基于半主动TMD系统的多层正交胶合木结构减震机理研究

With the rapid development of multi-storey cross laminated timber (CLT) structure, its seismic performance has important research significance. Previous research found that tuned mass damper (TMD) system can effectively reduce the seismic response of multi-storey CLT structure under its optimal condition. However, in practical applications, the uncertainties of natural frequencies caused by self-weight change and timber stiffness change can occur in the use of CLT structures, which will lead TMD system off-tuning, thus resulting in an excessive structural vibration. Therefore, based on the special material characteristics of shape memory alloy (SMA), this project intends to study the influence of temperature on the mechanical properties of SMA and its control ability. Based on the seismic dynamic characteristics of multi-storey CLT structures, this project will design an optimal SMA-based semi-active TMD control system (SMA-STMD). By conducting shaking table tests at different working temperatures, this study will establish the effect of working temperature on the dynamic mechanical properties of SMA-STMD. Through numerical simulation, the re-tuning of SMA-STMD on multi-storey CLT structure will be studied, and the control mechanism and implementable control methods based on actual cases will be proposed. The expected results can provide innovative methods for seismic control of multi-storey CLT structures and lay a theoretical foundation for the seismic control strategy based on SMA-STMD.

随着多层正交胶合木（CLT）结构的快速发展，提升其抗震性能具有重要研究意义。前期研究发现在最优条件下调谐质量阻尼器（TMD）系统可有效降低多层CLT结构的地震响应；但实际应用中，CLT结构自重变化及刚度变化导致的自振频率不确定问题会引发TMD系统与结构失调，从而引发CLT结构的过度震动问题。因此，本项目拟基于形状记忆合金（SMA）特殊的材料特性，研究温度对SMA力学特性的控制性能；基于多层CLT结构地震动力特性，优化设计SMA半主动TMD控制系统（SMA-STMD）；在不同工作温度下对SMA-STMD进行振动台试验，阐明工作温度对SMA-STMD动态力学性能的控制机制；通过数值模拟，证明SMA-STMD对失调多层CLT结构的重新调谐能力，阐明减震控制机理，并基于实际算例提出可实施的控制方法。预期成果可为多层CLT结构的减震控制提出创新方法，为基于SMA-STMD的减震控制策略奠定理论基础。

正交胶合木（Cross Laminated Timber, CLT）按照顺纹和横纹垂直交错叠合方式进行连接，胶合成高强度实木板材。CLT结构具有良好的强重比和较高的延性，但材料轻质且刚度较小，在地震作用中加速度响应过大，可能造成非结构构件的损坏。应用调谐质量阻尼器（Tuned Mass Damper，TMD）可以对其进行减震控制。由于CLT结构质量较轻，质量改变等因素很容易造成TMD失调，因此，可以利用智能材料形状记忆合金应用于调谐质量阻尼器中，对CLT结构进行半主动控制。经过实验分析，通过SMA-TMD系统的调谐、失调、重新调谐三个步骤，可实现对CLT结构的半主动控制，可解决TMD系统应用于CLT结构中易失调的问题。已按照预期完成本项目。共发表SCI论文6篇。共培养博士生1名、硕士生2名。通过线上讨论，与国际专家讨论调谐质量阻尼器结构振动控制等科研课题十余次。参加相关学术会议三次，在第十一届全国防震减灾工程学术研讨会上进行了主题为“基于形状记忆合金（SMA）半主动控制TMD系统的减震控制研究”的学术报告。