teacherteacher

網站管理小編

第三十五卷第三期 (期別137) (109年)

作者:

第三十五卷第三期(期別137)(109年)

標題SM570M-CHW 高強度鋼箱型柱翼厚與梁翼板高程偏心對電熱熔渣銲破壞效應
作者黃昱竣、胡祐瑋、覃志光、蔡青宜、李昭賢、莊勝智、 林克強、蔡克銓
關鍵字鋼箱型柱、鋼梁柱接頭、SM570M-CHW 鋼、電熱熔渣銲、圓周刻痕拉伸試驗、鋼材破裂預測模型、有限元素模型分析、橫隔梁翼交疊高度
摘要箱型柱具雙強軸特性，在台灣鋼結構中應用普遍，為將梁彎矩傳入柱構件，箱型柱中與梁翼相對應之高程須置入內橫隔板，內橫隔板與箱型柱之銲接工法通常採用電熱熔渣銲（Electro-Slag Welding, ESW），而為減少柱斷面積，高強度 SM570M-CHW 鋼的應用也漸普及。本研究利用高強度鋼材探討箱型柱中 ESW 的耐震行為，並採用既有的鋼材破壞預測模型探討ESW 是否會破裂與破裂時機。本研究以 11 組 ESW 元件單向拉伸試驗與 4組實尺寸梁柱接頭反覆載重試驗探討柱翼板厚度與梁翼板偏心對於 ESW 破壞的效應，試驗結果顯示 ESW 元件僅受單向拉力作用時，只要「梁翼橫隔交疊高度」小於等於零，且偏心大於一倍柱翼板厚度，ESW 就會發生破壞；但「梁翼橫隔交疊高度」大於或等於 1/4 梁翼厚時，偏心超過一倍柱翼板厚度仍不會於 ESW 發生破壞。實尺寸梁柱接頭反覆載重試驗中則證明當柱翼板厚度由 25mm 提升至 45mm 時，ESW 由原先 3%層間位移角發生破壞改善至層間位移角達 5%尚未發生破壞。為探討 ESW 元件能否有效模擬梁柱接頭中的 ESW 銲道受力行為，本研究亦建立圓周刻痕試棒有限元素模型獲得材料參數之後，再進行 ESW 元件有限元素模型分析，並進行 ESW 關鍵區域破裂預測，結果顯示不論梁翼對 ESW 往梁腹方向亦或是反向偏心，有限元素模型皆能預測出 ESW 元件試體破壞時機且誤差小於 12%；進而建立實尺寸梁柱接頭有限元素模型模擬接頭內 ESW 銲道在反覆載重作用下之受力行為，結果顯示當柱翼板厚度由 25mm 增厚至 45mm 時，應力集中現象明顯減緩，且尖端開口位移下降至原先 1/3 倍，並可準確預測梁柱接頭內ESW 破壞時機。本研究亦以柱翼板厚度、梁翼板厚度及橫隔梁翼交疊高度為參數進行研究，探討不同參數配置對 ESW 銲道關鍵區域破壞時機之影響。分析結果顯示，當柱翼板厚度與橫隔梁翼交疊高度提升，以及梁翼板厚度減少時，可降低 ESW 開裂之機會。本研究建議柱翼板厚度宜大於或等於橫隔板厚度，且橫隔梁翼交疊高度不宜低於四分之一倍之橫隔板厚度，以避免 ESW 之脆性破壞。
TitleEffects of SM570M-CHW steel beam flange eccentricity and box-column flange thickness on electro-slag welding failure
AuthorYu-Jun Huang, You-Wei Hu, Chih-Kuang Chin, Ching-Yi Tsai, Chao-Hsien, Li,Sheng-Jhih Jhuang, Ker-Chun Lin, Keh-ChyuanTsai
Keywordssteel box column, SM570M-CHW steel, electro-slag welding, circumferentially notched tensile test, steel fracture prediction model, finite element analysis, overlapping distance of beam flange and diaphragm
AbstractSteel box columns are widely used in seismic steel building structures in Taiwan. In order to effectively transfer the beam-end moment to the column, diaphragm plates are welded inside the box column at the same elevations of the welded beam flanges. Electro-slag welding (ESW) procedure is common applied to attach the diaphragm plates to the column. Recently, the SM570M-CHW grade high strength steel is prevailingas it reduces the column sizes. In this study, four full-scaled welded SM570M-CHW steel beam-to-column (BC)joint specimens and eleven ESW component specimens were fabricated and tested. The key design parameters of these specimens include column flange thickness, beam flange eccentricity with respect to the diaphragm plate. This study investigates the applicability of stress modified critical strain and degraded significant plastic strain modelsin predicting the crack initiation fracture of the diaphragm-to-column ESW joint. The ESW component specimens were subjected to monotonic tensile loads, while the welded BC joint specimenswere subjected to cyclically increasing displacement to investigate the effects of beam flange eccentricity and column flange thickness on the ESW fractures. Test results show that when the ESW was subjected to monotonic tension only, it could fracture when the “overlapping distance of beam flange and diaphragm” (OD) was smaller or equal to zero. On the contrary, it remained intact even when the ODwas greater or equal to thickness of beam flange. Cyclic test results of the welded BC joints show that the connection with the 25mm thick column flange failed at the 3% inter-story drift (IDR) cycle, while the specimen with the 45mm column flange went through 5% IDR cycle without failure. The finite element model analysisresults show that when the column flange thickness increases from 25mm to 45mm, the stress concentrations are reduced and the crack tip opening displacement is decreased by 3 times. This study also carried out parametric study, focusing on the effects of the column flange thickness, the beam flange thickness and the OD on ESW fracture. Results show that increasing the column flange thickness, or the OD and decreasing the beam flange thickness reduce the stress concentration near ESW. In order to avoid the ESW fracture, the results of this study suggest that column flange thickness be equal to or larger than diaphragm or beam flange thickness; and the ODbe larger than one quarter of the diaphragm or beam flange thickness.
標題地動特性預測模組與智慧型隔減震控制系統之研發
作者蕭迦恩、林光奕、林子剛、 盧煉元
關鍵字地表運動特性，支持向量機，隔減震控制，基因演算法，模糊控制
摘要近年來隔減震控制與地震預警的研究愈加受到重視，在地震工程領域中，地表運動特性除了常見的加速度、速度與位移的極值，還可分類為近斷層地表運動(near-fault ground motion)與遠域地表運動(far-field ground motion)。根據過去結構隔減震控制的相關研究，不同地表運動特性對於結構反應之控制結果影響甚鉅，故此研究試圖提出地表運動特性之預測模組，於地震主震波到來前預測此地震之地表運動特性，以優化隔減震之即時控制成效。本研究建立近斷層地表運動與遠域地表運動之資料庫，利用六項初達波特徵參數以及地表動態頻譜的高頻能量累加參數，以監督式機器學習—支持向量機建立地表運動特性預測模組。為了進一步開發智慧型隔減震即時控制系統，研究中採用槓桿式可變勁度隔震系統(Leverage-type Stiffness Controllable Isolation System, LSCIS)作為隔減震原型機構，此半主動控制機構可透過調整其控制律之控制參數，改變有效隔震勁度以即時控制結構動態反應。本研究亦將數個相異類型且具指標性的地表運動所對應之控制參數透過基因演算法最佳化，並以模糊控制建立地表運動與控制參數之關係模型，開發出智慧型隔減震即時控制系統。
TitleDevelopment of Ground Motion Characteristics Prediction Module and its Application to the Control of Intelligent Isolation System
AuthorChia-En Hsiao, Kuang-Yi Lin, Tzu-Kang Lin, Lyan-Ywan Lu
KeywordsGround motion characteristics, Support vector machine, Structural control, Genetic algorithm, Fuzzy control.
AbstractIn recent years, researches on structural control combining earthquake early warning have been widely studied. In the field of seismic engineering, ground motions can be mainly classified into near-fault and far-field ground motions. While the ground motion characteristics have a great influence on control performance; however, the existing earthquake early warning system can only predict the peak ground acceleration, and the optimal control efficiency cannot be promptly achieved. Therefore, a prediction module for ground motion characteristics is proposed in this study. A database of near-fault ground motions and far-field ground motions is first collected, and the six p-wave features and the high-frequency energy accumulations of the ground dynamic spectrum are used to establish the ground motion characteristic prediction module by utilizing support vector machine. In order to develop the intelligent structural control system, the Leverage-type Stiffness Controllable Isolation System (LSCIS) is used as the structural control mechanism. The effective isolation stiffness of the LSCIS can be swiftly changed to control the dynamic response of the structure. The control parameters corresponding to different types of ground motion are optimized by genetic algorithm, and fuzzy control is adopted for the intelligent isolation system.
標題壓電調諧質量阻尼器於垂直振動減振與能量擷取
作者賴勇安、周維苓、鍾立來
關鍵字調諧質量阻尼器、壓電材料、能量擷取、垂直振動、最佳化設計
摘要近年來人類對於能源的需求持續攀升，然而為因應氣候變遷，將迫使減少石化能源的使用，因此尋求更多更環保的能量來源，以因應未來需求，為當前各國的研究重點之一。由於土木結構與材料技術的發展，結構物設計建造越趨經濟，橋梁結構重量漸趨輕量，外觀也逐趨細長，結構週期也隨之延長，使得橋梁結構也較易受人行等外力激振。土木工程師為了有效降低此振動量，逐以加裝調諧質量阻尼器（Tuned Mass Damper, TMD）的方式，透過調諧質量阻尼器的振動頻率與結構自然頻率調諧，吸收結構的振動能量，並透過自身之阻尼器來消散傳入之振動能。然此能量為一綠色能源，如能量就此消散，實為浪費，有鑑於此，本文研究「壓電調諧質量阻尼器 (Piezoelectric Tuned Mass Damper, Piezo-TMD)」，以壓電材料將吸收之機械振動能轉換為電能，以便進行能量擷取。本文首先提出壓電調諧質量阻尼器之模型，推導出壓電調諧質量阻尼器系統之運動方程式。與一般調諧質量阻尼器不同，壓電調諧質量阻尼器除了力學之運動方程式外，另有一電路方程式，且兩方程式互為耦合。本文之壓電調諧質量阻尼器設計目標為能量擷取的平均功率最大化，並以一人行橋結構進行數值模擬，結果顯示壓電調諧質量阻尼器具有與傳統調諧質量阻尼器相近之結構減振效果，並可將人行外力所引致之振動能轉為可再利用之電能。且模擬結果顯示，壓電調諧質量阻尼器除其機械之自然頻率需與結構相調諧外，其電路之自然頻率也需與結構調諧，方可使結構之振動能量有效利用共振效應轉移至電路上。
