曲梁的等效轴力及其在有限元法中的应用

The Equivalent Axial Force of Curved Beam and Its Application to Finite Element Method

由于曲率的影响，曲线梁在其曲率平面内弯曲时的中性轴不通过横截面的形心。因此弯矩在形心处要引起正应力，从而引出所谓“等效轴力”的概念。在采用曲梁有限元法分析曲梁桥或拱桥时，若忽略“等效轴力”与实际轴力的区别，会导致错误的轴向力计算结果。本文讨论这种影响产生的原因及在有限元法中如何加以考虑。

When a curved beam is bending in the plane of the curvature,the neutral axis of cross section is not identical with the axis of gravity due to the influence of the initial curvature.Therefore,the bending moment may cause normal stress at the axis of gravity,and the concept of “equivalent axial force” is induced.In the structural analysis of curved beam bridge or arch bridge by using the curved beam finite element method,the difference between the equivalent axial force and the real axial force must be considered.Otherwise,the wrong results of axial force will be brought about.In this paper, the reasons of the influence and the approach to consider the influence in finite element method are discussed.