This historical note reports on the early days of the development of an experimental method called “hybrid simulation.” As background, the seeds of this concept, initiated in the early 1970s by Japanese researchers, are presented first, followed by initial efforts (regarded as Stage I) to realize the concept of hybrid simulation and its first applications to explore the seismic performance of structures. The initial research in this now‐seminal field of earthquake engineering began in the early 1970s by Koichi Takanashi and his coworkers at the Institute of Industrial Science, the University of Tokyo. Their highly notable efforts in laying the groundwork for hybrid simulation occurred in the mid‐1970s through the early 1980s by Takanashi (for steel structures) and Tsuneo Okada (for RC structures). These two men and their coworkers first applied hybrid simulation to explore the seismic behavior, performance, and design of various types of building structures. In Stage I, this method was called “the on‐line computer‐controlled test” or “pseudo dynamic test” because the unique feature of the method was the combined test and simulation and the intentional slow loading in the test. Extension of the scope and application of hybrid simulation occurred largely between the early 1980s and the early 1990s (regarded as Stage II) in conjunction with the United States–Japan joint research project. A few notable efforts made around that period are touched upon briefly, including error propagation and suppression in multi‐degree‐of‐freedom hybrid simulation, application of the substructure methodology to hybrid simulation, and real‐time hybrid simulation.

中文翻译：

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混合仿真：早期的历史

此历史记录报告了开发称为“混合仿真”的实验方法的早期情况。作为背景，首先介绍了由日本研究人员于1970年代初提出的这一概念的种子，然后进行了初步努力（被视为第一阶段）以实现混合仿真的概念及其在探索结构抗震性能中的首次应用。 。当今的地震工程领域的最初研究始于1970年代初，东京大学工业科学研究所的高桥孝一（Koichi Takanashi）及其同事。他们在进行混合仿真奠定基础方面所做的杰出工作是在1970年代中期至1980年代初，当时Takanashi（用于钢结构）和Tsuneo Okada（用于RC结构）。这两个人及其同事首先应用混合仿真来探索各种建筑结构的抗震性能，性能和设计。在阶段I中，此方法被称为“在线计算机控制测试”或“伪动态测试”，因为该方法的独特之处在于将测试与模拟结合起来，并在测试中故意进行缓慢加载。结合美国-日本的联合研究项目，混合仿真的范围和应用的扩展主要发生在1980年代初至1990年代初（被称为第二阶段）。简要介绍了在此期间所做的一些值得注意的工作，包括多自由度混合仿真中的错误传播和抑制，子结构方法在混合仿真中的应用以及实时混合仿真。