模块化钢结构梁柱子结构抗连续倒塌性能研究

PROGRESSIVE COLLAPSE ANALYSIS ON BEAM-COLUMN SUBSTRUCTURE OF MODULAR STEEL CONSTRUCTION

模块化钢结构作为一种高度预制的装配式建筑,具有工业化程度高、绿色节能环保等优点。但是,由于模块化钢结构体系超静定次数较低,其在极端荷载工况下的抗连续倒塌性能应予以特别关注。模块化钢结构梁柱子结构作为主要的传力路径,具有多梁多柱等有别于传统框架梁柱子结构的特点,需对其抗连续倒塌性能开展研究工作。该文针对采用螺栓-角件连接节点的模块化钢结构梁柱子结构进行Pushdown试验及数值模拟,分析了在双柱失效、单柱失效工况下试件的破坏模式和抗连续倒塌机理。结果表明,梁柱子结构在两种工况下的受力机理不同:在双柱失效工况下,梁柱子结构抗力主要由梁机制提供,加载后期抗力提供方式体现出一定的悬链线机制,并随水平连接板厚度的增加而增强;在单柱失效工况下,子结构抗力主要由模块间水平连接抗剪能力提供,由梁机制及悬链线机制提供的抗力较小。

Modular Steel Construction(MSC),as a highly prefabricated building,has the advantages of high degree of industrialization,of green energy conservation and of environmental protection.However,the performance of resisting progressive collapse under extreme loads for MSC should be paid special attention due to its limited degree of indeterminacy and low robustness.As the main load transferring path,the behavior of resisting progressive collapse of MSC beam-column substructure needs to be investigated,as it is different with that of traditional steel frames due to its characteristics of multi-beam and multi-column.The research conducts the Pushdown tests and numerical analyses on the MSC beam-column substructures containing the bolted module-to-module joints with corner fittings and investigates the failure mode and mechanism of resisting progressive collapse under a double-column and a single-column failure condition.The results show that the resistance mechanism of a beam-column substructure under these two failure conditions are different.Under the double-column failure condition,the resistance of substructure is mainly provided by beam mechanism and catenary mechanism,and it is significantly affected by the thickness of connecting plate;and the mode of providing resistance changes from beam mechanism to catenary mechanism with the increase of the connecting plate thickness.Under the single-column failure condition,the load is mainly undertaken by the connecting plate,causing it be tensioned and sheared,while the beam and catenary mechanism is less.