ARORA J.S. The University of Iowa, Civil Engineering, Professor, 工学部, 教授
SMITH T.F. The University of Iowa, Mechanical Engineering, Professor, 工学部, 教授
|Budget Amount *help
¥1,000,000 (Direct Cost : ¥1,000,000)
Fiscal Year 1998 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 1997 : ¥500,000 (Direct Cost : ¥500,000)
Many civil engineering structures are exposed to the natural environment and thus, they are subjected to the change of climate. It is the purpose of this study to investigate the effects of the nature on the structures by modeling the natural phenomenon. In order to achieve the purpose, it is essential to establish an interface model between the structures and the surrounding environment.
External factorsthat affecttemperature change in them aremeteorological actions such as air temperature, solar radiation, sky radiation, wind velocity, and water evaporation. Also those which need to be considered are the densities, specific heats and thermal conductivity of a structure and surrounding soil, and a heat source if it exists. The most complicated is the interface condition between sfructural surfre and the surrounding environment. Convective heat transfer, short wave radiation and long wave radiation have to be taken into consideration and further latent heat should be included is the suifaceis watered. Throughthe heat transfer analysis along with the interflice model, thermal change in a body of structure can be estimated.
A question here is verification of the interface model. Joint research with a private company is also undertaken and a field expenment has been conducted to observe the interaction between a structure and meteorological factors. The upward and downward solar radiation, the upward and downward sky radiation, dewpoint temperature, wind velocity and body temperature of concrete have been monitored over one year. Through the experiment, it is aimed to establish the interface model that meets the seasonal as well as weather changes. Judging from over all outcomes, it has become apparent that a body temperature of concrete to the environmental effects can be very well estimated except the period of rainy days.