第四十卷第二期 (期別156) (114年)
| 標題 | 建築混凝土中性化深度與齡期關係之統計研究 |
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| 作者 | 許嘉芩、廖文義、蕭輔沛 |
| 關鍵字 | 混凝土、中性化、齡期、抗壓強度、耐久性 |
| 摘要 | 混凝土中性化為造成鋼筋混凝土 (reinforced concrete, RC) 結構物老劣化及縮短其使用年限的主因之一，混凝土中性化將導致鋼筋保護膜失去功能，進而造成鋼筋腐蝕、結構承載力降低等問題。因此，預估混凝土中性化深度是評估RC結構物耐久性的重要研究課題。本研究共收集了國內北、中、南、東四區454間學校，1,055棟RC校舍結構物的12,527筆鑽心試體檢測資料，利用相關的中性化深度預估公式，本研究將結構物材料試驗資料進行迴歸分析，以混凝土中性化深度、地域、混凝土齡期與混凝土抗壓強度為參數，進行迴歸分析，找出適用於台灣本土環境和混凝土材料的耐久性評估模式，得到對應之中性化深度與混凝土齡期等時變特性公式。本研究所推估混凝土中性化深度曲線，可以用來評估既有RC房屋結構之中性化深度，進而得知中性化深度是否影響結構物耐久性，並實施適當的維護管理或修復補強措施。 |
| Title | Statistical Study on the Relationship Between the Depth of Neutralization and the Age of Concrete in RC Buildings |
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| Author | Chia-Chin Hsu, Wen-I Liao, Fu-Pei Hsiao |
| Keywords | concrete, neutralization depth, age, compressive strength, durability |
| Abstract | Neutralization of concrete is one of the main factors causing the aging of reinforced concrete (RC) structures and shortening their service life. Neutralization of concrete leads to the loss of functionality of the protective film on the reinforcement, which in turn causes corrosion of the reinforcement and a decrease in structural bearing capacity. Therefore, estimating the depth of concrete neutralization is an important research topic for the durability assessment of reinforced concrete structures. In this study, the material testing data by core sampling from 454 Taiwan RC school buildings were collected. By using relevant formulas used in Japan and Taiwan for predicting neutralization depth, regression analysis was carried out on the material test data base on those formula. Parameters such as concrete neutralization depth, region, concrete age, and concrete compressive strength were used to regressively analyze and derive a durability assessment model suitable for Taiwan’s environment and characteristics of concrete material. Corresponding formulas for neutralization depth and time-variable properties such as building age were obtained. The estimated concrete neutralization depth curve from this study can be used to evaluate the neutralization depth of RC structures during their service life, thereby determining whether neutralization depth affects the durability of the structures, and executing appropriate maintenance or repair and retrofit measure. |
| 標題 | 基於牽引力的深度能量法 (tDEM) 求解彈性體問題初探 |
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| 作者 | 林冠中、王泓量、王國洲 |
| 關鍵字 | 深度學習、PINNs、DEM、tDEM、工程運用、精確性 |
| 摘要 | 隨著深度學習技術在解決複雜物理問題及工程應用領域的飛速進展，物理資訊神經網絡 (physics-informed neural networks, PINNs) 與深度能量法 (deep energy methods, DEM) 這兩種融合物理知識的深度學習策略，已成為科學計算與工程學科研究的新熱點。PINNs透過將物理定律整合至神經網絡訓練過程中，賦予模型在數據稀缺的條件下仍能進行高效且精確的預測能力。而DEM則採用深度學習框架來構築系統能量模型，有效模擬材料變形、破裂等複雜物理過程。儘管PINNs和DEM在模擬複雜物理系統上取得顯著成就，但在模型訓練的計算成本、泛化能力提升等方面仍面臨挑戰。本研究引入了一種新的基於牽引力的深度能量法 (tractionbased deep energy method, tDEM)，該方法考慮到牽引力的邊界效應，是從混合深度能量法 (mixed deep energy method, mDEM) 演化而來，並融合了PINNs與 DEM的優點。相較於mDEM，在訓練過程中引入了本構行為，造成較高的計算成本，tDEM專注於牽引力邊界條件，以期降低計算負擔。未來研究將深入探討這些問題，以提升模型精度與應用廣度。本文不僅回顧了PINNs與DEM的最新進展與工程應用實例，同時提出改進方案，討論了面臨的主要挑戰與未來發展趨勢，目的在於為相關領域研究人員提供有價值的參考，並推動深度學習於物理問題解決方案中的創新應用。 |
| Title | A Preliminary Exploration of the Traction-Based Deep Energy Method (tDEM) for Solving Elastic Body Problems |
