基于残余应力的复合阻尼模型及在RC梁损伤分析中的应用

发布时间：2019-06-30 20:43

【摘要】：传统阻尼模型包括黏滞型、库仑型、复阻尼型及应力型等,以上模型在表征阻尼随结构损伤演变的变化规律方面存在不足。认为钢筋混凝土结构的阻尼耗能主要包括黏滞阻尼耗能和残余应力阻尼耗能,且残余应力包括钢筋和混凝土之间的黏结应力以及混凝土裂缝间的摩擦应力。在此基础上提出基于残余应力的复合阻尼模型,并建立包含黏滞和库仑阻尼的结构动力方程,推导阻尼比随损伤变化公式。分析不同损伤程度下钢筋混凝土结构的阻尼比变化规律,发现残余应力与刚度的比值明显影响损伤过程中阻尼的变化趋势,且复合阻尼模型的参数丰富,适应性强。最后,通过钢筋混凝土简支梁静力损伤试验测试阻尼随损伤程度的变化,结合数值模拟研究阻尼比随损伤程度变化的机理。结果表明:提出的阻尼模型具有明确的力学机理,能够准确地反映钢筋混凝土梁式结构阻尼比随损伤先增大后减小的规律。
[Abstract]:The traditional damping models include viscous type, Coulomb type, complex damping type and stress type. The above models are insufficient to characterize the variation of damping with structural damage evolution. It is considered that the damping energy dissipation of reinforced concrete structures mainly includes viscous damping energy dissipation and residual stress damping energy dissipation, and the residual stress includes the bonding stress between steel bar and concrete and the friction stress between concrete cracks. On this basis, a composite damping model based on residual stress is proposed, and the structural dynamic equation including viscous and Coulomb damping is established, and the formula of damping ratio with damage is derived. The variation of damping ratio of reinforced concrete structures under different damage degrees is analyzed. It is found that the ratio of residual stress to stiffness obviously affects the changing trend of damping during damage, and the composite damping model has rich parameters and strong adaptability. Finally, the change of damping with damage degree is tested by static damage test of reinforced concrete simply supported beams, and the mechanism of damping ratio changing with damage degree is studied by numerical simulation. The results show that the proposed damping model has a clear mechanical mechanism and can accurately reflect the law that the damping ratio of reinforced concrete beam structure increases at first and then decreases with the damage.
【作者单位】：北京工业大学工程抗震与结构诊治北京市重点实验室;首都世界城市顺畅交通北京市协同创新中心;
【基金】：国家自然科学基金资助项目(51378039,51421005,51478024,91315301-03)
【分类号】：TU375

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