Testing Results

The objective of the component tests is to determine the hysteresis loop characterizing the inelastic behavior of the damper. The displacement and force are obtained from the built-in LVDT and the loadcell of the actuator, respectively.

The experimental hysteresis of the full-scale damper is plotted in Fig. 4.22 which shows a stable behavior of the damper. Curve fitting was performed on this hysteresis to determine the elastic stiffness of the damper for the hysteresis (Fig. 4.23). It is observed that the boundary conditions of the damper are not completely fixed. A reduction factor

φ

(Table 4.8) can be taken to modifies the stiffness calculated according to Eq. (2.13). If the upper and lower boundaries are considered as completely fixed,

φ

takes 1. In the component test of the full-scale damper,

φ

takes 0.75. The comparison between experimental and theoretical stiffness is summarized in Table 4.9.

Table 4.8 The reduction factor and stiffness of the full-scale damper

φ 0.75

k

d

φ ′ 2242 t m

Table 4.9 Comparison between the experimental and theoretical stiffness for the full-scale damper

Experimental: k

₁

2097 t m Theoretical: φ ′ k

_d

2242 t m Difference: k

¹

k

^d

k φ φ

− ′

′ 6 %

-40 -30 -20 -10 0 10 20 30 40 Deformation (mm)

-50 -25 0 25 50

Force (Ton)

USD Prototype Test 2004-0115

Fig. 4.22 Experimental hysteresis loop of the full-scale damper

−0.05 −0.025 0 0.025 0.05

−30

−20

−10 0 10 20 30

Displacement (m)

Force (t)

k1=2097 t/m k

2=409 t/m

D vs F Fit 1 Fit 2

Fig. 4.23 Curve fitting for determining the experimental stiffness of the full-scale damper

Seismic Performance Tests 5

In order to assess the effectiveness and feasibility of the damper through the earthquake, a series of shaking table test simulating the real earthquake scenario have been conducted in the Structural Dynamic Laboratory. In section 5.1, the experimental setup including the 5-story steel model structure, seismic shaking table and instrumentations are introduced concisely. The design of the metallic yielding damper for this structure is summarized. The assessment of seismic performance of the damper follows. In section 5.2, the commercial software, SAP2000, is used to simulate the responses of the 5-story model under various earthquake scenarios and compared the results with the experimental ones.

5.1 Shaking Table Tests

5.1.1 Description of Test Facilities

Model Structure The model structure for shaking table test is a 5-story steel

building (Fig. 5.1). The height of each story is 1.3 m except for the first story which is 1.5 m. The area of one level is 4 meter square. The smallest H-Beam (H100x50x5x7) commercially available is used to form the main frames of the building. Besides, two mass blocks (332 kg each) are installed on each floor to simulate the floor weight. The total weight of the model structure is about 4.14 ton, including the frame. Detailed properties of the model building are tabulated in table 5.1. System parameters that are listed in table 5.2 are obtained by using the processes of system identification [37].

Chapter 5 Seismic Performance Tests

71

Scale:1/30 Unit:cm

Tie Beam

Fig. 5.1 The model structure for shaking table test

Mode

1 2 3 4 5

Frequency (Hz)

1.46 4.57 7.85 11.01 13.47

Damping Ratio(%)

0.51 0.32 4.14 4.33 5.83

Table 5.1 Detailed properties of the model structure

Table 5.2 Natural Frequency and Damping Ratio of the Model Structure Extracted from System Identification Analysis

