钢框架-中心支撑结构强度折减系数研究

发布时间：2018-06-08 04:01

本文选题：钢框架-中心支撑结构 + 强度折减系数　；参考：《河北工程大学》2017年硕士论文

【摘要】：钢框架-中心支撑结构体系初始抗侧刚度大,支撑失效后,框架作为储备体系可以继续承担侧向荷载,合理的抗震设计对于结构的安全性有着重要作用。历次震害表明,由于设计的不合理导致钢框架-中心支撑体系的储备能力不足,造成了结构发生不同程度的破坏,严重的时候甚至发生倒塌,钢框架-中心支撑结构的储备体系对其抗震性能影响显著。因此,在结构抗震设计中应考虑储备体系的作用。结构设计中,地震作用通常采用强度折减系数对弹性强度进行折减获得,因此确定适用于钢框架-中心支撑结构的考虑储备系数的强度折减系数,是该体系抗震研究的关键。本文以单自由度钢框架-中心支撑体系为基础,利用动力时程分析方法,分析了延性、储备系数、阻尼比对结构强度折减系数的影响。结果表明:强度折减系数的取值随延性的提高而显著增大,低延性结构应考虑刚度储备对强度折减系数的影响,延性反应较大的中长周期结构应考虑强度储备的影响。最终给出了考虑储备系数的钢框架-中心支撑结构R-μ-T模型,对该类结构的设计提供重要参考。此外采用pushover分析将多自由度转换为以第一振型为主的等效单自由度体系,并基于单自由度钢框架-中心支撑结构R-μ-T模型提出了简化的位移评估方法,依据一个钢框架-中心支撑实例,采用该方法确定结构的顶点位移,与传统时程分析方法进行比较,验证了单自由度钢框架-中心支撑结构体系强度系数在多自由度钢框架-中心支撑结构体系的适用性。计算结果表明:采用本文提出的单自由度钢框架-中心支撑结构的R-μ-T模型可以对钢框架-中心支撑结构体系的最大顶点位移进行评估,指导多自由度钢框架-中心支撑结构体系的抗震设计和性能评估。
[Abstract]:The initial lateral stiffness of steel frame-center-braced structure system is large. After the failure of bracing, the frame can continue to bear lateral load as a reserve system. Reasonable seismic design plays an important role in the safety of the structure. The previous earthquake damage shows that due to the unreasonable design, the reserve capacity of the steel frame-central bracing system is insufficient, resulting in the destruction of the structure to varying degrees and even collapse in serious cases. The reserve system of steel frame-center braced structure has a significant effect on its seismic performance. Therefore, the role of reserve system should be considered in seismic design of structures. In structural design, the strength reduction coefficient is usually used to reduce the elastic strength, so it is the key to determine the strength reduction coefficient which is suitable for the steel frame-center braced structure to consider the reserve coefficient. Based on the single-degree-of-freedom steel frame-central bracing system, the influence of ductility, reserve coefficient and damping ratio on structural strength reduction coefficient is analyzed by using dynamic time-history analysis method. The results show that the value of strength reduction coefficient increases significantly with the increase of ductility. The influence of stiffness reserve on strength reduction coefficient should be considered in low ductility structure, and the effect of strength reserve should be considered in medium and long period structures with large ductility response. Finally, the R- 渭 -T model of steel frame-center braced structure considering the reserve coefficient is given, which provides an important reference for the design of this kind of structure. In addition, the multi-degree-of-freedom system is transformed into an equivalent single-degree-of-freedom system based on the first vibration mode by pushover analysis, and a simplified displacement evaluation method is proposed based on the R- 渭 -T model of the steel frame-center braced structure with single degree of freedom. According to an example of steel frame-center bracing, this method is used to determine the vertex displacement of the structure, which is compared with the traditional time history analysis method. The applicability of the strength coefficient of single-degree-of-freedom steel frame-center-braced structure system in multi-degree-of-freedom steel frame-center-braced structure system is verified. The results show that the R- 渭 -T model proposed in this paper can be used to evaluate the maximum vertex displacement of the steel frame-center braced structure system. To guide the seismic design and performance evaluation of multi-DOF steel frame-center braced structure system.
【学位授予单位】：河北工程大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU391

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