Temperature Variation of Foil Strain Gage by Ambient Air Condition : Series A : Solid-Mechanics, Strength of Materials

Abstract

The temperature variations of strain gages, caused by the power dissipated in the gage are calculated by the three-dimensional finite element method. When gages are bonded to materials with lower thermal diffusivities, such as plastic, the rise in the temperature of the gages depends not only upon the area of the grid of the gage, which is often used to characterize the heat-dissipation characteristics of a strain gage, but upon the length and the width of the filament, and the number of filaments. When gages are bonded to materials with higher thermal diffusivities such as steel or alumimum alloy, most of the temperature rise is produced in the base of the gage, so as to depend upon the heat flux per unit area of filament and the thickness of the base. Temperature variations of strain gages caused by ambient-temperature variations with time are also calculated using an axis-symmetrical model. In various conditions of a gage installation, the effective factors which govern temperature variation were clarified.