TitlePiezoelectric Tuned Mass Damper for Vertical Vibration Reduction and Energy Harvesting
AuthorYong-An Lai, Wei-Ling Chou, Lap-Loi Chung
Keywordstuned mass damper, piezoelectric material, energy harvesting, vertical vibration reduction, optimal design
AbstractIn recent years, the energy consumption has continually grown. However, due to climate change, the use of fossil fuel to generate electrical power forces to be reduced. Therefore, looking for environmental friendly energy sources is one of the current research priorities. Because of the development of civil engineering technology, the design and construction of structures turn into more economical. The weight of the bridge structure is becoming lighter, the appearance is accomplishing slender, and the structural period is therefore prolonged, making the bridge structure more susceptible to external forces such as pedestrian loads. In order to effectively reduce the vibration, civil engineers designed and installed Tuned Mass Damper (TMD). Through the tuning of the natural frequency of TMD to the structure, the vibration energy of the structure was absorbed and then dissipated by dashpot. However, this absorbed energy is a kind of green energy source to waste to be dissipated. In view of this, this article studies “Piezoelectric Tuned Mass Damper (Piezo-TMD)”, which uses piezoelectric materials to convert the mechanical vibration energy into electricity for energy harvesting. This research proposes the model and derives the equation of motion of the Piezo-TMD system. Different from the conventional TMD, Piezo-TMD has a circuit equation in addition to the mechanical equation, and these two equations are mutually coupled. The design goal of the Piezo-TMD in this paper is to maximize the average power for energy harvesting, and the numerical simulations are carried out with a pedestrian bridge structure. The simulation results show that the Piezo-TMD achieves the similar performance of vibration reduction as the conventional TMD and thus the vibration comfort requirement can be satisfied. Moreover, the vibration energy is further transferred to electricity for harvest to verify the feasibility of Piezo-TMD. In addition to tuning the mechanical natural frequency of the Piezo-TMD, the natural frequency of the circuit also needs to be tuned to the structure, so that the vibration energy of the structure can be effectively transferred to the circuit by using the resonance effect.
標題五螺箍筋柱之雙曲率反覆載重試驗與離散計算剪力模型
作者歐昱辰、李哲諺
關鍵字剪力強度、五螺箍、柱、離散計算剪力模型、反覆載重
摘要五螺箍筋運用在正方形斷面鋼筋混凝土柱已證實具有優於傳統方箍筋的圍束能力。本研究目的在於探討五螺箍筋之剪力強度，設計雙曲率反覆載重試驗，測試大型剪力破壞五螺箍柱與傳統方箍柱對照組。測試結果指出，箍筋體積比相同、鋼筋降伏強度與混凝土抗壓強度相似的情況下，五螺箍柱展現稍弱於傳統方箍柱的極限剪力強度，所有五螺箍柱過最大剪力強度後力量衰退速率皆小於傳統方箍柱。高軸力五螺箍柱之破壞模式為箍筋拉斷，而高軸力傳統方箍柱之破壞模式為彎鉤鬆脫導致過早破壞。本研究發展一套改進離散計算剪力模型用來計算五螺箍柱剪力強度。與試驗結果比較，改進離散計算剪力模型能保守估計五螺箍剪力強度，此外，本模型具有與規範剪力公式用於傳統方箍剪力強度之相似保守程度。
TitleDouble-curvature cyclic test of columns with five-spiral reinforcement and discreet computational shear strength model
AuthorYu-Chen Ou and Jhe-Yan Li
Keywordsshear strength; five-spiral reinforcement; columns; discreet computational shear strength model; cyclic test.
AbstractFive-spiral reinforcement has been proved to have superior confinement capability to conventional rectilinear hoops. The objective of this research is to investigate the shear strength of five-spiral reinforcement. Large-scale columns with five-spiral reinforcement and control columns with conventional rectilinear reinforcement were tested in this research using double-curvature cyclic loading. Test results showed that with the same volume of reinforcement and similar reinforcement yield strength and concrete compressive strength, the shear strength of columns with five-spiral reinforcement was slightly less than that with conventional rectilinear reinforcement. However, the strength degradation after the peak strength for columns with five-spiral reinforcement was slower than that for columns with conventional rectilinear reinforcement. Under high axial load, the failure mode of columns with five-spiral reinforcement was fracture of spirals.In contrast, the failure mode of columns with conventional rectilinear reinforcement was the loosening of hook anchorage of the reinforcement. An improved discreet computational shear strength model is developed in this research and validated by the test results. The model can be conservatively used for estimating the shear strength of five-spiral reinforcement. Moreover, the model shows a conservatism for estimating the shear strength of five-spiral reinforcement similar tothat shown by the code shear strength equations for conventional rectilinear reinforcement.
標題結合振形之微振索力估算法中量測點位配置對精度的影響
作者陳建州、吳文華、陳欣怡、 賴國龍
關鍵字微振法、索力估算、振形、有效振動長度、多點同步量測、量測點位配置
摘要為克服複雜錨定條件造成微振索力估算法的較大誤差問題，本研究團隊近年來提出一項創新的方法，藉由導入振形函數正弦分量的擬合來決定各振態有效振動長度以排除索力計算公式中複雜邊界條件的影響，而其關鍵則在如何經由多點同步量測精準重現振形函數之正弦分量。本文首先根據理論推導出的頻率方程式與振形函數闡述此一索力量測方法的基本原理；接著再進一步利用有限元素模型，於考慮實測作業限制條件下建立包括數目與間距等量測點位配置準則；最後則進行實驗室單根鋼絞線索力量測，充分驗證所擬定量測點位配置準則的適用性以及對應的索力估算精度。
TitleEffect of sensor deploymentonen on the accuracy of ambient vibration method incorporating mode shape functions for cable tension estimation
AuthorChien-Chou Chen, Wen-Hwa Wu, Shin-Yi Chen and Gwolong Lai
Keywordsambient vibration method, cable tension estimation, mode shape, effective vibration length, multiple synchronous measurements, sensor deployment
AbstractThe complicated boundary conditions resulted from the anchorage systems at both ends usually deteriorate the accuracy of the ambient method for cable tension estimation. Motivated by tackling such a problem, a novel method incorporating the mode shape functions was recently proposed by this research group. More specifically, the fitting for the sinusoidal components of mode shape functions was adopted to determine the effective vibration length for each mode such that the interference from the complicated boundary conditions can be eliminated. The success of this method is most critically decided by the accurate reproduction of the sinusoidal components of mode shape functions based on multiple synchronous measurements. The current paper first explains the basic concepts of this cable tension estimation method with the theoretically derived mode shape functions and frequency equations. The finite element models are further employed to evaluate the accuracy of this method and establish the guidelines for the preferred sensor deployment in measurement points and spacing with the consideration of practical measurement limitations. Finally, the applicability of the developed guidelines and the corresponding accuracy in tension estimation are verified by demonstrative laboratory experiments with a prestressed strand.

