具有初始挠度的板架结构承载特性分析

为探讨具有初始挠度的板架结构轴向受压时的承载特性,本文采用MSC.Nastran建立了具有初始挠度的板架结构模型,分析了初始挠度及其大小对结构的影响,根据应力等效原理拟合了挠曲板架结构轴向受压时的相当面积公式。结果表明,随着初始挠度的增加,板架主要变形方式逐渐由压缩转换为弯曲,其承载能力大幅下降;初始挠度越大,板架承载能力越弱;相当面积折减系数随着初始挠度的增加呈现先缓慢减小随后迅速降低最终平减小的变化趋势,结构中横向(垂直于轴向)应力随着初始挠度的增加不断增大。

Research on the bearing characteristics of grillage structure with initial deflection

To explore the bearing characteristics of deck grillage with initial flexural deformation,the finite element models of flexural grillage were constructed using MSC.Nastran.The influence rules of initial deformation on the bearing capacity behavior under uniform compression loads were analyzed.The fitting curve as well as its expression of the effective section area reduction coefficient was drawn according to stress equivalence principle.It was shown that the deformation mode was transformed form compression to bending with the initial deflection increased and the bearing capacity decreased greatly.The effective area reduction coefficient firstly decreased slowly and then sharply with the increase of initial deflection and it slowed down finally.The transverse stress(vertical to the axis)increased consistently as the initial deflection increase.