Abstract: This paper briefly describes the significance of thermal deformation in scientific research and production. It points out the limitations of the traditional method for calculating the thermal expansion and the important effect of geometrical parameter on the thermal expansion deformation of mechanical parts. The relationship between the geometrifcal body parameter and the thermal expansion coefficient is analyzed through theoretical discussion and experiments. A preliminary investigation into the relationship between the value of thermal expansion due to the geometrical parameter and the value of traditional thermal expansion has been curried out through experiments.

Key words: thermal expansion, geometrical body parameter, thermal expansion coefficient