双曲率钣料力学展开法

Mechanical Expansion Method for Double Curvature Plate

本文考虑了船体外钣在弯曲加工过程中弹-塑性复杂变形的影响,提出了一种包括这些力学因素的展开方法,求出了较为精确的展开轮廓。文中首先分析形变。得出位移应力的协调方程,再由受力平衡条件,考虑了复杂应力-应变的塑性关系,给出适当应力函数及钣料形状的表征函数,设定边界条件,求出钣料中性层平面的位移量。最后对二种常见的曲率对称矩形钣进行了计算,采用曲率参数K=(4f_xf_y)/a^2,求出其位移量。知其在K≤5×10^(-8)的范围内,用虎克特性规律进行估算,在实用上有足够的精度。

In consideration of the complex elastic-plastic deformation of the shell plate when it is bent,this paper presents a new expansion method instead of the geometric method to derive an accurate shape of plates when marked off. This paper obtains a compatibility equation of displacement stress, gives an appropriate stress function and a characteristic function of the plate's form, assumes the boundary condition so as to derive the displacement, and calculates two ordinary curvature asymmetric shell plates. It shows that the curvature parameter performs in accordance with Hooke's Law, and sufficient accuracy in practical use is available.