冲击与火作用下弹塑性梁的动力响应及LTB研究

项目名称： 冲击与火作用下弹塑性梁的动力响应及LTB研究

项目编号： No.10872117

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 轻工业、手工业

项目作者： 席丰

作者单位： 山东建筑大学

项目金额： 34万元

中文摘要： 本研究项目以结构抗火、抗爆等防灾减灾防护工程为研究背景，以冲击动力学、结构火工程理论为基础，通过实验量测和建立能够进行有效计算的统一数学模型，并编制计算程序进行数值模拟，系统分析了受到两类不同载荷即冲击、爆炸载荷和火载荷作用下梁结构的响应与失效行为，讨论了两类载荷的相互作用效应，即由于高温导致的材料退化行为和膨胀变形对结构动力响应和变形模式的影响，惯性效应、应变率效应对于结构抗火性的影响；提出了抗火计算的新方法，并基于包含截面弯矩和轴力的广义屈服函数，给出了大挠度梁的两个极限温度准则；还建议了时间步长与空间步长的一个新的关系式，确保在用有限差分法求解梁的大挠度弹塑性动力响应时能够得到稳定的数值解；实验观察发现了在撞击载荷作用下梁的侧向弯扭屈曲（LTB）现象。对于得到的这些重要结果,目前已完成学术论文12篇，部分结果已发表在International Journal of Impact Engineering, Science China等SCI检索核心期刊。这些所建议的新方法、准则和公式丰富了人们对于冲击动力学和结构火工程理论的认识，也将为工程结构的防爆、防火设计提供参考依据。

中文关键词： 弹塑性梁;冲击与火;计算模型;极限温度准则;弯扭屈曲

英文摘要： The engineering background for this research project is the structural fire resistance and blast-resistant design. Based on the theory of impact dynamics and structural fire engineering, the response and failure behavior of beams subjected to impact,blast and fire loading was systematic studied through experiment and numerical simulation, an unitied computing model was proposed so that to make effective calculation and corresponding FORTRAN program was developed. The interaction effect between two types of load, that are the influence of thermal expansional deformation and retrogradation of material mechanical property inducted by elevated temperature on the mode of deformation and dynamic response, the effects of strain rate and inertia on the fire resistance of structure, was discussed in detail. For the large deflection beam, a novel approch to study fire resistance of beams and two limiting temperature criteria based on the generalized yield function consisting of bending moment and axial force on the cross-section were presented. A computational stability requirement to determine the relationship between the time-step and the element size was proposed, it could make sure to obtain the stable numerical solution for the dynamic response of large deflection elastic-plastic beam by finite difference method. The phenomenon of lateral torsional buckling for the beams under impact loading was also found by experiment. For these important results, about 12 academic papers have been completed and partial results have been published on SCI journal such as International Journal of Impact Engineering, Science China. All these proposed new method, criterion and results developed the impact dynamics and structural fire engineering, and would provide a theoretical basis for the fire resistance and blast-resistant design of engineering structures.

英文关键词： elastic-plastic beam;impact and fire; computing model;limiting temperature criterion;lateral torsional buckling