题  目：新一代结构工程实验室的发展

Development of Next Generation Structural Engineering Laboratories

报告人：杨宗元，加拿大不列颠哥伦比亚大学副教授

时  间：2017年6月16日 上午10:00—11:30

地  点：励吾科技5楼会议室（516室）

欢迎广大师生参加

                       土木与交通学院

                       2017年6月15日

报告人简介：

杨教授研究主要集中在通过仿真模拟和实验测试来改进结构的抗震性能方面。他编写了新版基于性能设计的设计指南（adopted by the Applied Technology Council, the ATC-58 research team）；开发了先进的实验检测技术，以评估极端荷载条件下的结构响应；为北美和南美国家设计了基于风险仿真的模型，为东南亚国家设计了GEM模型（Global Earthquake Model）。杨教授的研究成果被广泛应用于国外内研究领域和规范制定委员会，他已经被全世界超过四十个领先的研究机构邀请过去展示他的研究成果。杨教授是加拿大抗震常务委员会、美国钢结构协会（AISC）和美国高层建筑倡议项目（ Tall Buildings Initiative Project）的成员，同时兼任同济大学地震工程国际合作联合实验室(International Joint Research Laboratory of Earthquake Engineering)的执行主任。

报告摘要：

The knowledge of earthquake engineering is largely gained through experimental testing. The most direct method to recreate the loading experienced by a structure during an earthquake is via shaking table testing. Conventional shake tables employ linear controllers such as proportional-integral-derivative (PID) or loop shaping to regulate the movement. However, it is difficult to tune a linear controller to achieve accurate and robust tracking of different reference signals under payloads. The challenges are mainly due to the nonlinearity in hydraulic actuator dynamics and specimen behavior. Moreover, tracking a high frequency reference signal using a linear controller tends to cause actuator saturation and instability. In this presentation, a hierarchical control strategy is proposed to develop a high performance shake table. The high-level controller utilizes the Sliding Mode Control (SMC) technique to provide robustness to compensate for model nonlinearity and uncertainties experienced in experimental tests. The performance of the proposed controller is compared with a state-of-the-art loop shaping displacement-based controller. The experimental results show that the proposed hierarchical shake table control system with SMC can provide superior displacement, velocity and acceleration tracking performance and improved robustness against modeling uncertainty and nonlinearities. In addition to shaking table testing, hybrid simulation (HS) is becoming a favorable alternative experimental method to shaking table test. This is particularly useful for the development of novel structural components and systems, where only a small portion of the structure needed to be experimentally tested. Traditionally, HS is displacement-based. Many successful tests have been accomplished. However, such a methodology is not suitable for specimens with high stiffness. In this presentation, a hierarchical displacement-based and force-based control framework for HS is presented. In this framework, a high-level controller generates either the force or displacement commands based on finite element formulation and regulated the force or displacement commend using low-level controller(s). A detailed formulation for the high-level controller is presented.