Length ( m ) 2 Width ( m ) 2 Height of 2~5 floors ( m ) 1.3

Height of 1^st floor ( m ) 1.5

m

₅(

kg

−

sec

²

m

) 82.28

m

₄(

kg

−

sec

²

m

) 84.75

m

₃(

kg

−

sec

²

m

) 84.75

m

₂(

kg

−

sec

²

m

) 84.75

m

₁(

kg

−

sec

²

m

) 85.13 Cross section of the column (

m m

) 100

×

⁵⁰

×

⁵

×

⁷

Cross section of the beam (

m m

) 100

×

50

×

5

×

7 Cross-sectional area of the column (

m

²) 0.0011

Cross-sectional area of the beam (

m

²) 0.0011

Chapter 5 Seismic Performance Tests

73

Earthquake Simulator The earthquake simulator designed by Prof. Yen-Po

Wang of National Chiao-Tung University (Fig. 5.2) is the first

“made-in-Taiwan” product of similar testing facility. It is primarily integrated from a 15-ton dynamic actuator of MTS (Model 244.23s, see Fig. 5.3) with a stainless steel table fabricated by a local supplier. The effective operating frequency of the hydraulic actuator is 50 Hz in accordance with the MTS specification. Therefore, a fundamental frequency higher than 100 Hz is desired for the table body to assure performance of the actuator. The ratio of the weight between the tested model and the table is suggested to be 2:1, at most, to avoid model-table interactions during the tests. Accordingly, a 3m×3m table of hollow box-like structure reinforced with ribs of steel plates is devised. The body is rigid enough against bending and torsion loads while with its weight minimized to 5 ton . As a result, the shaking table can accommodate a payload as much as 10-ton at a peak acceleration of 1.0 g. The maximum stroke of the shaking table is ±12.5 cm limited by the capacity of the actuator. With a piston area of 89

cm , the actuator operating under a

² 210

kg cm /

² working pressure can afford a maximum control force of 18.7

ton

, which is greater than what is required by driving the table in full loads at 1g acceleration. The flow rate required by driving the table at a speed of 60

cm

/ sec is 320

lpm

, which can be accommodated by the 3-stage servo valve (MTS Model 256.09) with a flow rate of 90

gpm

(340

lpm

). The shaking table system is facilitated with a 75

gpm

(283

lpm

) hydraulic pump (MTS Model 506.62), which is sufficient for an average flow requirement of 204

lpm

estimated by ²_π times the peak requirement (320

lpm

). The difference between the required and the average flow is supplemented or reserved by the accumulators (MTS Model 111).

Fig. 5.2 Earthquake simulator -- shaking table system

Fig. 5.3 15-ton dynamic actuator of MTS

Chapter 5 Seismic Performance Tests

75

Control and Data Acquisition System The MTS 407 Controller is adopted

as the control system of the shaking table. The 407 Controller accepts built-in waveforms as well as external input digital signals such as earthquake ground motion, which is converted into analog signals that, in turn, commands the hydraulic actuator to drive the shaking table via the servo valve. The shaking table system is also facilitated with a µ-Musycs system of IMC Corporation, German for data acquisition, by which at most synchronous measurement of 32 channels is available. The test data is recorded via a personal computer implemented with an Ethernet interface which allows for rapid data transfer and post processing on computers elsewhere.

Accelerometers Seven accelerometers of Crossbow (CXL04M1) with a

dynamic range of ±4g were used to measure the acceleration responses of the model structure in the direction of input ground motion during the tests. The accelerometers were implemented on each floor as well as the foundation beam.

Linear Variable Displacement Transducers LVDT of Kyowa (DLT-300AS)

with a dynamic range of ±30 cm was installed to measure the storydrift of the first floor during the tests.

5.1.2 Description of the Dampers

Totally 10 identical units of the metallic yielding damper (see Fig. 5.4 and Fig.

5.5) have been installed in the model structure in seismic performance tests, two for each story on the side frames parallel to the direction of earthquake ground motion (see Fig. 5.4). It is noted that over-design of the dampers will lead to amplification of the acceleration responses despite the displacement can be drastically reduced, while under-design of the dampers will provide only limited controlling effects, which may not be sufficient in severe earthquakes. Optimal design of the damping system for a prescribed structure is still a state-of-the-art.

The dimension of the damper was determined, based on preliminary parametric studies via computer simulations, to meet the design goal of suppression the acceleration and displacement responses of the structure simultaneously. Each unit of the damper consists of four X-shaped steel plates (1.5 mm thick each) as shown in Fig. 4.1. The plates with separation steel strips in between and two confining angle plates from the outside are bolted together through the preserved holes by a set of rods. The horizontal legs of the angle plates in turn serve as the interfaces for connecting the damper with the bracing system and the beam.

Chapter 5 Seismic Performance Tests

77

Fig. 5.4 Seismic performance test of the damper on a model structure via shaking table

Fig. 5.5 A close-up view of a unit of the damper on the model structure

5.1.3 Test Programs

The El Centro, Hachinohe earthquake and Kobe earthquake, that are selected as benchmark earthquake by the International Structural Control Society for earthquake engineering research, were considered in this series of tests as the input excitations with their intensity (in terms of Peak Ground Acceleration, PGA) scaled to various levels. The time histories of these earthquake records in full-scale is illustrated in Fig. 5.6, Fig. 5.7 and Fig. 5.8, respectively.

