Introducing the Heaviside function, the thickness of the plate h(r) is displaced by a step curve (1) and adopting the modified iteration method, the second approximate solution for this model is obtained.

• 求解当中,先用一条阶梯曲线[1]来代替板厚h(r),引用Heaviside函数,然后给出任意变厚度圆薄板的修正迭代程序,直接求解方程,得到了二次近似解。