Vol.35/No.3 (137) (2020)

作者:

Vol.35/No.3 (137) (2020)

TitleEffects of SM570M-CHW steel beam flange eccentricity and box-column flange thickness on electro-slag welding failure
AuthorYu-Jun Huang, You-Wei Hu, Chih-Kuang Chin, Ching-Yi Tsai, Chao-Hsien, Li,Sheng-Jhih Jhuang, Ker-Chun Lin, Keh-ChyuanTsai
Keywordssteel box column, SM570M-CHW steel, electro-slag welding, circumferentially notched tensile test, steel fracture prediction model, finite element analysis, overlapping distance of beam flange and diaphragm
AbstractSteel box columns are widely used in seismic steel building structures in Taiwan. In order to effectively transfer the beam-end moment to the column, diaphragm plates are welded inside the box column at the same elevations of the welded beam flanges. Electro-slag welding (ESW) procedure is common applied to attach the diaphragm plates to the column. Recently, the SM570M-CHW grade high strength steel is prevailingas it reduces the column sizes. In this study, four full-scaled welded SM570M-CHW steel beam-to-column (BC)joint specimens and eleven ESW component specimens were fabricated and tested. The key design parameters of these specimens include column flange thickness, beam flange eccentricity with respect to the diaphragm plate. This study investigates the applicability of stress modified critical strain and degraded significant plastic strain modelsin predicting the crack initiation fracture of the diaphragm-to-column ESW joint. The ESW component specimens were subjected to monotonic tensile loads, while the welded BC joint specimenswere subjected to cyclically increasing displacement to investigate the effects of beam flange eccentricity and column flange thickness on the ESW fractures. Test results show that when the ESW was subjected to monotonic tension only, it could fracture when the “overlapping distance of beam flange and diaphragm” (OD) was smaller or equal to zero. On the contrary, it remained intact even when the ODwas greater or equal to thickness of beam flange. Cyclic test results of the welded BC joints show that the connection with the 25mm thick column flange failed at the 3% inter-story drift (IDR) cycle, while the specimen with the 45mm column flange went through 5% IDR cycle without failure. The finite element model analysisresults show that when the column flange thickness increases from 25mm to 45mm, the stress concentrations are reduced and the crack tip opening displacement is decreased by 3 times. This study also carried out parametric study, focusing on the effects of the column flange thickness, the beam flange thickness and the OD on ESW fracture. Results show that increasing the column flange thickness, or the OD and decreasing the beam flange thickness reduce the stress concentration near ESW. In order to avoid the ESW fracture, the results of this study suggest that column flange thickness be equal to or larger than diaphragm or beam flange thickness; and the ODbe larger than one quarter of the diaphragm or beam flange thickness.
TitleDevelopment of Ground Motion Characteristics Prediction Module and its Application to the Control of Intelligent Isolation System
AuthorChia-En Hsiao, Kuang-Yi Lin, Tzu-Kang Lin, Lyan-Ywan Lu
KeywordsGround motion characteristics, Support vector machine, Structural control, Genetic algorithm, Fuzzy control.
AbstractIn recent years, researches on structural control combining earthquake early warning have been widely studied. In the field of seismic engineering, ground motions can be mainly classified into near-fault and far-field ground motions. While the ground motion characteristics have a great influence on control performance; however, the existing earthquake early warning system can only predict the peak ground acceleration, and the optimal control efficiency cannot be promptly achieved. Therefore, a prediction module for ground motion characteristics is proposed in this study. A database of near-fault ground motions and far-field ground motions is first collected, and the six p-wave features and the high-frequency energy accumulations of the ground dynamic spectrum are used to establish the ground motion characteristic prediction module by utilizing support vector machine. In order to develop the intelligent structural control system, the Leverage-type Stiffness Controllable Isolation System (LSCIS) is used as the structural control mechanism. The effective isolation stiffness of the LSCIS can be swiftly changed to control the dynamic response of the structure. The control parameters corresponding to different types of ground motion are optimized by genetic algorithm, and fuzzy control is adopted for the intelligent isolation system.
TitlePiezoelectric Tuned Mass Damper for Vertical Vibration Reduction and Energy Harvesting
AuthorYong-An Lai, Wei-Ling Chou, Lap-Loi Chung
Keywordstuned mass damper, piezoelectric material, energy harvesting, vertical vibration reduction, optimal design
AbstractIn recent years, the energy consumption has continually grown. However, due to climate change, the use of fossil fuel to generate electrical power forces to be reduced. Therefore, looking for environmental friendly energy sources is one of the current research priorities. Because of the development of civil engineering technology, the design and construction of structures turn into more economical. The weight of the bridge structure is becoming lighter, the appearance is accomplishing slender, and the structural period is therefore prolonged, making the bridge structure more susceptible to external forces such as pedestrian loads. In order to effectively reduce the vibration, civil engineers designed and installed Tuned Mass Damper (TMD). Through the tuning of the natural frequency of TMD to the structure, the vibration energy of the structure was absorbed and then dissipated by dashpot. However, this absorbed energy is a kind of green energy source to waste to be dissipated. In view of this, this article studies “Piezoelectric Tuned Mass Damper (Piezo-TMD)”, which uses piezoelectric materials to convert the mechanical vibration energy into electricity for energy harvesting. This research proposes the model and derives the equation of motion of the Piezo-TMD system. Different from the conventional TMD, Piezo-TMD has a circuit equation in addition to the mechanical equation, and these two equations are mutually coupled. The design goal of the Piezo-TMD in this paper is to maximize the average power for energy harvesting, and the numerical simulations are carried out with a pedestrian bridge structure. The simulation results show that the Piezo-TMD achieves the similar performance of vibration reduction as the conventional TMD and thus the vibration comfort requirement can be satisfied. Moreover, the vibration energy is further transferred to electricity for harvest to verify the feasibility of Piezo-TMD. In addition to tuning the mechanical natural frequency of the Piezo-TMD, the natural frequency of the circuit also needs to be tuned to the structure, so that the vibration energy of the structure can be effectively transferred to the circuit by using the resonance effect.
TitleDouble-curvature cyclic test of columns with five-spiral reinforcement and discreet computational shear strength model
AuthorYu-Chen Ou and Jhe-Yan Li
Keywordsshear strength; five-spiral reinforcement; columns; discreet computational shear strength model; cyclic test
AbstractFive-spiral reinforcement has been proved to have superior confinement capability to conventional rectilinear hoops. The objective of this research is to investigate the shear strength of five-spiral reinforcement. Large-scale columns with five-spiral reinforcement and control columns with conventional rectilinear reinforcement were tested in this research using double-curvature cyclic loading. Test results showed that with the same volume of reinforcement and similar reinforcement yield strength and concrete compressive strength, the shear strength of columns with five-spiral reinforcement was slightly less than that with conventional rectilinear reinforcement. However, the strength degradation after the peak strength for columns with five-spiral reinforcement was slower than that for columns with conventional rectilinear reinforcement. Under high axial load, the failure mode of columns with five-spiral reinforcement was fracture of spirals.In contrast, the failure mode of columns with conventional rectilinear reinforcement was the loosening of hook anchorage of the reinforcement. An improved discreet computational shear strength model is developed in this research and validated by the test results. The model can be conservatively used for estimating the shear strength of five-spiral reinforcement. Moreover, the model shows a conservatism for estimating the shear strength of five-spiral reinforcement similar tothat shown by the code shear strength equations for conventional rectilinear reinforcement.
TitleEffect of sensor deploymentonen on the accuracy of ambient vibration method incorporating mode shape functions for cable tension estimation
AuthorChien-Chou Chen, Wen-Hwa Wu, Shin-Yi Chen and Gwolong Lai
Keywordsambient vibration method, cable tension estimation, mode shape, effective vibration length, multiple synchronous measurements, sensor deployment
AbstractThe complicated boundary conditions resulted from the anchorage systems at both ends usually deteriorate the accuracy of the ambient method for cable tension estimation. Motivated by tackling such a problem, a novel method incorporating the mode shape functions was recently proposed by this research group. More specifically, the fitting for the sinusoidal components of mode shape functions was adopted to determine the effective vibration length for each mode such that the interference from the complicated boundary conditions can be eliminated. The success of this method is most critically decided by the accurate reproduction of the sinusoidal components of mode shape functions based on multiple synchronous measurements. The current paper first explains the basic concepts of this cable tension estimation method with the theoretically derived mode shape functions and frequency equations. The finite element models are further employed to evaluate the accuracy of this method and establish the guidelines for the preferred sensor deployment in measurement points and spacing with the consideration of practical measurement limitations. Finally, the applicability of the developed guidelines and the corresponding accuracy in tension estimation are verified by demonstrative laboratory experiments with a prestressed strand.