The model structure without implementation of the damper was first tested with the minimum earthquake intensity (PGA=0.1g) for each earthquake scenario. The seismic responses are then recorded as the basis for system identification of the model structure as well as comparison with those facilitated with the damper. The dynamic characteristics of the model structure extracted from the system identification analysis have been listed in Table 5.1 and 5.2 in the section 5.1. The model structure protected by the dampers was tested with the three benchmark earthquakes scaled from moderate to severe intensity levels.

Chapter 5 Seismic Performance Tests

79

0 1 2 3 4 5 6 7 8 9 10

−0.4

−0.3

−0.2

−0.1 0 0.1 0.2 0.3 0.4

Time (sec)

Ground Motion (g)

Fig. 5.6 Time history of El Centro earthquake

0 5 10 15

−0.5

−0.4

−0.3

−0.2

−0.1 0 0.1 0.2 0.3 0.4 0.5

Time (sec)

Ground Motion (g)

Fig. 5.7 Time history of Hachinohe earthquake

0 5 10 15 20 25 30 35 40 45 50

−0.8

−0.6

−0.4

−0.2 0 0.2 0.4 0.6 0.8

Time (sec)

Ground Motion (g)

Fig. 5.8 Time history of Kobe earthquake

5.1.4 Assessments of Seismic Performance

To prevent damage of the model structure, no tests with intensity larger than 0.1g have been conducted on the bare frame (i.e. without damper). The responses of the bare frame at greater intensities (PGA=0.2g, 0.3g and 0.4g for El Centro, PGA=0.15g, 0.2g and 0.25g for both Hachinohe and Kobe) presented in this section were obtained by linear extrapolation from the recorded results for PGA=0.1g. The testing results for the damper-protected structure were recorded directly.

Chapter 5 Seismic Performance Tests

81

El Centro Earthquake The comparisons of floor acceleration responses

under the El Centro earthquake are illustrated in Fig. 5.9 ~ 5.12 for intensities of 0.1g, 0.2g, 0.3g and 0.4g, respectively. As protected with damper, evident reductions of all the floor accelerations at various earthquake intensities have been observed. The peak floor responses at each testing scenario are summarized in Table 5.3. The peak accelerations are reduced except for 5F of PGA=0.1g, 0.2g, 0.3g and 0.4g, 2F of PGA=0.1g. The reduction of the 1^st floor peak acceleration in the case of PGA=0.1g is 16% and increased to 38% in the case of PGA=0.4g. The controlling effects of the damper system is even more pronounced as we look into the root-mean-squares (RMS) responses of the floor accelerations, as summarized in Table 5.4. The RMS responses are reduced except for 5F of PGA=0.1g. The reduction of the 5^th floor RMS acceleration in the case of PGA=0.2g is 18%, and increased to over 40% for higher intensities.

The comparison of the storydrift of the 1^st floor under the El Centro earthquake are illustrated in Fig. 5.13 ~ 3.16 for intensities of 0.1g, 0.2g, 0.3g and 0.4g, respectively. The controlling effects of the damper on the displacement responses have been achieved to a greater extent. The comparison of the root-mean-squares responses of the 1^st floor storydrift is summarized in Table 5.5. The reduction of the RMS response is 62% in the case of PGA=0.1g and increases for higher intensities.

The dynamic characteristics of the model structure in terms of the equivalent natural frequency and damping ratio of each mode under each testing scenario were determined, using the system identification technique from the test results, and summarized in Table 5.6. It is noted that the equivalent natural frequencies of the model structure decrease as the earthquake intensity increased, while the model damping ratios increase with the earthquake intensity. This is due to involvement of more inelastic behavior of the dampers for stronger earthquake. The natural frequencies of the structure have been increased as compared with those for the bare frame from Table 5.2 due to the added stiffness by the damper. The damping ratio of the 1^st mode was increased from 0.51% to 2.89% for PGA=0.1g and up to 7.49% for PGA=0.4g. Similar trends have been observed for the other modes.

