（太原理工大学建筑与土木工程学院，太原 030024）

［摘要］强震下空间网格结构的杆单元由于塑性发展、损伤累积导致刚度退化严重，对结构性能影响极大。为研究强震下组合试件的损伤特性，设计了管球组合试件的轴向加载试验。通过3种不同的加载制度研究试件的挠度发展规律，并基于累积耗能与承载力退化提出两种评价管球组合试件发生不同程度疲劳破坏的损伤模型，同时对滞回曲线和骨架曲线的发展规律进行了初步分析。结果表明：空间挠度变化规律可作为试件损伤极限的宏观演化反映；两种损伤模型曲线表明以试件开口作为损伤极限状态是合理性的；试件的滞回曲线在临近开口时有明显衰退现象；骨架曲线在受压阶段有显著的刚度退化。

［关键词］挠度曲线；疲劳损伤试验；滞回曲线；骨架曲线；损伤模型；损伤极限状态

中图分类号：TU391文献标识码：A文章编号：1002-848X(2020)24-0024-05

Experimental study on fatigue damage of tube and ball combined specimens under reciprocating loading

ZHANG Jie, LI Haiwang, CHEN Xueyong, SONG Xiayun, LI Yanying

(College of Architecture and Civil Engineering, Taiyuan University of Technology, Taiyuan 030024, China)

Abstract:The rod element of the space grid structure under strong earthquake has serious stiffness degradation due to plastic development and damage accumulation, which has great influence on the structural performance. In order to study the damage characteristics of combined specimens under strong earthquakes, axial loading tests of tube and ball combined specimens were designed. The development law of  deflection of the specimens was studied by three different loading systems,and based on the cumulative energy dissipation and the bearing capacity degradation, two damage models were proposed to evaluate the different degrees of fatigue failure of  tube and ball combined specimens, and preliminary analysis of the law of the hysteresis curves and skeleton curves development was carried out. The results show that the law of  deflection can be used as a macroscopic evolution of the damage limit of specimens. The two damage models curves indicate that it is reasonable to use the specimen opening as the damage limit state. The hysteresis curve of the specimens has a significant decline when it is adjacent to the opening. The skeleton curve has significant stiffness degradation during the compression phase.

Keywords:deflection curve; fatigue damage test; hysteresis curve; skeleton curve; damage model; damage limit state

*国家自然科学基金项目(51578358)。

作者简介：张洁，博士研究生，Email：mayzj@126.com；通信作者：李海旺，博士，教授，博士生导师，Email：lhwtut@126.com。