抄録
There have been many papers and publications affirming that the moduli of elasticity of plastics vary according to the type of loading-uniaxial tension, uniaxial compression or simple bending.
The main purpose of the present study is to clarify whether or not such inconsistencies have been brought about by the intrinsic character of the mechanical behavior of plastics. In the first place, the moduli of elasticity in bending Eb and in tension Et have been measured in a common but more precise manner, and their comparative studies have been performed. In the second place, whether or not there is any difference between Et and the moduli of elasticity in compression Ec has been examined by bending the composed beam of plastics and metal.
The following results have been obtained for various kinds of plastics sheets as conclusion. The differences among Et, Ec and Eb as shown in many publications have been caused not by the intrinsic characteristic of the mechanical behavior of plastics but by some other factors. In determing Eb, care should be taken that the measurment should be carried out by the use of specimens with suita-ble width.