Hachinohe Earthquake The comparisons of floor acceleration responses

under the Hachinohe earthquake are illustrated in Fig. 5.17 ~ 5.20 for intensities of 0.1g, 0.15g, 0.2g and 0.25g, respectively. As protected with damper, evident reductions of all the floor accelerations at various earthquake intensities have been observed, without exception. The peak floor responses at each testing scenario are summarized in Table 5.7. The reduction of the 5^th floor peak acceleration in the case of PGA=0.1g is 46%, and increased slightly for higher intensities. The reduction of the 1^st floor peak acceleration in the case of PGA=0.1g is 31% and increased to 49% in the case of PGA=0.25g. The controlling effects of the damper system is even more pronounced as we look into the root-mean-squares (RMS) responses of the floor accelerations, as summarized in Table 5.8. The reduction of the 5^th floor RMS acceleration in the case of PGA=0.1g is 54%, and increased to over 70% for higher intensities.

The comparison of the storydrift of the 1^st floor under the Hachinohe earthquake are illustrated in Fig. 5.21~3.24 for intensities of 0.1g, 0.15g, 0.2g and 0.25g, respectively. The controlling effects of the damper on the displacement responses have been achieved to a greater extent. The comparison of the root-mean-squares responses of the 1^st floor storydrift is summarized in Table 5.9. The reduction of the RMS response is 72% in the case of PGA=0.1g and 81% for higher intensities.

The dynamic characteristics of the model structure in terms of the equivalent natural frequency and damping ratio of each mode under each testing scenario were determined, using the system identification technique from the test results, and summarized in Table 5.10. It is noted that the equivalent natural frequencies of the model structure decrease as the earthquake intensity increased, while the model damping ratios increase with the earthquake intensity. This is due to involvement of more inelastic behavior of the dampers for stronger earthquake. The natural frequencies of the structure have been increased as compared with those for the bare frame from Table 5.2 due to the added stiffness by the damper. The damping ratio of the 1^st mode was increased from 0.51% to 4.79% for PGA=0.1g and up to 10.34%

for PGA=0.25g. Similar trends have been observed for the other modes.

Chapter 5 Seismic Performance Tests

83

Kobe Earthquake The comparisons of floor acceleration responses under

the Kobe earthquake are illustrated in Fig. 5.25 ~ 5.28 for intensities of 0.1g, 0.15g, 0.2g and 0.25g, respectively. Similarly, as protected with damper, evident reductions of all the floor accelerations at various earthquake intensities have been observed, without exception. The peak floor responses at each testing scenario are summarized in Table 5.11. The reduction of the 5^th floor peak acceleration in the case of PGA=0.1g is 45%, and increased slightly for higher intensities. The reduction of the 1^st floor peak acceleration in the case of PGA=0.1g is 21% and increased to 28% in the case of PGA=0.2g. The controlling effects of the damper system is even more pronounced as we look into the root-mean-squares (RMS) responses of the floor accelerations, as summarized in Table 5.12. The reduction of the 5^th floor RMS acceleration in the case of PGA=0.10g is 72%, and increased to 75% in the case of PGA=0.25g.

The comparison of the storydrift of the 1^st floor under the Hachinohe earthquake are illustrated in Fig. 3.29~3.32 for intensities of 0.1g, 0.15g, 0.2g and 0.25g, respectively. The controlling effects of the damper on the displacement responses have been achieved to a greater extent. The comparison of the root-mean-squares responses of the 1^st floor storydrift is summarized in Table 5.13. The reduction of the RMS response is 85% in the case of PGA=0.1g and 81% for higher intensities.

The dynamic characteristics of the model structure in terms of the equivalent natural frequency and damping ratio of each mode under each testing scenario were determined, using the system identification technique from the test results, and summarized in Table 5.14. It is noted that the equivalent natural frequencies of the model structure decrease as the earthquake intensity increased, while the modal damping ratios increase with the earthquake intensity. This again is due to involvement of more inelastic behavior of the dampers for stronger earthquake. The natural frequencies of the structure have been increased as compared with those for the bare frame from Table 2.2 due to the added stiffness by the damper. The damping ratio of the 1^st mode was increased from 0.51% to 7.56% for PGA=0.1g and up to 9.26%

for PGA=0.25g. Similar trends have been observed for the 2^nd mode.

-0.3 0.0 0.3

5F Ac cel er at io n ( g )

Experimental Acc.