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| Author | Kuan-Chung Lin, Hung-Liang Wang, Kuo-Chou Wang |
| Keywords | deep learning, PINNs, DEM, tDEM, engineering applications, accuracy |
| Abstract | With the rapid advancement of deep learning technologies in addressing complex physical problems and engineering applications, physics-informed neural networks (PINNs) and deep energy method (DEM), as two primary deep learning approaches integrating physical knowledge, have emerged as hot topics in computational science and engineering research. PINNs enable efficient and accurate predictions under data-scarce conditions by embedding physical laws into the neural network training regimen. In contrast, DEM utilize deep learning frameworks to establish energy models of systems, adept at simulating complex physical processes such as material deformation and fracture. Despite the significant strides made by PINNs and DEM in simulating complex physical systems, challenges remain in the computational costs of model training and enhancing model generalizability. This study introduces a novel traction-based deep energy method (tDEM), considering the boundary effects of tractions, evolved from the mixed DEM (mDEM) and amalgamating the strengths of both PINNs and DEM. Whereas mDEM introduced constitutive behavior during training, incurring higher computational expenses, tDEM concentrates on traction boundary conditions, aiming to reduce computational overhead. Future research will delve into these issues to further augment model precision and application scope. This paper not only reviews the latest advancements and engineering applications of PINNs and DEM but also proposes improvements, discusses the main challenges faced, and envisages future directions. It aims to provide valuable insights for researchers in the field and to propel the innovative application of deep learning in solving physical problems. |
| 標題 | 蓋板加勁剪力降伏型耐震間柱耐震試驗與設計研究 |
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| 作者 | 許舜惟、蔡克銓、吳安傑 |
| 關鍵字 | 剪力降伏型耐震間柱（鋼板阻尼器）、容量設計、加勁板、蓋板、有限元素模型分析 |
| 摘要 | 三段式剪力降伏型耐震間柱 (steel panel damper, SPD) 又稱三段式鋼板阻尼器，為降低製造成本，本研究不採焊接組合斷面來製作SPD，而是使用熱軋型鋼製造並考慮容量設計法研發蓋板加勁剪力降伏型耐震間柱 (cover-plate stiffened steel panel damper, CSPD)，將特定熱軋型鋼經裁切取得適當尺寸的腹板疊合板及翼板蓋板，將其分別焊接在熱軋型鋼腹板及其翼板外側上下兩端，可提升彈性連接段的勁度及剪力容量，也避免CSPD上下端產生彎矩降伏。以斷面深度為800 mm、高為2,600 mm、相同設計剪力及相似側向勁度（相差3%）的情況下，CSPD僅需SPD的87%用鋼量。為驗證核心段加勁板設計方法是否能有效應用於SN490B，本研究特別採SN490B熱軋型鋼RH800 × 300 × 14 × 26製造兩座2.60 m高試體。實驗結果證實，彈性連接段翼板蓋板能有效避免CSPD端部產生彎矩降伏；彈性連接段腹部疊合板能避免彈性連接段產生剪力降伏。本研究證實所提設計方法能有效預估核心段及整體CSPD變形能力、側向勁度與極限強度。有限元素模型能準確模擬CSPD的強度、勁度及遲滯行為。本研究列出在常見的CSPD高度及層間位移需求下之CSPD完整設計結果，工程師能透過查表得到CSPD所有設計細節。 |
| Title | Seismic Design, Testing and Analysis of CoverPlate Stiffened Steel Panel Damper |
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| Author | Shun-Wei Hsu, Keh-Chyuan Tsai, An-Chien Wu |
| Keywords | steel panel damper, capacity design, stiffener, cover plate, finite element model analysis |
