【摘要】 本文运用动态有限元法研究具有不变轴向力的梁式结构,提出了在轴向力作用下梁单元的各阶动约束模态函数的概念,并用其组成结构有限单元的各阶动态形函数矩阵。利用递推方法计算结构的各阶固有特性。文中还阐述了:利用单元的各阶动态形函数和各阶模态位移分量求出结构的各阶模态应力分量,再迭加各阶模态应力分量即可求出结构动应力近似值的方法。更多还原

【Abstract】 This paper studies the dynamic stress in beam structure subject tononvariant axial force by dynamic finite element method, and presents theconcept bf dynamic constraint mode function for each order of the beamelement loaded by axial force.With it the dynamic shape function matricesof each order of the strutucral finite element are formed. The naturalcharacteristics of the structure are calculated with the recurrence method. Bymeans of the dynamic shape function matrices and the mode displacementcomponent of each order of the element, the structural mode stresscomponent of each order is determined,and superposing them, the approximatevalue of the structure’s dynamic stress can be calculated.更多还原