El Centro 0.1g w/ USD Fixed

-0.3 0.0 0.3

4F A ccel er at io n (g )

-0.3 0.0 0.3

2F A cc ele ra ti on ( g )

-0.3 0.0 0.3

3F A ccel er at io n (g )

0 5 10 15 20

Time(sec) -0.3

0.0 0.3

1F A ccel er at io n (g )

Fig. 5.9 Comparison of floor acceleration responses (El Centro, PGA=0.1g)

w/ damper w/o damper

Chapter 5 Seismic Performance Tests

85

-0.3 0.0 0.3

5F Acceleration (g)

Experimental Acc.

El Centro 0.2g w/ USD Fixed

-0.3 0.0 0.3

4F Acceleration (g)

-0.3 0.0 0.3

2F Acceleration (g)

-0.3 0.0 0.3

3F Acceleration (g)

0 5 10 15 20

Time(sec) -0.3

0.0 0.3

1F Acceleration (g)

Fig. 5.10 Comparison of floor acceleration responses (El Centro, PGA=0.2g)

w/ damper w/o damper

0.5 0.0 -0.5

5F Acceleration (g)

Experimental Acc.

El Centro 0.3g w/ USD Fixed

-0.5 0.0 0.5

4F Acceleration (g)

-0.5 0.0 0.5

2F Acceleration (g)

-0.5 0.0 0.5

3F Acceleration (g)

0 10 20 30 40

Time(sec) -0.4

0.0 0.4

1F Acceleration (g)

Fig. 5.11 Comparison of floor acceleration responses (El Centro, PGA=0.3g)

w/ damper w/o damper

Chapter 5 Seismic Performance Tests

87

-0.5 0.0 0.5

5F Acceleration (g)

Experimental Acc.

El Centro 0.4g w/ USD Fixed

-0.5 0.0 0.5

4F Acceleration (g)

-0.5 0.0 0.5

2F Acceleration (g)

-0.5 0.0 0.5

3F Acceleration (g)

0 10 20 30 40

Time(sec) -0.5

0.0 0.5

1F Acceleration (g)

Fig. 5.12 Comparison of floor acceleration responses (El Centro, PGA=0.4g)

w/ damper w/o damper

0 10 20

Time (sec)

-1.0

0.0 1.0

1F D rif t (c m ) Fixed

w/ USD

Fig. 5.13 Comparison of storydrift of the 1st Floor (El Centro, PGA = 0.1g)

0 10 20

Time (sec)

-2.0

0.0 2.0

1F D rif t (c m ) Fixed

w/ USD

Fig. 5.14 Comparison of storydrift of the 1st Floor (El Centro, PGA = 0.2g)

w/ damper w/o damper

w/ damper w/o damper

Chapter 5 Seismic Performance Tests

89

0 10 20 30 40

Time (sec)

-3.0

0.0 3.0

1F D rif t (c m ) Fixed

w/ USD

Fig. 5.15 Comparison of storydrift of the 1st Floor (El Centro, PGA = 0.3g)

0 10 20 30 40

Time (sec)

-3.0

0.0 3.0

1F D rif t (c m ) Fixed

w/ USD

Fig. 5.16 Comparison of storydrift of the 1st Floor (El Centro, PGA = 0.4g)

w/ damper w/o damper

w/ damper w/o damper

-0.4 0.0 0.4

5F Acceleration (g)

Experimental Acc.

Hachinohe 0.1g w/ USD Fixed

-0.4 0.0 0.4

4F Acceleration (g)

-0.4 0.0 0.4

2F Acceleration (g)

-0.4 0.0 0.4

3F Acceleration (g)

0 4 8

Time(sec) -0.4

0.0 0.4

1F Acceleration (g)

Fig. 5.17 Comparison of Floor Acceleration Responses (Hachinohe, PGA = 0.1g)

w/ damper w/o damper

Chapter 5 Seismic Performance Tests

91

-0.5 0.0 0.5

5F A cc el era ti on (g )

Experimental Acc.

Hachinohe 0.15g w/ USD Fixed

-0.5 0.0 0.5

4F A cce le ra ti on ( g )

-0.5 0.0 0.5

2F A cc ele ra ti on (g )

-0.5 0.0 0.5

3F Ac ce le ra ti on (g )

0 5 10 15

Time(sec) -0.5

0.0 0.5

1F A cc el er atio n ( g )

Fig. 5.18 Comparison of Floor Acceleration Responses (Hachinohe, PGA = 0.15g)

w/ damper w/o damper

-0.8 0.0 0.8

5F A cc el er at io n ( g )

Experimental Acc.

