Effect of Stress Amplitude on the Damping of Recycled Aggregate Concrete.
Effect of Stress Amplitude on the Damping of Recycled Aggregate Concrete.
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DOI：
10.3390/ma8085242
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发表时间：
2015-08-14
期刊：
影响因子：
--
通讯作者：
Yang Q
中科院分区：
文献类型：
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作者：
Liang C;Liu T;Xiao J;Zou D;Yang Q
阻尼表征了材料和结构的能量耗散能力，它受到振动频率、应力历史、温度和应力幅值等外部因素的影响。研究了环保再生骨料混凝土（RAC）的阻尼与应力幅的关系。首先，基于拉赞阻尼-应力函数，推导了杆件损耗因子与应力幅的函数模型。在此基础上，研究了应力幅值对再生混凝土损耗角正切的影响。最后，通过数值拟合得到了确定新导出函数的参数。结果表明，构件的损失系数不仅受应力幅值的影响，而且还受截面形状、边界条件、载荷类型和加载位置等因素的影响。RAC的损耗角正切随应力幅的增大而增大，即使在低应力幅下也是如此。RAC的阻尼能量指数不等于2.0，表明阻尼是非线性的。研究还发现，再生混凝土的耗能能力优于天然骨料混凝土（NAC）的耗能能力上级，通过掺加改性外加剂可以进一步提高再生混凝土的耗能能力。
Damping characterizes the energy dissipation capacity of materials and structures, and it is affected by several external factors such as vibrating frequency, stress history, temperature, and stress amplitude. This study investigates the relationship between the damping and the stress amplitude of environment-friendly recycled aggregate concrete (RAC). First, a function model of a member’s loss factor and stress amplitude was derived based on Lazan’s damping-stress function. Then, the influence of stress amplitude on the loss tangent of RAC was experimentally investigated. Finally, parameters used to determine the newly derived function were obtained by numerical fitting. It is shown that the member’s loss factor is affected not only by the stress amplitude but also by factors such as the cross section shapes, boundary conditions, load types, and loading positions. The loss tangent of RAC increases with the stress amplitude, even at low stress amplitude. The damping energy exponent of RAC is not identically equal to 2.0, indicating that the damping is nonlinear. It is also found that the energy dissipation capacity of RAC is superior to that of natural aggregate concrete (NAC), and the energy dissipation capacity can be further improved by adding modified admixtures.