部分预应力砼梁开裂截面中和轴高度的一般方程及简化计算

General Equation and Simplified Calculation for Determining Neutral Axis in Partially Prestressed Concrete Beam after Cracking

本文导出了最一般的双筋T形或工形截面部分预应力砼梁开裂后截面中和轴高度的基本方程,并对其作了分析讨论。为简化三次方程的求解,且保证有足够的计算精度,文中给出了三次逼近式。此法不仅可简便地计算各种截面的部分预应力砼梁,而且也适用于钢筋砼偏心受力构件的受压区高度计算。文末附有计算实例。

A general equation for determining the neutral axis in partially prestressed concrete T or I Section beams with tension and compression reinforcement is presented in this paper. Some important analyses and discussions about the equation are made in detail. A simplified approach by which a cubic equation is approximated by a quadratic equation with acceptable accuracy is proposed. This method is also adaptable to problems of solving the neutral axis for reinforced concrete members subjected to eccentric compressive or tensile force. Numerical examples are given at the end of the paper.