Hachinohe 0.2g w/ USD Fixed

-0.8 0.0 0.8

4F Ac ce le ra ti on ( g )

-0.8 0.0 0.8

2F Ac ce le ra ti on ( g )

-0.8 0.0 0.8

3F A cc ele ra ti on (g )

0 5 10 15

Time(sec) -0.8

0.0 0.8

1F A cce le rat io n (g )

Fig. 5.19 Comparison of Floor Acceleration Responses (Hachinohe, PGA = 0.20g)

w/ damper w/o damper

Chapter 5 Seismic Performance Tests

93

-1.0 0.0 1.0

5F A cc el er at io n ( g )

Experimental Acc.

Hachinohe 0.25g w/ USD Fixed

-1.0 0.0 1.0

4F A cc ele ra tio n (g )

-1.0 0.0 1.0

2F A cc el er at io n (g )

-1.0 0.0 1.0

3F A ccele ra ti on ( g )

0 5 10 15

Time(sec) -1.0

0.0 1.0

1F A cc el er atio n (g )

Fig. 5.20 Comparison of Floor Acceleration Responses (Hachinohe, PGA = 0.25g)

w/ damper w/o damper

0 4 8

Time (sec)

-3.0 0.0 3.0

1F D rif t (c m ) Fixed

w/ USD

0 5 10 15

Time (sec)

-3.0 0.0 3.0

1F Dr if t (c m ) Fixed

w/ USD

w/ damper w/o damper

w/ damper w/o damper Fig. 5.21 Comparison of Storydrift of the 1st Floor

(Hachinohe, PGA = 0.1g)

Fig. 5.22 Comparison of Storydrift of the 1st Floor (Hachinohe, PGA = 0.15g)

Chapter 5 Seismic Performance Tests

95

0 5 10 15

Time (sec)

-4.0 0.0 4.0

1F Dr if t (c m ) Fixed

w/ USD

0 5 10 15

Time (sec)

-5.0 0.0 5.0

1F Dr if t (c m ) Fixed

w/ USD

w/ damper w/o damper

w/ damper w/o damper Fig. 5.23 Comparison of Storydrift of the 1st Floor

(Hachinohe, PGA = 0.2g)

Fig. 5.24 Comparison of Storydrift of the 1st Floor (Hachinohe, PGA = 0.25g)

-0.4 0.0 0.4

5F A cce le ra ti on (g )

Experimental Acc.

Kobe 0.1g w/ USD Fixed

-0.4 0.0 0.4

4F A cce le ra ti on ( g )

-0.4 0.0 0.4

2F A cc el era ti on (g )

-0.4 0.0 0.4

3F A cc ele ra ti on ( g )

0 5 10 15 20 25

Time(sec) -0.4

0.0 0.4

1F A cc el era ti on (g )

Fig. 5.25 Comparison of Floor Acceleration Responses (Kobe, PGA = 0.1g)

w/ damper w/o damper

Chapter 5 Seismic Performance Tests

97

-0.5 0.0 0.5

5F A cc el era ti on (g )

Experimental Acc.

Kobe 0.15g w/ USD Fixed

-0.5 0.0 0.5

4F Accel er at io n ( g )

-0.5 0.0 0.5

2F A cc ele ra tio n ( g )

-0.5 0.0 0.5

3F A cc el era ti on (g )

0 5 10 15 20 25

Time(sec) -0.5

0.0 0.5

1F A cc el era ti on (g )

Fig. 5.26 Comparison of Floor Acceleration Responses (Kobe, PGA = 0.15g)

w/ damper w/o damper

-0.8 0.0 0.8

5F A cc el era ti on (g )

Experimental Acc.

Kobe 0.2g w/ USD Fixed

-0.8 0.0 0.8

4F Ac cel er at io n (g )

-0.8 0.0 0.8

2F A cce ler at io n ( g )

-0.8 0.0 0.8

3F Ac cel er at io n (g )

0 5 10 15 20 25

Time(sec) -0.8

0.0 0.8

1F A ccel er at io n (g )

Fig. 5.27 Comparison of Floor Acceleration Responses (Kobe, PGA = 0.2g)

w/ damper w/o damper

Chapter 5 Seismic Performance Tests

99

-0.8 0.0 0.8

5F Acceleration (g)

Experimental Acc.

