "112°", and corrected angle is "112°".

[0035] Furthermore, at location P3, the time is "0.06", coordinate data X is "-3.0", coordinate data Y is "11.0", angle is "105°", and corrected angle is "105°".

[0036] Furthermore, at location P4, the time is "0.08", coordinate data X is "-10.0", coordinate data Y is "10.0", angle is "135°", and corrected angle is "135°".

[0037] Furthermore, at location P5, the time is "0.10", coordinate data X is "0.0", coordinate data Y is "-4.0", angle is "-90°", and corrected angle is "90°".

[0038] Furthermore, at point P6, the time is "0.12", coordinate data X is "5.0", coordinate data Y is "-5.0", angle is "-45°", and corrected angle is "135°".

[0039] Furthermore, at point P7, the time is "0.14", coordinate data X is "10.0", coordinate data Y is "-10.0", angle is "-45°", and corrected angle is "135°".

[0040] Furthermore, at location P8, the time is "0.16", coordinate data X is "5.0", coordinate data Y is "-12.0", angle is "-67°", and corrected angle is "113°".

[0041] The processing unit 12 can obtain the first data shown in Figure 6 by plotting points P1 to P8 in Figure 5 on a Cartesian coordinate system consisting of the x and y axes.

[0042] As shown in Figures 5 and 6, the processing unit 12 uses an inverse tangent function to calculate the angle of each point indicated by each time point along the time series for each point P1 to P8 (each plot) indicated by the coordinate data X and coordinate data Y indicated by each point along the time series in the first data. The angle of each point is the angle between the positive direction of the x-axis passing through the origin and the line connecting the origin to each point, and is the angle measured counterclockwise from the positive direction of the x-axis.

[0043] Next, the processing unit 12 retains the angles at each point calculated in chronological order if they are positive numbers, and adds 180° to them if they are negative numbers.

[0044] Next, the processing unit 12 calculates the provisional vibration axis angle θ1 from each corrected angle calculated in chronological order. In this way, the processing unit 12 calculates the provisional vibration axis angle θ1 based on the earthquake data.

[0045] For example, the processing unit 12 may calculate the provisional vibration axis angle θ1 by calculating the corrected average angle θ1 based on the seismic data. The corrected average angle θ1 will be 118°. In this case, the average angle θ1 represents the provisional vibration axis angle θ1.

[0046] Next, the processing unit 12 uses the provisional vibration axis angle θ1, coordinate data X, and coordinate data Y based on the first data to calculate the projected coordinate data X' and projected coordinate data Y' using the following equations (1) and (2).

[0047] X'=(x*cosθ1+y*sinθ1)*cosθ1 Formula (1) Y'=(x*cosθ1+y*sinθ1)*sinθ1 Formula (2) For example, the processing unit 12 calculates the projected points P1' to P8', which correspond to each point P1 to P8 indicated by the coordinate data X' and coordinate data Y'. The projected coordinate data X' and projected coordinate data Y' indicate the projected locations.

[0048] Next, the processing unit 12 calculates the distance L from the origin to each point after projection, which is shown at each point in time along the time series, using the following equation (3).

[0049] L=√(x' 2 +y' 2 ) Formula (3)

[0050] For example, as shown in Figure 7, the processing unit 12 calculates the distance L from the origin to each point P1' to P8' after projection.

[0051] For example, in Figure 7, at point P1', which is the origin, the time is "0.00" and the distance L is "0.0".

[0052] Furthermore, at point P2', the time is "0.02" and the distance L is "5.30".

[0053] Furthermore, at point P3', the time is "0.06" and the distance L is "10.92".

[0054] Furthermore, at point P4', the time is "0.08" and the distance L is "13.78".

[0055] Furthermore, at point P5', the time is "0.10" and the distance L is "3.39".

[0056] Furthermore, at point P6', the time is "0.12" and the distance L is "6.89".

[0057] Furthermore, at point P7', the time is "0.14" and the distance L is "13.78".

