抄録
Graphical method for the heat conduction problems were already discussed by Schmidt, Osida, Emmons e.t.c.. But when the thermal diffusivity κ is a function of temperature or space, few ones were discussed. Thereupon, we discussed one method for the two-dimensional heat flow problems when κ is a function of temperature, and applied this method for a practical problems to find the temperature distribution of a reinforced concrete construction which is heated by a fire and its κ decreases by the elevation of its temperature. As an example, we showed the graphs of the temperature distribution of a member which is heated by the 3rd class fire of J.I.S.A 1302. This paper is a fundamental research to calculate the thermal stress which is caused by a fire.
