| Title: | COMPLETE NONLINEAR BEHAVIOUR OF NORMAL- AND HIGH-STRENGTH CONCRETE BEAMS UNDER CYCLIC LOADING |
| DOI No: | 10.1142/9789812701480_0093 |
| Source: | TALL BUILDINGS (pp 615-621)
|
| Author(s): | BILL Z. Z. BAI
Department of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, China
FRANCIS T. K. AU
Department of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, China
|
| Abstract: | Even in a structure that is loaded monotonically, some parts of it may experience curvature reversal, not to mention the much more complex loading history imposed by earthquakes. Therefore to get a reliable estimate of the safety of a structure under earthquake loading, it is worthwhile to carry out full-range analysis under cyclic loading. In this paper, the complete nonlinear behaviour of reinforced concrete beams made of normal- and high-strength concrete under cyclic loading is studied using a numerical method that employs the actual stress-strain curves of the constitutive materials and takes into account the stress-path dependence of the concrete and steel reinforcement. The loading history considered includes loading, and repetitive cycles of unloading and reloading. In particular, loading past the peak strength into the post-peak stage is investigated. It is found that the complete moment-curvature relationship, which is path-dependent, is similar to the material stress-strain relationship with stress-path dependence. Degradation of section stiffness is observed as the cyclic loading extends to large curvatures, especially at the post-peak stage. Upon reloading, it may not follow the original unloading path, but the difference between the two paths is not significant for the cases studied. Different aspects of behaviour between under- and over-reinforced sections have been observed which include, for example, the characteristics of moment-curvature envelope curve and the variation of neutral axis depth. |
| Full Text: | View full text in PDF format (594KB) |
| TOC: | Back to Table of Contents |
|
|
