由两端弹性支承的对称梁导出对称简支梁的多项式型位移函数

Deriving Polynomial Displacement Function of Symmetric Simply Supported Beam from Symmetric Beam with Two Elastic Supports

计算了基模态和第二阶模态下两端弹性支承对称梁的多项式型位移函数,在拉伸弹簧刚度和扭转弹簧刚度满足的极限条件下,它可以导出对称简支梁的位移函数,但不能导出两端固定对称梁的位移函数。在相差一个常数因子的条件下,多项式型位移函数是唯一的。

The polynomial displacement function of symmetric beam with two elastic supports of the fundamental mode and the second-order mode is calculated.Under the limit conditions of extension spring stiffness and torsion spring stiffness,it can derive the displacement function of the symmetric simply supported beam,but it can't derive the displacement function of the symmetric beam with two fixed ends.Under the condition of a constant factor,the displacement function is unique.