鋼筋混凝土梁受彎矩及扭矩作用下之行為研究

Behavior of Reinforced Concrete Beams Subjected to Torsion and Bending

吳嘉偉(Chia-Wei Wu)

指導教授 ： 何仲明

中原大學/工學院/土木工程研究所/碩士(2001年)

https://doi.org/10.6840/cycu200100066

摘要

摘 要

本文旨在研究鋼筋混凝土梁承受彎矩與扭矩作用下之抗扭行為。主要目的在於探討鋼筋混凝土梁，在不同扭力箍筋數量，承受不同載重組合下的極限扭矩及開裂扭矩，並藉由試驗數據評估ACI 318-95及ACI 318-89規範中扭力預測式之適用性。本研究以箍筋數量、縱向筋和不同彎矩與扭矩載重組合為考慮變數，共規劃12支鋼筋混凝土梁試體進行加載試驗。
試驗結果顯示，每支試體梁之開裂後扭轉勁度相較於開裂之前均有明顯減少之現象，且箍筋數量愈多之試體梁，開裂之後能維持較高勁度。對於ACI 318-95及ACI 318-89規範的極限扭矩在載重組合的適用性，明顯的ACI 318-95比ACI 318-89來的好，而且扭矩預測式於在本研究彎矩與扭矩組合載重下適用情形良好。

關鍵字

鋼筋混凝土梁 ； 極限扭矩 ； 扭轉角.

並列摘要

Abstract

The aim of this research is to study the behavior of reinforced beams subjected to the combined effect of bending and torsion. The focus is on the ultimate strength of reinforced beams with different amount of stirrups and different ratios of bending and torsion. Tests are carried out to verify the design methods proposed by ACI 318-95 and ACI 318-89. The variables included in the tests are: amount of stirrups, amount of longitudinal reinforcements and bending to torsion ratio. A total of 12 beams are tests.
Test result shows that the torsional stiffness of the beam is reduced after it is cracked. A higher torsional stiffness can be obtained by providing more stirrups. The method proposed by ACI 318-95 to predict the ultimate strength of the beam is more accurate than that of ACI 318-89 as shown by the tests carried out is this research.

並列關鍵字

reinforced concrete beam ； twist angle. ； ultimate torsion

參考文獻

1. Hsu, T. T. C., and Mo, Y. L., “Softening of Concrete in Torsional Members_Theory and Tests,” ACI Journal, V.82, No. 3, May-June 1985, pp.290-303.

2. Hsu, T. T. C., “Shear Flow Zone in Torsion of Reinforced Concrete,” Journal of Structural Engineering, ASCE, V.116, No. 11, 1990, pp.3206-3226.

3. Chen, W.H., and, M.Y., “ Torsional Behavior of High Strength Concrete Beams,” National Sci. Counc. ROC (A), V.19, No.3, 1995, pp.235-244.

5. ACI Committee 318, “Building Code Requirements for Reinforced Concrete (ACI 318-71),” American Concrete Institute, Detroit, 1971, pp.78.

6. Collins, M.P., and Mitchell, D., “Shear and Torsion Design of Prestressed and Non-Prestressed Concrete Beams,” PCI Journal, V.25, No.5, Sept.-Oct. 1980,pp.32-100 .