预应力砼梁开裂截面压应力计算的简化方法

A new way of calculating the normal stresses on re-cracked cross sections of prestressed concrete beams

根据预应力砼梁再开裂正截面预应力钢筋的应力计算经验公式,推导梁正截面首次开裂后再开裂过程中中性轴位置和受压区边缘砼正应力的计算新方法,其间考虑了预应力砼梁正截面首次开裂以及疲劳荷载重复作用对钢筋和砼应力增长的影响,并通过算例对新方法与现有方法的计算结果进行比较,验证了新方法的简便合理性.

Based on the empirical formulae calculating the tendon stresses on re-cracked cross sections of prestressed concrete beams, the positions of neutral axes and the normal stresses of compressive concrete edge fibers on re-cracked cross sections of prestressed concrete beams are determined in a new way, the amplifying effects of the first-time cracking and the cycling fatigue loads on the steel bar stresses and concrete stresses considered. A exemplificative prestressed concrete cross section is calculated with the new method as well as with the traditional one to prove the simplicity and accuracy of the new one.