[0058] Furthermore, at point P8', the time is "0.16" and the distance L is "12.83".

[0059] Note that the ± values ​​for each point P1' to P8' shown in Figure 8 are determined based on the pre-projection plot shown in Figure 6.

[0060] Of these, the distance L is maximum at time 0.08, and the distance L at this time is 13.78 mm. In other words, the maximum displacement amount obtained by this disclosure is smaller than the maximum displacement amount in only one direction (maximum displacement amount in the north-south direction only in Figure 5), which is 12 mm, based on time 0.16 (point P8) in Figure 5, and the actual maximum displacement amount of the earthquake, which was 14.14 mm. In other words, the error has been reduced from 15% to 2.5%.

[0061] Next, we will explain the procedure for obtaining simulated seismic waveforms, which will be used as input information for the earthquake testing machine 10.

[0062] The processing unit 12 uses the obtained provisional vibration axis angle θ1 as a reference and varies the value of the provisional vibration axis angle θ1 based on equations (1) and (2).

[0063] Specifically, the processing unit 12 calculates the vibration axis angle θ' that maximizes the sum of the calculated distances L by varying the value of the provisional vibration axis angle θ1 based on equations (1) and (2). For example, the processing unit 12 uses spreadsheet software or the like to calculate the sum of distances L within a range of approximately ±10° from the provisional vibration axis angle θ1, and sets the point where the distance L is maximized as the vibration axis angle θ'. In this way, when the calculation is performed in the case of Figure 7, the vibration axis angle θ' becomes 122°.

[0064] As shown in Figure 8, the vibration axis is defined as the straight line shown by the dashed line that intersects the x-axis at an angle θ' with respect to the x-axis in the Cartesian coordinate system. In this case, the processing unit 12 can obtain the second data shown in Figure 8 by plotting the points indicated by each distance L corresponding to each time point in Figure 7 on the vibration axis in the Cartesian coordinate system. The points indicated by distance L are the points at the tip of the vibration axis, which are a distance L away from the origin. In other words, as shown in Figure 8, the processing unit 12 can generate the second data (simulated seismic waveform data) from each point P1' to P8' based on the vibration axis angle θ' and the points indicated by each distance L.

[0065] This allows the earthquake testing machine 10 to vibrate horizontally according to the second data in chronological order at each point in time.

[0066] Furthermore, according to this embodiment, the second data can be used.

[0067] For example, the simulated earthquake waveform generation method of this disclosure may be a program for execution by a computer, and such program may be installed on the earthquake testing machine 10 or incorporated into spreadsheet software such as Excel.

[0068] In the simulated seismic waveform generation method of this disclosure using the said program, the second data is output to the biaxial seismic testing machine, and the method can be implemented on the biaxial seismic testing machine.

[0069] For example, as shown in Figure 9, in the case of the Tohoku-Pacific Ocean Earthquake, there is a difference in the waveform of the shaking between the first and second halves of the earthquake. In this case, it can be seen that the direction of the shaking changes over time.

[0070] The above-described simulated earthquake waveform illustrates the case where relative displacement occurs with respect to a single vibration axis, but this embodiment is not limited to this. For example, as shown in Figure 9, when the direction of shaking changes over time, this embodiment can also set up two or more vibration axes and perform relative displacement. Specifically, as shown in Figures 9(a) to (c), two sets of coordinate data with different earthquake shaking may be prepared. The processing unit 12 may determine the vibration axis, displacement amount, distance L, etc., corresponding to each coordinate data using the method described above. Subsequently, the vibration axes and displacement amounts obtained in Figures 9(d) to (f) may be used as continuous data.

[0071] <Example of operation> Next, with reference to Figure 10, we will describe the operation examples of the simulated earthquake waveform creation method, program, earthquake testing machine 10, simulated earthquake waveform creation system 1a, and simulated vibration creation system 1 in this embodiment.

[0072] Figure 10 is a flowchart showing an example of the operation of the simulated earthquake waveform generation system 1a according to the embodiment.

