带中间铰支的压杆比较常见。把铰支看作刚度无穷大的弹性支承,并利用脉冲函数,建立带中间铰支压杆的运动微分方程,利用微分求积法(DQ method)得到复特征方程。通过求解复特征方程,得出压杆复频率与轴向压力的变化关系,以及铰支位置对杆长度系数的影响。计算结果表明:随着铰支位置从固定端逐渐移向自由端,长度系数按照一定规律从2降低为0.699。
Compressed column with intermediate hinged-support is a very useful structure.We treat the hinged-support as a elastic support with unlimited stiffness and simulate it with delta function.Differential equation of motion is established.By using DQ method,numerical results of the eigen value equation were calculated.The relationship between frequency and compressive load and the relationship between length coefficient and its position is obtained.The result shows that when the hinged-support moves from the clamped end to the free end,the length coefficient decreases from 2 to 0.699 gradually.