高强钢管高强混凝土柱抗冲击性能与设计

High strength materials and high performance structural members are the tendency in modern construction practice. High-strength concrete filled high-strength steel tubular (HCFHST) columns mainly serve as major structural members in grand constructions corresponding to the inherent mechanical characteristics and performances. Therefore their impact resistance has been attracting extensive attention by researchers. The dynamic response of HCFHST columns under impact loading is one of the key issues in the related investigations, based on which design methods corresponding to various fortification grades can be proposed. In this context, the strain rate effects of high-strength steel and high-strength concrete will be first investigated, and the responses of circular HCFHST columns subjected to lateral impact loading will be studied as principal knowledge contribution. A variety of key parameters, such as material strengths of steel and core concrete, steel ratio, and impact energy, will be included to quantify their influences on the impact force, mid-height deflection, energy absorption ability, dynamic magnification factor and dynamic load-bearing capacity of such high-strength composite members. Analytical models and design equations will be developed for predicting the dynamic strength of members, and design methods and recommendations will be proposed. The research will be conducted to investigate the stress mechanism of HCFHST columns under lateral impact forces, to improve the design theory and method of concrete-filled steel tubes and their application in practice, and to promote the development of high performance building industry in China.

材料高强化与构件和结构高性能化是工程结构的发展趋势，高强钢管高强混凝土柱的受力特点与力学性能，决定了其应用将主要作为重要建筑中的主要受力构件，抗冲击性能日益受到关注。研究高强钢管高强混凝土抗冲击性能，提出满足不同设防等级的抗冲击设计方法，是高强钢管高强混凝土研究的关键问题。为此，项目将基于高强钢材与高强混凝土应变率效应研究，以高强钢管高强混凝土柱在侧向冲击荷载作用下的力学性能为关键科学问题，以钢材与混凝土强度、含钢率、冲击能量等为关键参数，研究冲击力、跨中挠度、能量吸收、动态放大系数、极限承载力等关键指标，建立高强钢管高强混凝土柱侧向冲击承载力分析模型与设计公式，并提出相应设计方法与设计建议。上述工作将揭示高强钢管高强混凝土在动态荷载下的受力机理，进一步完善钢管混凝土设计理论与方法，进而推动钢管混凝土结构的应用与实践，促进我国新型高性能建筑结构产业的蓬勃发展。

冲击作为土木工程结构致垮的三大灾害（地震、火灾、冲击）之一，已成为绝大多数重大土木工程结构、桥梁结构、防撞围护结构、国防抗爆与防恐设施等必须考虑的偶然作用，主体结构构件的抗冲击性能研究亟待开展。项目以高强钢管高强混凝土构件为主要研究对象，从材料、构件和设计三个层面对其展开了抗冲击性能的系统研究：开展了多强度结构钢与混凝土静态与动态材料力学性能试验研究，建立了全强度范围（屈服强度为235-960) 的结构钢动态力学本构模型，拓展了现有混凝土动态力学本构模型的适用范围；完成了系列高强钢管高强混凝土构件及普通强度钢管混凝土构件的侧向落锤冲击性能的试验研究与数值分析，提出了基于冲击能量的高强钢管高强混凝土构件侧向抗冲击设计方法。项目为钢结构与组合结构构件的抗冲击分析提供了材料动力本构模型等研究基础，为钢管混凝土构件抗冲击性能设计提供了计算方法与设计建议，完善了钢管混凝土结构的分析理论与设计体系。