[0073] First, the acquisition unit 11 acquires the coordinate data of an earthquake at a single location (S11).

[0074] Next, the processing unit 12 prepares the first data based on the coordinate data (S12).

[0075] Next, the processing unit 12 calculates the angle at each point in time based on the first data. If the angle is a positive number, it is retained as is without modification. If the angle is a negative number, it calculates a corrected angle by adding 180° (S13).

[0076] Next, the processing unit 12 calculates the provisional vibration axis angle θ1 by calculating the average angle θ1 from each corrected angle (S14).

[0077] Next, the processing unit 12 uses the provisional vibration axis angle θ1, coordinate data X, and coordinate data Y based on the first data to calculate the projected coordinate data X' and projected coordinate data Y' using equations (1) and (2) (S15).

[0078] Next, the processing unit 12 uses equation (3) to calculate the distance L from the origin to each point after projection, which is shown at each point in time along the time series (S16).

[0079] Next, the processing unit 12 calculates the vibration axis angle θ' that maximizes the sum of the distances L calculated in step S16 by varying the value of the provisional vibration axis angle θ1 based on equations (1) and (2) (S17).

[0080] Next, the processing unit 12 generates second data (simulated seismic waveform data) based on the vibration axis angle θ' and the points indicated by each distance L (S18). As a result, the simulated seismic waveform creation system 1a can excite the shaking table 20 based on the second data.

[0081] Then, the flowchart in Figure 10 is finished.

[0082] <Effects and Effects> Next, the operation and effects of the simulated seismic waveform creation method, program, seismic testing machine 10, simulated seismic waveform creation system 1a, and simulated vibration creation system 1 in this embodiment will be described.

[0083] The simulated seismic waveform creation method of Technology 1 in this embodiment is a method for creating a simulated seismic waveform that reproduces the horizontal vibration behavior based on the coordinate data of an earthquake at a single point, wherein the coordinate data consists of horizontal coordinate data X and vertical coordinate data Y at each point in time along the time series with respect to the origin before the start of vibration, and first data is prepared by representing the coordinate data X and coordinate data Y at each point in time along the time series with respect to the origin on a Cartesian coordinate system consisting of the x axis and the y axis, and using the provisional vibration axis angle θ1, coordinate data X, and coordinate data Y based on the first data, the projected coordinate data X' and projected coordinate data Y' are calculated using equations (1) and (2). X'=(x*cosθ1+y*sinθ1)*cosθ1 Formula (1) Y'=(x*cosθ1+y*sinθ1)*sinθ1 Formula (2) Using the projected coordinate data X' and Y', the distance L from the origin at each point in time along the time series is calculated using equation (3). L=√(x' 2 +y' 2 ) expression (3) Using the provisional vibration axis angle θ1 as a reference, the provisional vibration axis angle θ' is defined as the provisional vibration axis angle θ1 at which the sum of distances L is maximized when the provisional vibration axis angle θ1 is varied according to equations (1) and (2). In the Cartesian coordinate system, the vibration axis is defined as the straight line that intersects the x-axis at an angle of vibration axis angle θ'. Second data is prepared, representing the points indicated by each distance L corresponding to each time point in the time series, and the system is vibrated horizontally according to the second data in the order of each time point in the time series.

[0084] According to this method, it is possible to generate a second set of data in which the coordinate data of an earthquake at a single point is represented on the vibration axis.

[0085] Therefore, this method for creating simulated seismic waveforms allows the use of a biaxial seismic testing machine based on the second data set, and also allows for the reflection of horizontal displacements similar to those of actual earthquakes.

[0086] In the simulated seismic waveform creation method of technique 2 in this embodiment, the first data is used to calculate the provisional vibration axis angle θ1 based on the angle at each point in time along the time series, using an inverse tangent function on the coordinate data X and the coordinate data Y.

