Shaking table test and verification of development of an accumulated semi-active hydraulic damper as an active interaction control device MING-HSIANG SHIH 1 and WEN-PEI SUNG 2, * 1 Department of Civil Engineering, National Chi-Nan University, Pu-Li, Nan-Tou 545, Taiwan 2 Department of Landscape Architecture, Integrated Research Center for Green Living Technologies, National Chin-Yi University of Technology, Taichung 41170, Taiwan e-mail: iloveaachen@gmail.com; wps@ncut.edu.tw MS received 17 July 2015; accepted 19 June 2016 Abstract. Semi-active control is based on the use of the emerging concept of active control and passive control. The developed accumulator semi-active hydraulic damper (ASHD) is converted to interaction element (IE) of active interaction control (AIC). Systemic equations of motion, control law and control rulers of this proposed new AIC are studied in this research. A full-scale multiple degrees of freedom shaking table is tested to verify the energy dissipation of this proposed AIC, including test building without control, with passive control added involving various stiffness ratios and also with synchronic control added involving various stiffness ratios. Shock absorption of displacement can be up to 74–81% of that of the test structure with stiffness ratio = 2.3387 and 1.790 at 1st and 2nd floor under control of synchronous switch of this proposed AIC, respectively. No matter what the test structure added with various stiffeners at 1st and 2nd floor under synchronous control, test results of shock absorption ratio of acceleration show good seismic proof capability. In addition, base shear control effects of this proposed AIC method are higher than those of the test structure with various stiffeners added under passive control. These results show that AIC with stiffeners for structural control provides the characteristics of a stabilized structure under excitation of near-fault earthquake with velocity impulse action. Keywords. Accumulator semi-active hydraulic damper (ASHD); active interaction control (AIC); stiffness ratio; full-scale shaking table test; shock absorption ratio. 1. Introduction Structures of civil engineering and architecture subjected to strong ground motion often undergo enormous deforma- tion, resulting in permanent damage to the structures or even collapse. Recently, global warming effects induced some large earthquakes around the world such as the Richter scale 9.0 event in Indonesia and Japan causing tsunami disasters and Richter scale 7.8 in Pakistan causing a new small island offshore. Also, a Richter scale 7.9 event happened in Nepal this year, causing large loss of human life and properties. These strong earthquakes bring about not only loss of many lives but also damages to many structures. Many engineers and scholars have been inspired to shelter building and civil engineering structures from this kind of earthquakes. Thus, in order to promote the seismic proof capability of structures, industry and academic soci- ety invest lots of manpower of civil engineers and material resources in studying and developing the technology of anti-seismic capability of structures. To resist invasion of seismic forces, ductility design and application of shock isolation techniques are the most often used. The main idea of ductility design is to enable inelastic deformation of structural elements to play a role of energy dissipation, thus avoiding the resonance amplification of structures. In order to ensure that structural components remain in structural stability within the range of inelastic deformation of structural elements, the detailed design of structural components must meet toughness requirements of ductility design. The advantage of this design concept is to resist earthquake forces to avoid risk of structure collapse under P–D effects of structural large deflection. The dif- ference between shock isolation technology and traditional design method is that shock isolation technology applies non-traditional beams, columns, plates, walls and other structural components of added components such as vibration isolators, stiffened dampers, dampers, tuned mass blocks, tuned liquid-column damper, etc. [1–11]. Accord- ing to the reports of international research, the cost of proper installing of a damping isolation system of the structure is lower than that of the traditional method of structural reinforcement. A damping isolation system mainly reduces dynamic characteristics by changing the *For correspondence 1425 Sa ¯dhana ¯ Vol. 41, No. 12, December 2016, pp. 1425–1442 Ó Indian Academy of Sciences DOI 10.1007/s12046-016-0570-z