钢柱抗爆响应分析单自由度模型适用性评估

发布时间：2018-01-13 07:28

本文关键词：钢柱抗爆响应分析单自由度模型适用性评估　出处：《爆炸与冲击》2017年05期 　论文类型：期刊论文

【摘要】：为评估单自由度(SDOF)模型在结构抗爆设计中的适用性,分别采用SDOF模型和通用有限元软件ANSYS/LS-DYNA对简支钢柱承受爆炸荷载时的动力响应进行模拟;对比二者计算结果,并以有限元模拟为准,分析SDOF模型的适用范围。研究表明:可按照自由振动阶段SDOF模型位移结果的振幅大小,将其位移响应划分为有限变形阶段、临界阶段、失稳破坏阶段,有限变形阶段SDOF模型与有限元结果基本一致;截面高宽比、翼缘宽厚比对钢柱动力破坏形式有重要影响,高宽比越大、翼缘的宽厚比越小,越容易发生平面外弯扭失稳;在SDOF模型中通过假定塑性铰分布长度计算塑性阶段应变及应变率,采用随时间变化的应变率计算Cowper-Symonds本构关系中的应力放大系数是可行的。
[Abstract]:In order to evaluate the single degree of freedom (SDOF) model is in the structure of antiknock design, were used to simulate the dynamic response of simply supported steel column under blast loading SDOF model and ANSYS/LS-DYNA finite element software; the calculation results of the two, and by the finite element simulation is accurate, the scope of the SDOF model. Show that in accordance with the amplitude of displacement results of free vibration phase of the SDOF model, the displacement response is divided into finite deformation stage, critical stage, failure stage, finite deformation stage SDOF model and finite element results; cross-section aspect ratio, flange width thickness ratio of steel column power failure mode has important effect, high the greater the width ratio, flange width to thickness ratio is smaller, the more prone to out of plane flexural torsional buckling; in the SDOF model by assuming that the calculation of plastic strain and strain rate during the length of plastic hinge distribution, using the time variable It is feasible to calculate the stress magnification coefficient in the constitutive relation of Cowper-Symonds.

【作者单位】：山东建筑大学土木工程学院;山东军之星建筑设计有限公司;
【基金】：国家自然科学基金项目(11272189)
【分类号】：O34
【正文快照】： 由于爆炸荷载传播速度快、峰值压力大、作用时间短,因此难以精确描述所引起的动力响应。为了方便结构抗爆工程应用,理想的方法是提出一些简化的分析模型,等效单自由度(single degree of free-dom model,SDOF)模型就是其中之一。GB 50009-2012《建筑结构荷载规范》中规定:由炸

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