4F Acceleration (g)

-0.8 0.0 0.8

2F Acceleration (g)

-0.8 0.0 0.8

3F Acceleration (g)

0 5 10 15 20 25

Time(sec) -0.8

0.0 0.8

1F Acceleration (g)

w/ USD w/o USD

Fig. 5.28 Comparison of Floor Acceleration Responses (Kobe, PGA = 0.25g)

w/ damper w/o damper

w/ damper w/o damper

w/ damper w/o damper Fig. 5.29 Comparison of Storydrift of the 1st Floor

(Kobe, PGA = 0.1g)

Fig. 5.30 Comparison of Storydrift of the 1st Floor (Kobe, PGA = 0.15g)

Chapter 5 Seismic Performance Tests

101

w/ damper w/o damper

w/ damper w/o damper Fig. 5.31 Comparison of Storydrift of the 1st Floor

(Kobe, PGA = 0.2g)

Fig. 5.32 Comparison of Storydrift of the 1st Floor (Kobe, PGA = 0.25g)

Table 5.3 Comparison of Peak Floor Acceleration Responses in the El Centro Series of Tests

Input = El Centro Earthquake

PGA = 0.1g PGA = 0.2g

Chapter 5 Seismic Performance Tests

103

Table 5.4 Comparison of Root-Mean-Squares Floor Acceleration In the El Centro Series of Tests

Input = El Centro Earthquake

PGA = 0.1g PGA = 0.2g

Table 5.5 Root-Mean-Squares of 1st Floor Storydrift In the El Centro Series of Tests

Input= El Centro Earthquake RMS Response of Storydrift

(cm)

Table 5.6 Equivalent Natural Frequency and Damping Ratio of the damper-Protected Model Structure

El Centro Earthquake Record

PGA = 0.1g PGA = 0.2g PGA = 0.3g PGA = 0.4g

Chapter 5 Seismic Performance Tests

105

Table 5.7 Comparison of Peak Floor Acceleration Responses in the Hachinohe Series of Tests

Input = Hachinohe Earthquake

PGA = 0.10g PGA = 0.15g

Table 5.8 Comparison of Root-Mean-Squares Floor Acceleration In the Hachinohe Series of Tests

Input = Hachinohe Earthquake

PGA = 0.10g PGA = 0.15g

Chapter 5 Seismic Performance Tests

107

Table 5.9 Root-Mean-Squares of 1st Floor Storydrift In the Hachinohe Series of Tests

Input= Hachinohe Earthquake RMS Response of Storydrift

(cm)

Table 5.10 Equivalent Natural Frequency and Damping Ratio of the damper-Protected Model Structure

Hachinohe Earthquake Record

PGA = 0.1g PGA = 0.15g PGA = 0.2g PGA = 0.25g

Table 5.11 Comparison of Peak Floor Acceleration Responses in the Kobe series Tests

Input = Kobe Earthquake

PGA = 0.10g PGA = 0.15g

Chapter 5 Seismic Performance Tests

109

Table 5.12 Comparison of Root-Mean-Squares Floor Acceleration for Kobe Series of Tests

Input = Kobe Earthquake

PGA = 0.1g PGA = 0.15g

Table 5.13 Root-Mean-Squares of 1st Floor Storydrift for Kobe Series of Tests

RMS of 1F Drift for Kobe Earthquake Record (cm) RMS of 1F Drift (cm)

Table 5.14 Equivalent Natural Frequency and Damping Ratio of the damper-Protected Model Structure

Kobe Earthquake Record

PGA = 0.1g PGA = 0.15g PGA = 0.2g PGA = 0.25g

Chapter 5 Seismic Performance Tests

111

5. 2 Numerical Simulation Using SAP2000

SAP2000 is a powerful analysis software widely used in structural engineering.

It offers the following analysis features [38]:

x Static and dynamic analysis x Linear and nonlinear analysis

x Dynamic seismic analysis and static pushover analysis x Frame and shell structural elements

x Two-dimensional plane and axisymmetric solid elements x Three-dimensional solid elements

x Nonlinear link and spring elements x Multiple coordinate systems x Many types of constraints

x A wide variety of loading options

x A wide variety of loading options

在文檔中 金屬消能制震板之理論分析與實驗 (頁 81-0)