[0087] According to this, a two-axis seismic testing machine can be used based on the second set of data, and it can better reflect horizontal displacements, such as those in actual earthquakes.

[0088] The program of Technology 3 in this embodiment is a program for a computer to execute a method for creating simulated earthquake waveforms.

[0089] This program also produces the same effects as described above.

[0090] The earthquake testing machine 10 of Technology 4 in this embodiment includes an exciter 21 that excites a shaking table 20 for placing a test specimen, and a vibration control device 22 that controls the exciter 21. The vibration control device 22 controls the exciter 21 using second data prepared by the simulated earthquake waveform creation method.

[0091] This earthquake testing machine 10 also exhibits the same effects as described above.

[0092] The simulated earthquake waveform creation system 1a of technology 5 in this embodiment is a simulated earthquake waveform creation system 1a that reproduces horizontal vibration behavior based on coordinate data of an earthquake at a single point, and comprises an acquisition unit 11 and a processing unit 12 that acquire coordinate data consisting of horizontal coordinate data X and vertical coordinate data Y at each point in time along the time series with respect to the origin before the start of vibration, and the processing unit 12 prepares first data in which the coordinate data X and coordinate data Y at each point in time along the time series with respect to the origin are represented on an orthogonal coordinate system consisting of the x axis and the y axis, and using the provisional vibration axis angle θ1, coordinate data X, and coordinate data Y based on the first data, calculates projected coordinate data X' and projected coordinate data Y' using equations (1) and (2), X'=(x*cosθ1+y*sinθ1)*cosθ1 Formula (1) Y'=(x*cosθ1+y*sinθ1)*sinθ1 Formula (2) Using the projected coordinate data X' and Y', the distance L from the origin at each point in time along the time series is calculated using equation (3). L=√(x' 2 +y' 2 ) expression (3) Using the provisional vibration axis angle θ1 as a reference, the provisional vibration axis angle θ' is defined as the provisional vibration axis angle θ1 at which the sum of distances L is maximized when the provisional vibration axis angle θ1 is varied according to equations (1) and (2). In the Cartesian coordinate system, the vibration axis is defined as the straight line that intersects the x-axis at an angle of vibration axis angle θ'. Second data is prepared, representing the points indicated by each distance L corresponding to each time point in the time series, and the system is vibrated horizontally according to the second data in the order of each time point in the time series.

[0093] This simulated earthquake waveform generation system 1a also produces the same effects as described above.

[0094] The simulated vibration creation system 1 of Technology 6 in this embodiment further comprises a simulated earthquake waveform creation system 1a, an exciter 21 for exciting a vibration table 20 for placing a test specimen, and a vibration control device 22 for controlling the exciter 21, which further comprises an earthquake testing machine 10.

[0095] This simulated vibration generation system 1 also produces the same effects as described above.

[0096] (Other variations, etc.) Although the present disclosure has been described above based on embodiments, the present disclosure is not limited to the embodiments described above.

[0097] Furthermore, this disclosure also includes forms obtained by applying various modifications to the embodiments that a person skilled in the art could conceive, and forms realized by arbitrarily combining the components and functions of the embodiments without departing from the spirit of this disclosure. [Industrial applicability]

[0098] The seismic testing equipment and other devices described herein are useful for vibration testing of structures such as buildings and installations. [Explanation of Symbols]

[0099] 1. Simulated Vibration Creation System 1a System for generating simulated earthquake waveforms 10. Earthquake testing machine 11 Acquisition Department 12 Processing Units 20 Vibration Table 21 Vibration exciter 22 Vibration control device