2020年鋼筋混凝土與鋼結構設計技術研討會

作者:

親愛的會員  您好

國家地震工程研究中心主辦

2020年鋼筋混凝土與鋼結構設計技術研討會。

時間：民國109年12月17 、  18日(星期四、五)

地點：國家地震工程研究中心一樓R101會議室費用：1,600元整，民國109年12月11日(星期五)前截止報名

名額：預計120人，依報名順序，額滿為止

：即日起開始報名，請上網址：http://conf.ncree.org.tw/indexCht.aspx?n=A10912170

 

中華民國結構工程學會 敬啟-109/11/16

研討會DM1103

國震中心_2020年既有建物耐震能力評估與補強研討會

作者:

親愛的會員  您好，

國家地震工程研究中心主辦「2020年既有建物耐震能力評估與補強」研討會。

時間：民國109年11月27日(星期五)

地點：國家地震工程研究中心一樓R101會議室

費用：500元整，民國109年11月20日(星期五)前截止報名

名額：預計135人，依報名順序，額滿為止

報名方式：即日起開始報名，請上網址：https://conf.ncree.org.tw/index.aspx?n=A10911270

中華民國結構工程學會敬啟-109/10/26

 

以上資訊詳如附件：研討會DM1103

2020 年既有建物耐震能力評估與補強.pdf

代轉發臺灣大學應用力學所教師徵聘啟事

作者:

親愛的會員，

轉發訊息如下：

檢附臺灣大學應用力學所教師徵聘中英文啟事及教職申請基本資料表（中、英文版）如附檔，請參考．

 

 

應用力學研究所教職申請表 Brief Application Form for Faculty Position 110學年徵聘教師啟事-英文 110學年徵聘教師啟事-英文 110學年徵聘教師啟事-中文 110學年徵聘教師啟事-中文

中華民國結構工程學會　敬啟

【代轉發】中工會活動訊息

作者:

親愛的會員，

轉發中工會活動訊息如下：

中工會活動特別邀請到遠通電收負責海外業務的吳忠潔副總分享進軍新南向國家的成功模式，以及多位亞太工程師/海外拓點業者與您面對面聊聊海外實戰的甘苦。活動規畫、主講人介紹、議程請參考活動網頁：https://sites.google.com/view/2020apecengineergo/。

◎ 日期：2020年9月29日（二）下午13:00-16:30

◎ 地點：臺北市仁愛路三段160號台北福華大飯店3樓金龍廳

◎ 指導單位：行政院公共工程委員會

◎ 線上報名：https://bit.ly/2ZeS7Mx。

◎ 報名截止日期：2020年9月22日(額滿提前截止)

◎  本次活動免費，限額60人（以亞太工程師、國際工程師優先），額滿即止，恕不接受現場報名。

◎ 全程參與本活動者可獲得工程會技師訓練積分、公務人員終身學習時數；全程參與之亞太及國際工程師可獲得第II類CPD積分3分。

中國工程師學會(CIE) 電話：02- 23925128 學會LINE ID：cie19120101（歡迎加好友） 學會網站：http://www.cie.org.tw/ CIE Podcast: http://www.cie.org.tw/Podcast/PodcastDetail/1

 

中華民國結構工程學會　敬啟

唐獎教育基金會訂於9月21日下午4時舉辦唐獎大師論壇-永續場

作者:

各位先進：

面對21世紀的新挑戰，為追求人類及環境之永續發展，尹衍樑博士於2012年設置唐獎，以獎勵在永續發展、生技醫藥、漢學及法治四個領域，有創新及顯著貢獻之個人或組織。2020年唐獎永續發展獎頒給珍古德博士(Dr. Jane Goodall)，表彰她在靈長類動物研究的開創性發現，足以重新定義人類與動物的關係，以及她終身在地球環境保育工作上無與倫比的奉獻。

