摘要
为研究栓钉初始损伤与混凝土收缩、徐变耦合效应对组合梁力学性能及时变特性的影响,提出采用实体单元模拟抗剪栓钉,构建了钢-混凝组合梁实体滑移有限元模型,并通过试验与理论计算验证了模型的有效性。考虑不同损伤工况,从承载能力、刚度退化和界面滑移分布等方面揭示了损伤后组合梁力学性能的退化规律。研究了不对称初始损伤与混凝土收缩、徐变耦合作用对组合梁竖向变形、界面滑移、应力重分布及栓钉剪力等的影响,揭示了栓钉及其附近混凝土的损伤机理和组合梁变形及截面应力增长规律。结果表明:栓钉不对称损伤会造成组合梁界面滑移分布不对称,且相同损伤程度下不对称损伤引起的界面滑移和刚度改变分别为对称损伤工况的1.37倍和1.25倍。初始损伤在与混凝土收缩徐、变耦合作用下,最大界面滑移和栓钉剪力向损伤栓钉附近转移,混凝土翼板应力降低、型钢梁应力增加,多重耦合下组合梁的竖向变形、截面应力增长可通过建立的对数增长模型进行量化表达。
To study the mechanical properties and time-varying characteristics of initial damaged composite beams under concrete shrinkage and creep,a novel solid slip finite element model of steel-concrete composite beams was constructed by using solid element to simulate shear studs.And the model was validated by both experiments and theoretical calculation.Considering different damage conditions,the degradation law of mechanical properties of composite beams with initial damages was revealed from the aspects of bearing capacity,stiffness degradation and interface slip distribution.The coupling effects of asymmetric initial damage and concrete shrinkage and creep on mechanical properties such as the vertical deformation,interface slip,stress redistribution and shear force were investigated.The deformation and section stress growth regulations were disclosed,as well as the damage mechanism of shear studs and its nearby concrete.The results show that the local asymmetric damage induced the asymmetric distribution of interface slips.The interface slip value and stiffness change are 1.37 and 1.25 times higher than that of symmetric condition under the same damage degree.Under the multi-coupling effect of initial stud damage and concrete shrinkage and creep,the maximum interface slip and shear force transferres to the nearby stud,accompanied by the stress decrease in concrete wings and stress increase in steel beam,the vertical deformation and section stress growth of the composite beam can be expressed by the constructed logarithmic model.
作者
都方竹
张世博
邱大鹏
张月
DU Fang-zhu;ZHANG Shi-bo;QIU Da-peng;ZHANG Yue(School of Civil Engineering,Shandong Jianzhu University,Jinan 250101,China;Key Laboratory of Building Structural Retrofitting and Underground Space Engineering of Ministry of Education,Shandong Jianzhu University,Jinan 250101,China;College of Civil Engineering,Dalian Minzu University,Dalian 116650,China)
出处
《科学技术与工程》
北大核心
2025年第29期12601-12612,共12页
Science Technology and Engineering
基金
国家自然科学基金(52308317)
山东省自然科学基金(ZR2024QE156)
山东省重点研发计划(重大科技创新工程)(2021CXGC011204)
山东省高等学校青创科技支持计划(2023KJ123)。