Claims

1. A method for creating simulated earthquake waveforms that reproduces horizontal vibration behavior based on earthquake coordinate data at a single point, The aforementioned coordinate data consists of horizontal coordinate data X and vertical coordinate data Y at each point in time along a time series, relative to the origin before the start of vibration. With respect to the aforementioned origin, a first data set is prepared in which the coordinate data X and the coordinate data Y at each of the aforementioned time points along the time series are represented on an orthogonal coordinate system consisting of the x-axis and the y-axis. The provisional vibration axis angle θ based on the first data mentioned above. １ Using the coordinate data X and the coordinate data Y, the projected coordinate data X' and the projected coordinate data Y' are calculated using equations (1) and (2). X'=(x*cosθ １ +y*sinθ １ )*cosθ １ Equation (1) Y'=(x*cosθ １ +y*sinθ １ )*sinθ １ Equation (2) Using the projected coordinate data X' and the projected coordinate data Y', the distance L from the origin for each point in time along the time series is calculated using equation (3). L = √(x') ２ +y' ２ Equation (3) The aforementioned temporary vibration axis angle θ １ Based on this, the provisional vibration axis angle θ is determined based on equations (1) and (2). １ When the value is varied, the provisional vibration axis angle θ that maximizes the sum of the distances L is the value of the provisional vibration axis angle θ. １ Let θ' be the vibration axis angle. In the aforementioned orthogonal coordinate system, a straight line intersecting the x-axis at an angle θ' is defined as the vibration axis, and a second data set is prepared in which the points indicated by each distance L corresponding to each time point along the time series are represented on the vibration axis. The second data is vibrated horizontally according to each of the aforementioned time points in the aforementioned time series. Method for creating simulated earthquake waveforms.

2. In the first data, the arctangent function is used with respect to the coordinate data X and the coordinate data Y to determine the provisional vibration axis angle θ based on the angle at each of the time points along the time series. １ Calculate A method for creating simulated earthquake waveforms according to claim 1.

3. A computer for executing the simulated earthquake waveform generation method according to claim 1 or 2. program.

4. A vibration exciter that vibrates the vibration table for which the test specimen is placed, The system includes a vibration control device for controlling the aforementioned vibration exciter, The vibration control device controls the vibration exciter using the second data prepared by the simulated seismic waveform creation method described in claim 1 or 2. Earthquake testing machine.

5. A simulated earthquake waveform generation system that reproduces horizontal vibration behavior based on earthquake coordinate data at a single point, An acquisition unit acquires coordinate data consisting of horizontal coordinate data X and vertical coordinate data Y at each point in time along a time series, relative to the origin before the start of vibration. Equipped with a processing unit, The aforementioned processing unit, With respect to the aforementioned origin, a first data set is prepared in which the coordinate data X and the coordinate data Y at each of the aforementioned time points along the time series are represented on an orthogonal coordinate system consisting of the x-axis and the y-axis. The provisional vibration axis angle θ based on the first data mentioned above. １ Using the coordinate data X and the coordinate data Y, the projected coordinate data X' and the projected coordinate data Y' are calculated using equations (1) and (2). X'=(x*cosθ １ +y*sinθ １ )*cosθ １ Equation (1) Y'=(x*cosθ １ +y*sinθ １ )*sinθ １ Equation (2) Using the projected coordinate data X' and the projected coordinate data Y', the distance L from the origin for each point in time along the time series is calculated using equation (3). L = √(x') ２ +y' ２ Equation (3) The aforementioned temporary vibration axis angle θ １ Based on this, the provisional vibration axis angle θ is determined based on equations (1) and (2). １ When the value is varied, the provisional vibration axis angle θ that maximizes the sum of the distances L is the value of the provisional vibration axis angle θ. １ Let θ' be the vibration axis angle. In the aforementioned orthogonal coordinate system, a straight line intersecting the x-axis at an angle θ' is defined as the vibration axis, and a second data set is prepared in which the points indicated by each distance L corresponding to each time point along the time series are represented on the vibration axis. The second data is vibrated horizontally according to each of the aforementioned time points in the aforementioned time series. A system for generating simulated earthquake waveforms.

6. A simulated earthquake waveform generation system according to claim 5, The seismic testing machine comprises a vibration exciter that vibrates a shaking table for placing a test specimen, and a vibration control device that controls the vibration exciter. A system for creating simulated vibrations.

Images