唐獎教育基金會同國立清華大學於9月21日(星期一)下午4時-6時舉辦「2020唐獎大師論壇-永續發展場」，主題為「自然生態保育與人類社會之永續發展：由COVID-19談起」，會中珍古德博士(Dr. Jane Goodall)將就新冠肺炎大流行對人類與動物及自然環境之間關係，及人類社會的永續發展給予精闢見解。該場次另邀請三位前唐獎永續發展獎得主，包括：前WHO秘書長格羅．哈萊姆．布倫特蘭(Dr. Gro Harlem Brundtland)、哥倫比亞大學地球學院氣候科學、覺知與解決方案主任詹姆士．漢森(Dr. James Hansen)、加州大學聖地牙哥分校應用海洋科學Victor C. Alderson講座教授維拉布哈德蘭•拉馬納森(Prof. Veerabhadran Ramanathan)參與，期盼透過該論壇探討受疫情影響導致社會、經濟不平等相關議題，及達成生態保育及永續未來之策略。

本活動主要採線上直播(live stream)與世界各地互動，議程請詳如附件，歡迎各位踴躍於9月21下午至唐獎官網(https://www.tang-prize.org/week.php?cat=139)參與線上直播論壇，並請轉知有興趣朋友共同分享，本論壇直播內容亦可於活動後觀看。

 

自然生態保育與人類社會之永續發展：由COVID-19談起

經濟發展、環境保護以及社會公義為永續發展的三大支柱，而生態保育為環境保護的核心內容之一。在新冠肺炎（COVID-19）大流行影響人類期間，除暴露全球社會經濟不平等之問題，也提醒世人應以推行永續發展為首要工作。本屆唐獎永續發展獎得主珍古德博士在靈長類動物硏究有開創性發現，並致力環境教育及生物多樣性保育，對地球環境保育有無與倫比的貢獻。珍古德博士讓世人瞭解到人類、動物及環境之間密不可分的關係，在面對疫情持續挑戰之際，得透過本論壇意見交流，共同探討生態保育及達成永續未來之道等重要議題。

因全球疫情影響，本場論壇不開放校外報名，採視訊及中英文全程直播

直播資訊:  https://www.tang-prize.org/week.php?cat=139

 

台灣時間：2020年9月21日 (一) 16:00-18:00 世界時間轉換

地  點：國立清華大學 旺宏館 國際會議廳

主辦單位：唐獎教育基金會   國立清華大學

議程:

16:00-16:05 開幕致詞
16:05-16:10 介紹珍古德博士
16:10-16:30 第四屆唐獎得主 珍古德博士 演講
16:30-17:55 歷屆得主談話、與談人綜合討論、Q&A
17:55-18:00 結語

主持人
  • 廖俊智
  • 中央研究院院長
  • 美國國家工程學院院士
  • 美國國家科學院院士
與談人
  • 蘇慧貞
  • 國立成功大學校長
  • 國立成功大學工業衛生學科暨環境醫學研究所特聘教授
  • 李家維
  • 國立清華大學生命科學系教授
  • 台灣《科學人》雜誌總編輯
特別來賓 / 唐獎歷屆得主
  • 格羅・哈萊姆・布倫特蘭
  • 2014唐獎永續發展獎得主
  • 挪威前總理
  • WHO前秘書長
  • 詹姆士・漢森
  • 2018唐獎永續發展獎得主
  • 哥倫比亞大學地球學院氣候科學、
  • 覺知與解決方案主任
  • 維拉布哈德蘭・拉馬納森
  • 2018唐獎永續發展獎得主
  • 加州大學聖地牙哥分校應用海洋科學
  • Victor C. Alderson講座教授
  • 加州大學聖地牙哥分校斯克里普斯海洋研究所雲氣、化學與氣候中心主任

 

第三十五卷第二期 (期別136) (109年)

作者:

第三十五卷第二期(期別136)(109年)

