日本語/English

Wind-induced Dynamics

Wind-induced vibration of inclined stay cables

It is well known that the stay cables of cable-stayed bridges vibrate under wind and rain, which is so called rain-wind induced vibration.

In this topic, the wind tunnel tests and field observations using cable models have been tried and then, it becomes clear that this phenomenon induced by the axial flow along the cable axis due to the cable inclination, the upper water rivulet on the cable surface due to rain, unsteady and three dimensional properties of vortices around inclined cables and also mixed phenomena of these. However, there are still many unknown facts for the inclined cable aerodynamics. Then, the further investigations for their mechanisms and the development of rational countermeasures will be tried.

Earthquake-induced Dynamics

Seismic performance of infrastructural systems

Wave effect, liquefaction, fault crossing and landslide are hazard factors that provoke seismic damages of the lifeline network system which is always threatened by potentially active faults. Analytical investigation and numerical verification are necessary to develop the seismic risk assessment and retrofitting planning of the existing lifeline system which is deteriorated under various environmental conditions. In Figure 1, the system performance of the damaged network is analyzed to furnish information on restoration plans after the seismic event.

Development and verification of dynamic response of large-scale structural systems using hybrid simulation

The real-time hybrid simulation is an experimental verification technique to evaluate the dynamic response of large-scale structural systems, for which full-scale shake table testing is difficult. In this test method, the structural system is divided into a numerical substructure and an experimental substructure; response calculation of the numerical substructure with computers and dynamic loading test of structural elements using dynamic test equipments, including shake tables and dynamic actuators, are synchronously executed on a real-time basis by controlling the test procedure using the information of both processes, as a unified testing-computing dynamic simulation corresponding to the time evolution of actual dynamic phenomena. Implementation of experimental systems based on this advanced testing principle allows reliable performance validation in course of the development of advanced seismic response control devices and seismic isolation bearings.