A shaking test system for testing a structure including a shaking device for shaking the structure, measuring devices mounted on the shaking device for shaking the structure, external signal input device for inputting data indicative of external force for shaking the structure, as well as other calculating arrangements. The shaking test system permits the setting of a large time interval of a shaking test by converting natural modes of vibration expressed by a second-order differential equation, namely second-order lag system of a vibration differential equation into a first-order lag system or (O)th order lag system for short period mode.

Damped structures with isolators such as, for example, total vehicles, are analyzed and automatically optimized using a model representing the structure, the model possibly consisting of both rigid and flexible components, together with initial values for isolator design variables, a set of design constraints, and an optimization criterion. Each isolator may have frequency dependent or frequency independent parameters. Excitations may come from a combination of internal and external sources that may be expressed as deterministic or random functions. Finite element modeling is used to determine eigenvectors of flexible finite element components. A total system model is obtained using the rigid component parameters, eigenvectors of flexible components, and spring-damping parameters of isolators. Vibration analysis using the total system model yields system frequency responses and an optimization function. The Method of Feasible Directions is used to produce optimized isolator design variable values based on the optimization function. A graphical user interface assists the user in entering variables, selecting options, and post-processing.

Apparatus is disclosed for protecting a structural object from the potentially harmful effects of a cyclic event such as an earthquake or high wind loads. A fluid spring is employed to stiffen the structural object and absorb kinetic energy stored by the spring. Fluid from the spring is exchanged with an accumulator where kinetic energy is dissipated as heat. A flow circuit regulates the exchange of fluid between the spring chamber and the accumulator chamber under controlled conditions to absorb the harmful effects of high external loads and to release the structural object when a high shock load is experienced.

An oil pressure damper device for an architectural structure and a monitor and control system of the damper device without requiring an exclusive network for connecting between the damper devices and the monitor and control system, and is able to monitor operations without regard to the distance between the damper devices and the monitor system. The oil pressure damper device includes a detection unit for detecting conditions of the damper device, a communication unit for transmitting information detected by the detection unit through a public communication network and/or a local area network, and a monitor for receiving the information from the communication unit and monitoring the conditions of the damper devices of the architectural structure.

A house 2 is isolated from the foundation 1 by a rolling bearing 3. A vibration control device 6 with a releasable rigid connector 5 is added in parallel to the rolling bearing 3. Further, a release controller 8 of the rigid connector 5 is connected to the output end of an earthquake detector 7 on the house 2, so as to release the rigid connector 5 in response to output signal from the earthquake detector 7. Thus, the building 2 normally stands without vibration against wind by rigid connection to the foundation 1 through the rigid connector 5. On the other hand, when earthquake occurs, the rigid connector 5 is released by the release controller 8 by the output from the earthquake detector 7, so as to control the vibration of the building 2 by a combination of the rolling bearing 3 and the vibration control device 6.