標題混凝土潛變及自體收縮對鋼管混凝土柱之影響研究及設計建議
作者游雅如、陳振川、廖文正
關鍵字鋼管混凝土、潛變、自體收縮、應力轉移、B4-TW潛變收縮模式
摘要鋼管混凝土柱(Concrete-filled steel tubular column，簡稱CFT柱)具高強度、高韌性，被視為具有良好耐震性能的結構構件。早期鋼管內灌混凝土是為了增加構件的側向勁度，並延緩挫曲行為的發生。近年工程師開始將核心混凝土納入實際承重單元。CFT柱受力後，混凝土潛變就會隨時間持續發展，而柱構件為了保持其斷面力平衡，混凝土會將承擔的部分軸力移轉至鋼管，這些移轉量可能會使鋼管降伏，影響結構物的安全。此外，低水膠比的高強度自充填混凝土，也會產生大量自體收縮，使構件內混凝土及鋼管間應力移轉現象愈嚴重。本研究以有限元素分析軟體ABAQUS建置三維鋼管混凝土柱模型，選擇可反映台灣混凝土特性之B4-TW潛變收縮模式，研究混凝土潛變及自體收縮引致之構件內部應力移轉的情形。模擬結果顯示，在初始鋼骨應力設定為0.6f_y的情況下，無論荷載是否偏心，考慮混凝土潛變收縮效應的最終鋼應力皆有機會超出「鋼構造建築物鋼結構設計技術規範」檢核標準。而且在使用高強度自充填混凝土及構件高寬厚比的極端情況下，鋼應力可上升0.33f_y，將大幅超過原始設計值。未來設計應注重長期荷載效應，並考量混凝土長期變形對於鋼管應力的影響。
TitleStudy of the Influence of Creep and Shrinkage on Concrete-Filled Steel Tubular Columns and Design Suggestions
AuthorYa-Ju Yu, Jenn-ChuanChern, Wen-Cheng Liao
KeywordsCFT, creep, autogenous shrinkage, stress transfer,B4-TW creep and shrinkage prediction model
AbstractConcrete-filled steel tubular (CFT) columns show not only high strength and high ductility but also exhibit favorable seismic performance. The primary intent of concrete infill is to increase lateral stiffness of member and delay the local buckling of the steel tubular. Once concrete is subjected to load, development of concrete creep begins. In order to maintain the equilibrium of forces of CFT section, part of axial load of concrete will be transferred to steel tubular which leads to the growth of steel stress. Furthermore, high strength self-consolidating concrete (SCC) with low water-to-cement ratio intensifies the rise of steel stress in CFT columns on account of high autogenous shrinkage.A three-dimensional finite element model of CFT column, which takes account of the phenomenon of concrete creep and shrinkage, is developed to evaluate stress transfer between concrete and steel in ABAQUS. B4-TWcreep and shrinkage prediction model is also applied to reflect a characteristic of high amount of paste in concrete mix designs in Taiwan owing to the soft nature of coarse aggregates. The analysis results show that under the condition of initial steel stress of 0.6݂௬, the final steel stress of CFT column is probably not qualified according to “Design and Technique Specifications of Steel Structures for Buildings” owing to the long term deformation of infilled concrete whether the load is eccentric or not. In the extreme case of high concrete compressive strength of SCC and high diameter to thickness ratio, the steel stress significantly exceeds the original design value with 0.33݂௬. It is suggested that relevant specifications should be revised accordingly in Taiwan.
標題考慮鋼筋腐蝕影響之RC建築物耐震能力初步評估法
作者邱建國、詹宗翰、蔡宜靜
關鍵字初步耐震能力評估、目視調查、劣化度、鋼筋腐蝕
摘要本研究參考過去計劃成果以建立鋼筋腐蝕構件之力學評估模型，對腐蝕構件之塑鉸容量進行折減，除進行相關試驗資料之比對與驗證外，根據文獻所收集一般典型校舍及街屋的常用構件尺寸及斷面配筋，計算柱構件於不同劣化程度下之強度折減係數，提供評估人員搭配既有之初步耐震能力評估法使用。換言之，評估人員可參考RC建築物耐久性能診斷技術手冊之建議，依目視調查構件外觀之劣損以判定其劣化程度，並參考本文建議之折減係數修正其強度。本文最後以一既有校舍為範例，考量構件於不同劣化程度下之耐震能力，以國震中心所建立之TEASPA搭配結構分析軟體ETABS進行詳細評估，並與本研究所提供之初步耐震能力評估進行比對，以了解其合適性。
TitlePreliminary Seismic Performance Evaluation Method of RC Buildings Considering the Corrosion Effect of Reinforcement
AuthorChien-Kuo Chiu, Zong-Han Jhan, Yi-Jing Cai
KeywordsPreliminary seismic performance evaluation, Visual inspevtion, Deterioration de gree, Corroded reinforcement
AbstractThis research establishes a mechanical evaluation model of a corroded RC member and reduces its plastic hinge capacity on the basis of the past research project. In addition to do the comparison and verification with the relevant experiment data, this research collects the general information of the size of column members and reinforcement arrangement in a typical reinforced concrete building and street house for investigation on the reduction factor of strength. Restated, the reduction factor of strength can be used to consider effect of the deterioration or corrosion in the strength or seismic capacity for a corroded RC column member. Therefore, this work can provide a preliminary seismic performance evaluation method for a corroded RC building structure. Additionally, for a corroded column member, its reduction factor of strength is determined based on the deterioration degree, which can be judged based on the visual inspection of deterioration following the technical textbook of the durability assessment of deteriorating RC building structures. Finally, taking an existing school building for an example, TEASPA which is established by NCREE is used to evaluate the seismic performance considering the corrosion and verify the application of the proposed preliminary seismic performance evaluation method for a corroded RC building structure.
標題以2018花蓮地震震害建物探討耐震初評方法之有效性
作者杜怡萱、葉桐
關鍵字震害，耐震評估，初步評估，鋼筋混凝土
摘要本研究蒐集2018年0206花蓮地震中12棟不同震害程度之建物資料，應用於三種國內現行耐震初步評估方法，以探討其有效性及合理性。三種耐震初評方法包括：鋼筋混凝土建築物耐震能力初步評估（PSERCB）、國家地震工程研究中心（NCREE）校舍耐震初評及街屋耐震快評；評估結果顯示，三種初評方法皆能大略篩選出耐震能力有疑慮之建物，各初評方法之評估結果與震害等級之相對關係亦大致符合，但皆呈現較保守之趨勢。各建物之三種初評結果大多相近，僅有二棟建物之NCREE街屋快評結果與另外兩種方法出現差異，且皆顯示PSERCB及NCREE校舍初評較NCREE街屋快評更為保守。
