Department of Civil Engineering, School of Transportation Science and Engineering, Beihang University, Beijing, 100191, People's Republic of China.
J Acoust Soc Am. 2011 Nov;130(5):2728-37. doi: 10.1121/1.3647303.
This paper presents a theoretical and experimental study of the nonlinear flexural vibration of a cement-based material with distributed microcracks caused by an important deterioration mechanism, alkali-silica reaction (ASR). The general equation of motion is derived for the flexural vibration of a slender beam with the nonlinear hysteretic constitutive relationship for consolidated materials, and then an approximate formula for excitation-dependent resonance frequency is obtained. A downward shift of the resonance frequency is related to the nonlinearity parameters defined in the constitutive relationship. Vibration experiments are conducted on standard mortar bar samples undergoing progressive ASR damage. The absolute nonlinearity parameters are determined from these experimental results using the theoretical solution in order to investigate their dependence on the damage state of the material. With the progress of the ASR damage, the absolute value of the hysteresis nonlinearity parameter increases by as much as six times from the intact (undamaged) state in the sample with highly reactive aggregate; this is in contrast to a change of about 16% in the linear resonance frequency. It is demonstrated that the combined theoretical and experimental approach developed in this research can be used to quantitatively characterize ASR damage in mortar samples and other cement-based materials.
本文针对由重要劣化机制——碱硅酸反应（ASR）引起的分布式微裂缝对水泥基材料的非线性弯曲振动进行了理论和实验研究。针对具有非线性滞后本构关系的细长梁的弯曲振动，推导出了运动的一般方程，然后得到了与激励相关的共振频率的近似公式。共振频率的下移与本构关系中定义的非线性参数有关。对经历渐进 ASR 损伤的标准砂浆棒样品进行了振动实验。使用理论解从这些实验结果中确定绝对非线性参数，以研究它们对材料损伤状态的依赖性。随着 ASR 损伤的进展，在高反应性骨料的样品中，从完整（未损坏）状态开始，滞后非线性参数的绝对值增加了多达六倍；相比之下，线性共振频率的变化约为 16%。结果表明，本文研究中开发的理论和实验相结合的方法可用于定量表征砂浆样品和其他水泥基材料中的 ASR 损伤。