| Abstract | The three-segment steel shear panel damper (SPD) consists of an inelastic core (IC) that controls overall strength and could dissipate energy through large inelastic shear deformation. The two elastic joints (EJs) at the both ends of the SPD that remain elastic and provide lateral stiffness. Stiffeners are welded to the IC web to delay the shear buckling. This study employs hot-rolled, as opposed to built-up, sections to fabricate the SPD. This study proposes a cover-plate stiffened steel panel damper (CSPD). It involves cutting specific hot-rolled steel beam to obtain the doubler plates and cover plates, which are welded respectively to the web and the outer surfaces of the f lange at the both ends of the same hot-rolled steel beam. For example, with a section depth of 800mm, height of 2600mm, the same design shear force, and similar lateral stiffness, the proposed CSPD weighs only 87% of the conventional 3-segment SPD. This study intentionally uses SN490B steel for specimens to validate the design procedures for stiffeners in the IC. Test results, of two 2.60 m tall full-scale CSPD specimens using RH800 × 300 × 14 × 26 section with different IC height and stiffeners, confirm that the cover plates and doubler plates work as expected. This study confirms that the proposed CSPD design procedures can effectively estimate the IC shear deformational capacity, lateral stiffness and maximum shear strength of the CSPD. The proposed finite element model can accurately simulate the strength, stiffness, and hysteretic behavior of the CSPDs. This study tabulates the complete design results for CSPDs using American Institute of Steel Construction (AISC) sections with typical heights and inter-story drift demands. Results of additional finite element model parametric studies confirm that different IC stiffener arrangements can achieve the targeted shear deformational capacities as predicted using the proposed design procedure. |
| 標題 | 圓形鋼管橋墩之耐震徑厚比與破壞風險分析 |
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| 作者 | 蕭玟鈺、吳東諭、江奇融、歐昱辰 |
| 關鍵字 | 單柱式鋼橋墩、徑厚比限制、有限元素分析、韌性容量、破壞風險分析、近斷層地震 |
| 摘要 | 橋墩為橋梁之韌性構件，當橋梁遭逢極端地震時，可藉塑鉸消能降低橋梁整體結構之損壞。因此，使其展現足夠強度對於橋梁之耐震設計極為重要。我國相關耐震規範中對鋼橋墩設計著墨甚少，使實務設計上無明確可遵循之依據，僅能參考他國耐震設計流程進行設計，惟各國耐震設計規範之精神及性能要求不盡相同，應進一步檢討後方可採用。此外，過往鋼橋墩之相關研究多以斷面性質、加載方式等因素探討其非線性行為，然對於真實地震下之鋼橋墩，地震強度與其引致之結構反應均具不確定性，需利用機率式分析，完整評估鋼橋墩之震災風險及耐震能力。有鑑於此，本研究以圓形空心斷面單柱式鋼橋墩為研究對象，探討不同徑厚比、長細比、軸壓比等關鍵參數對韌性容量及破壞風險之影響。首先以擬靜態分析求取鋼橋墩之韌性容量，以此定義後續非線性歷時分析之破壞基準，並提出斷面性質之建議公式。而鋼橋墩之破壞行為分兩部分進行討論，其一，假設鋼橋墩工址位於台北二區，分析圓形單柱式鋼橋墩之50年破壞風險；其二，假設台北山腳斷層之地震情境，計算符合該情境之近斷層地震歷時下破壞機率。最後，依據破壞行為分析之結果，檢視建議公式之適宜性，對圓形斷面單柱式鋼橋墩之斷面性質提出耐震設計建議。 |
| Title | Seismic Compactness and Risk Assessments of Circular Steel Bridge Piers |
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| Author | Wen-Yu Xiao, Tung-Yu Wu, Chi-Rung Jiang, Yu-Chen Ou |
| Keywords | single-column steel bridge piers, compactness requirements, finite element analysis, ductility capacity, risk analysis, near-fault ground motions |
| Abstract | Bridge piers, which are ductile components of bridges, need to exhibit sufficient energy dissipation under earthquakes. However, there is little emphasis on the compactness requirements for steel bridge piers in Taiwan seismic design codes. Structural engineers can only refer to seismic design guidelines from other countries, but the difference in the seismic design concept makes them potentially inappropriate for Taiwan. To address this shortcoming, this study investigates single-column steel bridge piers with varied compactness and axial load levels. The