TitleVerification of Preliminary Seismic Evaluation Methods Using the Damaged Building Data of  2018 Hualien Earthquake
AuthorYi-Hsuan Tu and Tung Yeh
Keywordsearthquake damage, seismic evaluation, preliminary evaluation, reinforced concrete
AbstractData of thirteen buildings that damaged differently in the 2018 Hualien earthquake were collected and used to verify three preliminary seismic assessment methods. The three methods are all widely used in Taiwan, including the Preliminary Seismic Evalureliminary seismic evaluation of RC Buildings (PSERCB), the Preliminary Seismic Evaluation Method for Typical Building Structures of Primary and Secondary Schools by NCREE, and the Preliminary Seismic Evaluation Method for Typical Street-houses by NCREE. Comparison between the evaluation results and the observed damage states of the thirteen buildings showed that all three methods can identify the buildings that were heavily damaged. All three methods can sort the buildings in an approximately reasonable order. However, all three methods tended to give conservative results. The results from different methods for the same building were usually close. Only two buildings obtained different results between the NCREE method for street-houses and the other two methods. The PSERCB and the NCREE method for school buildings showed more conservative results than the NCREE method for street-houses in the two buildings.
標題具多重耐震性能等級之機率式結構耐震評估法
作者盧煉元、蕭輔沛、湯宇仕、黃尹男、陳慶輝、李官峰
關鍵字耐震評估、機率式評估法、多重性能等級、隔震結構、性能設計法、增量動力分析、非線性動力分析、非線性塑鉸
摘要現有耐震評估法大多僅能用於評估建物之抗倒塌耐震能力，因其損傷準則係依據結構瀕臨倒塌之行為為主。此種耐震評估法並不適用於評估重要之功能性建物(例如：醫院、高科技廠)或隔震結構，因為此類建物係以強震中必須保有其功能性為其耐震目標之一。有鑑於此，本文乃針對具高度耐震性能要求之重要建物與隔震結構研議一套可考量多種性能目標之機率式耐震評估法及流程，此法乃參採FEMA356與ASCE 41-13之建議將建物之耐震性能等級分為：立即可用(IO)、生命安全(LS)、倒塌避免(CP)。各性能等級之損傷準則分為整體損傷準則與局部損傷準則，前者採用FEMA 356及PEER-TBI之標準；而後者則參採ASCE41-13所建議之構件損傷準則。根據這些損傷準則與增量動力分析之結果，再據以建立不同性能等級之易損曲線作為耐震評估之依據。若為隔震結構，則新增隔震極限(IL)之性能等級，以便將隔震層之安全性納入耐震評估中，其損傷準則係以隔震支承位移超過隔震設計規範所訂定之最大總位移 為依據。本文以一幢耐震力不足之老舊建物為例，並採用滑動隔震技術對該建物進行耐震補強，再以所建議之多重性能耐震評估法，對隔震補強前後結構之耐震性能進行評估與比較，以量化隔震補強對於不同耐震性能等級之效益。評估結果顯示，原先倒塌風險極高之原始建物，經過隔震補強後，各性能等級之損傷機率指標皆明顯下降。因此，本文提出之機率式耐震評估法適用於隔震或固定基礎結構，可供工程界完整評估建物於不同耐震性能等級中之風險。
TitleAn approach for probabilistic seismic performance assessment of buildings considering multiple performance levels
AuthorLyan-Ywan Lu, Fu-Pei Hsiao,Yu-Shi Tang,Yin-Nan Huang,Ching-Huei Chen, Kuan Feng Lee
Keywordsseismic performance assessment, probabilistic assessment, multiple performance levels, isolated building, performance design, incremental dynamic analysis, nonlinear time history analysis, plastic hinge
Abstract Most of current seismic assessment methods for buildings aim to evaluate the collapse risk of buildings, since the damage criteria of these methods are associated with the mechanism of building collapse. These methods may not be suitable for the assessment of functional facilities or seismic isolated buildings, whose performance objective is usually required to maintain their functionality after a strong earthquake. For this reason, this study proposes an approachfor probabilistic seismic assessment of buildings considering multiple performance levels. This approach adopts the performance levels defined by FEMA 356 and ASCE 41-13, namely, immediate occupancy (IO), life safety (LS) and collapse prevention (CP). For each performance level, both global and local damage criteria are defined according to FEMA 356 and ASCE 41-13, respectively. Based on these damage criteria together with the result of incremental dynamic analysis, the fragility curves for each performance level can be established for seismic assessment. For buildings with isolators, a performance level called isolation limit (IL) is also considered, in order to include safety of the isolation system in the assessment procedure. The damage criterion for IL performance level is defined as when the isolator drift exceeds the maximum total isolator displacement   given in the current isolation design code of Taiwan. For demonstration of the proposed assessment method, a 5-story old apartment building was consideredas an example. The building was retrofitted by using sliding isolators, and the seismic performance of the building before and after the implementation of isolation was evaluated using the proposed method and the results were compared, so that the benefit of retrofitting can be quantified. Theassessment results show that the retrofit with the isolators greatly reduces the damage probabilities of the building at all performance levels. This demonstrates that the proposed method can be applied to evaluate seismic performance of either fixed-based or isolated building with consideration of multiple performance levels.
標題醫院消防撒水系統耐震性能補強評估
作者蔡詠安、林凡茹、柴駿甫、張國鎮
關鍵字消防撒水系統、易損性分析、數值分析、簡化評估、耐震補強
摘要

