After the 1995 Kobe earthquake in Japan, the National Research Institute for Earth Science and Disaster Prevention (NIED) constructed a new large-scale shaking table as a facility for three-dimensional earthquake damage testing, called E-Defense. The facility was completed in March 2005. E-Defense has the unique capacity to experiment with life-size buildings and infrastructural systems in real earthquake conditions, and is intended to be the ultimate verification tool. The current paper describes the specification of the facility, features of the control system, and some experimental results of the control performance tests. It also describes major ongoing projects at E-Defense.

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In many applications within the fields of science, engineering, mathematics, and socio-economics, the 'inverse problem' (i.e. the problem of determining a system's input from its output) is commonplace. The current paper presents a new concept for solving the inverse problem, which the authors call inverse dynamics compensation via 'simulation of feedback control systems' (IDCS). IDCS is a numerical method that obtains an approximate inverse dynamic solution via a feedback control simulation, using only the forward dynamic model of the linear or non-linear system. Simulations are ideal environments for feedback control, in the sense that they can be completely noise-free and precisely known, so that the IDCS method can be tuned for the best possible performance. It is seen that IDCS can use the advantages of such ideal control simulation performance in the real world of physical implementations.This paper first introduces the basic idea of IDCS. Then, the effectiveness of the proposed method is demonstrated via three illustrative examples, in which the systems to be controlled have continuous and discontinuous non-linearities. IDCS performance is also investigated via physical experimentation on a non-linear servohydraulic test rig. Finally, extensions of the basic IDCS formulation are introduced which are potentially useful for the solution of additional practical problems.

The position and effective resistance of microstructural barriers and their relation to the fatigue strength of blunt‐notched specimens are analysed and modelled for three low‐carbon steel microstructures. A relationship for the notch size effect on the basis of the experimental evidence that the fatigue limit (both plain and notched) represents the threshold stress for the propagation of the nucleated microstructurally short cracks, was derived. The derived relationship characterizes the fatigue notch sensitivity by means of the parameter ktd defined as the stress concentration introduced by the notch at a distance d from the notch root surface equal to the distance between microstructural barriers, and was experimentally verified for two notch geometries in three microstructures: ferrite, ferrite–bainite and bainite–martensite.

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