ductility capacity of each pier is determined by quasi-static analysis and considered as the failure criteria in the subsequent risk assessment. Assuming located in the Taipei basin zone II, the seismic risk of steel bridge piers is evaluated using the failure probability during the 50-year lifespan and under the seismic scenario of the Shanchiao fault. Based on the results of ductility capacity and risk assessment, the seismic compactness requirements are proposed for single-column steel bridge piers. |
| 標題 | 挫屈束制斜撐平板狀核心鋼板高模態外推力之評估與試驗驗證 |
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| 作者 | 張致唯、林保均、巫秉澄 |
| 關鍵字 | 挫屈束制斜撐、局部膨脹破壞、高模態挫屈、反覆載重試驗、全鋼圍束單元 |
| 摘要 | 採用平板狀鋼核心挫屈束制斜撐 (buckling-restrained brace, BRB) 受壓時，核心鋼板在脫層間隙空間內產生高模態挫屈波，若圍束單元未提供足夠的束制強度與勁度，高模態挫屈波峰產生的外推力可能造成局部膨脹破壞。過去對於高模態挫屈波長以及外推力的評估研究較少，且無實驗驗證結果，因此本研究透過5組採用全鋼圍束單元之BRB試體，進行反覆載重試驗，並透過試驗觀測高模態挫屈波長並直接量測其所引致之外推力。本研究包含3組短試體與2組長試體，短試體核心長度為300 mm並分別調整核心與圍束單元間隙至0.6 mm、2 mm以及4 mm；長試體核心長度為900 mm，核心與圍束單元間隙為2 mm。試驗結果顯示，5組試體皆發展穩定之遲滯行為至核心拉斷裂。高模態挫屈外推力由荷重計直接量測，同時在核心板厚度方向部設應變計以量測應變與波型的關係。試驗結果顯示，使用切線模數理論可以較為準確計算高模態挫屈波長。此外，外推力以及核心與圍束單元間隙的正相關連也透過實驗驗證。透過試驗結果，本研究所提出之外推力評估方法，同時考量核心高模態挫屈波峰彎矩以及圍束單元勁度，此評估方法可作為檢核BRB發生局部膨脹破壞風險之用。 |
| Title | Experimental Study of High-Mode Buckling Behavior of Flat Steel Core in a Buckling-Restrained Brace |
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| Author | Chih-Wei Chang, Pao-Chun Lin, Bing-Cheng Wu |
| Keywords | buckling-restrained brace, local bulging failure, high-mode buckling, cyclic loading test, all-steel restrainer |
| Abstract | Buckling-restrained braces (BRBs) featuring flat steel core plates can be susceptible to local bulging failures when the restrainer lacks the necessary stiffness and strength. These failures arise from outward forces generated by high-mode buckling waves within the steel core. However, the methods for evaluating these high-mode buckling waves and the associated outward forces have remained elusive. This study addresses this gap by conducting cyclic loading tests on five BRB specimens with all-steel restrainers. These tests allow for direct observation of high-mode buckling waves during loading. Among the specimens, three have core segment lengths of 300 mm, each with varying debonding layer thicknesses (0.6 mm, 2 mm, and 4 mm). The remaining two specimens have approximately 900 mm core segments with a 2 mm thick debonding layer. All f ive specimens displayed stable hysteretic responses until the steel core fractured. Load cells were used to directly measure the outward forces induced by the steel core plate during testing. Strain gauges attached to the steel core surface provided insights into the distribution of strain variations at the high-mode buckling waves. The results indicate that adopting the tangent modulus theorem is a suitable method for estimating high-mode buckling wavelengths. Furthermore, this study establishes relationships between the outward forces and gap dimensions, including their growth over time. This research proposes a method to estimate outward forces, accounting for bending moments developed at the crests of high-mode buckling waves and considering restrainer stiffness. This method can serve as a valuable tool for assessing the risk of local bulging failure in BRBs. |