建築結構之耐震性能在長年的研究，相較早期之建築物已有明顯的提升，在受震後的主要災害與經濟損失往往不是建築結構造成，而是非結構系統之破壞造成。醫院內非結構設備中的消防撒水系統受中小地震後，若發生天花板遭撒水頭碰撞發生擴孔、粉塵掉落，或於大震中，撒水系統之支撐破壞，失去支承能力，可能造成醫院中斷醫療機能，甚至發生淹水、火災等自發性災害。因此消防撒水系統需以性能設計法進行耐震評估，若耐震容量不足則須加裝補強裝置。

本研究以台大雲林分院為案例醫院，依據甲仙地震後的破壞機制，提出消防撒水系統耐震詳細評估法以及適合業界應用之簡化評估流程，並參考NFPA13(National Fire Protection Association, 2010)補強之建議，提出四種補強方案，依據各方案之消防管線系統耐震性能表現建立易損性曲線，探討不同地震歷時之分析結果與適用性，並比較各方案之差異，以期做為消防管線系統耐震設計或補強之參考。

 
TitleSeismic evaluation and strengthening methods for fire protection sprinkler piping systems in hospitals
AuthorYung-An Tsai, Fan-Ru Lin, Juin-Fu Chai, Kuo-Chun Chang
KeywordsFire protection sprinkler system, fragility curve, numerical analysis, simplified assessment, seismic strengthening design
Abstract

In recent years, due to the vigorous development of performance design concepts, the seismic capacity of critical building structures (such as hospitals and high-tech factories) has been improved, and the major disasters and economic losses caused by the earthquake have changed from structural to non-structural systems, which include piping systems.

This study takes the medium-scale hospital in Southern Taiwan as an example to discuss the effects of installing strengthened elements on sprinkler piping systems which recommended by NFPA13. First, this research uses detailed analysis results to construct the fragility curves, and compares the fragility curves between before- and after-strengthened systems. Second, according to the dynamic characteristics of the sprinkler piping system, the simplified assessment method of original system and strengthened system are proposed in this study. It provides engineers with an alternative, rapid and approximate judgment in the seismic performances of piping systems based on in-situ observations and generic floor response spectrum.