第五章 結論與建議
5.2 建議
時變系統之識別上,以移動最小平方差法架構TVARX 模式對於跳耀變 化之時變系統之識別效果不盡理想,未來研究可進一步探討不同權重函數 對識別結果之影響。
在局部動態識別中,須以識別之自由度以及相鄰之自由度之資料進行 識別;而在現地量測時,每個自由度資料並不是相當齊全,未來之研究可 探討如何在不完全自由度之下進行局部動態識別。
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表 4.1:鋼構之材料性質
Dir-2m Dir-3m
Column(1F~5F) H125x125x6.5x9 H125x125x6.5x9 Beam(1F~5F) H150x75x5x7 H100x100x6x8 Girder(1F~5F) H100x50x5x7 H100x50x5x7
表 4.2:六層樓所識別之案例
Test No. Excitation case PGA(ideal) Direction Description Remarks
Case 1 White Noise 50 gal x
Case 2 White Noise 100 gal x
Case 3 El Centro 100 gal x
With no cuts
Strain Gauges were not mounted. DX0
was not ready for service. The disp. of
shaking table (Long Dis) is used instead.
Case 4 White Noise 50 gal x
Case 5 White Noise 100 gal x
Case 6 El Centro 100 gal x
Damage scenario 1 *:
A cut with 3.75cm deep at the medium height of each of the
two south-side columns in 1st floor (with Strain gauges 7
and 8).
Strain Gauges were mounted.
Case 7 White Noise 50 gal x
Case 8 White Noise 100 gal x
Case 9 El Centro 100 gal x
Case 10 El Centro 500 gal x
Damage scenario 2 *:
A cut with 7.5cm deep at the medium
height of each
columns in 1st floor
表 4.3:case1、case2 與 case3 試驗之識別結果變化區間
表 4.4:case4、case5 與 case6 試驗之識別結果變化區間
表 4.5:case7、case8、case9 與 case10 試驗之識別結果變化區間
圖 3.1:三層樓剪力構架示意圖
圖 3.2:平滑變化時變系統之理論模態
0 5 10 15 20 25 30
(m/sec²)/Hz*9.8² (m²/sec)/Hz(m²/sec)/Hz(m²/sec)/Hz
1st mode
2nd mode
3rd mode
圖 3.5:以 921 地震輸入對平滑變化之時變系統識別結果
1st mode
2nd mode
3rd mode
圖 3.6:各組支撐參數(
d
m)於不同節點數下之識別誤差圖 3.7:以 921 地震輸入對平滑變化之時變系統識別之 MAC 圖
圖 3.8:加入 5%噪訊比之輸入及頻譜圖
圖 3.9:加入 5%噪訊比每個自由度之位移輸出反應及其頻譜圖
(m/sec²)/Hz*9.8² (m²/sec)/Hz(m²/sec)/Hz(m²/sec)/Hz
1st mode
2nd mode
3rd mode
圖 3.10:以 921 地震輸入加入噪訊比 5%對平滑變化之時變系統識別結果
1st mode
2nd mode
3rd mode
圖 3.11:各組支撐參數(
d
m)與不同節點數在模型階數( , )I J
為(15,15)之識別 誤差圖 3.12:利用不同階數分析含雜訊反應於不同時間點所得之瞬時頻率 (
l
n=10,d
m=4)圖 3.13:利用不同階數分析含雜訊反應於不同時間點所得之瞬時頻率 (
l
n=20,d
m=4)圖 3.14:利用不同階數分析含雜訊反應於不同時間點所得之瞬時頻率 (
l
n=30,d
m=4)圖 3.16:以 921 地震輸入加入噪訊比 5%之 MAC 圖
(a)
(b)
(c)
圖 3.17:各子結構系統之理論瞬時擬自然振動頻率及阻尼比
(a)
(b)
(c)
圖 3.18:各子結構系統之識別結果
圖 4.1:國家地震工程研究中心之五層樓鋼構架
圖 4.2:國家地震工程研究中心之六層樓鋼構架
圖 4.3:五層樓鋼構架之上視平面圖
圖 4.4:五層樓鋼構架之側視平面圖
3000mm
2000mm Beam
Girder
Column Beam
2000mm 3000mm
5 @ 13 00 mm 5 @ 13 00 mm
DOF
5 1
2
3
4
圖 4.5:10%Kobe 地震輸入反應及其頻譜圖
(m/sec ²)/Hz * 9 .8 ²
圖 4.6:10%Kobe 地震作用下各樓層之位移反應圖
圖 4.7:10%Kobe 地震作用下各樓層之位移頻譜圖
(m ²/sec)/Hz (m ²/sec)/Hz (m ²/sec)/Hz (m ²/sec)/Hz (m ²/sec)/Hz
圖 4.8:60%Kobe 地震輸入反應及其頻譜圖
(m/sec ²)/Hz * 9 .8 ²
圖 4.9:60%Kobe 地震作用下各樓層之位移反應圖
圖 4.10:60%Kobe 地震作用下各樓層之位移頻譜圖
(m ²/sec)/Hz (m ²/sec)/Hz (m ²/sec)/Hz (m ²/sec)/Hz (m ²/sec)/Hz
圖 4.11:10%與 60%Kobe 地震下最底層柱之應變歷時圖
圖 4.12:10% Kobe 地震下各自由度之識別瞬時動態特性
(圖 4.12 續上頁)
圖 4.13:10% Kobe 地震下各模態之 MAC 以及 e 值
(圖 4.13 續上頁)
圖 4.14:60% Kobe 地震下各自由度之識別瞬時動態特性
(圖 4.14 續上頁)
圖 4.15:60% Kobe 地震下各模態之 MAC 以及 e 值
(圖 4.15 續上頁)
(a) (b)
(c) (d)
圖 4.16:五層樓各個自由度之局部動態識別
圖 4.17:六層樓鋼構架之側視圖
圖 4.18:六層樓鋼構架之立體圖
圖 4.19:Damage Scenario 1
圖 4.20:Damage Scenario 2
Reduced section
Reduced
section
圖 4.21:在最底層實驗示意圖
Y X
(a) (North-East Corner) (b) (South-East Corner)
(c) (South-West Corner) (d) (North-West Corner) 圖 4.22:case 9 與 case 10 試驗中最底層柱之應變歷時
圖 4.23:case 3 試驗中輸入歷時及其頻譜
(mm/sec ²) /H z*9 800 ²
圖 4.24:case 3 試驗中各樓層之位移反應
圖 4.25:case 6 試驗中輸入歷時及其頻譜
(mm/sec ²) /H z*9 800 ²
圖 4.26:case 6 試驗中各樓層之位移反應
圖 4.27:case 9 試驗中輸入歷時及其頻譜
(mm/sec ²) /H z*9 800 ²
圖 4.28:case 9 試驗中各樓層之位移反應
圖 4.29:case10 試驗中輸入歷時及其頻譜
(mm/sec ²) /H z*9 800 ²
圖 4.30:case10 試驗中各樓層之位移反應
1st floor
2nd floor
3rd floor
圖 4.31:case 3、case 6、case9 與 case 10 試驗中各樓層之位移頻譜
4th floor
5th floor
6th floor
(圖 4.31 續上頁)
1st mode
2nd mode
3rd mode
圖 4.32:case1、case2 和 case3 試驗識別之結果
4th mode
5th mode
6th mode
(圖 4.32 續上頁)
1st mode
2nd mode
3rd mode
圖 4.33:case1、case2 和 case3 試驗各模態之 MAC 以及 e 值
4th mode
5th mode
6th mode
(圖 4.33 續上頁)
1st mode
2nd mode
3rd mode
圖 4.34:case4、case5 和 case6 試驗識別之結果
4th mode
5th mode
6th mode
(圖 4.34 續上頁)
1st mode
2nd mode
3rd mode
圖 4.35:case4、case5 和 case6 試驗各模態之 MAC 以及 e 值
4th mode
5th mode
6th mode
(圖 4.35 續上頁)
1st mode
2nd mode
3rd mode
圖 4.36:case7、case8 、case9 和 case10 試驗識別之結果
4th mode
5th mode
6th mode
(圖 4.36 續上頁)
1st mode
2nd mode
3rd mode
圖 4.37:case7、case8、case9 和 case10 試驗各模態之 MAC 以及 e 值
4th mode
5th mode
6th mode
(圖 4.37 續上頁)
(a)
(b)
(c)
圖 4.38:六層樓各個自由度之局部動態識別