Abstract
Ooject: (1) To survey the deformation of the diameter of a thread caused by twisting number and tensile load when the thread receives no compressive load.
(2) To devise an apparatus for measuring the strain when the thread is compressed; to survey the strain of the thickness and the breadth of the thread, especially the thickness when affected by twisting number and tensile load; and to establish the relation between compressive load and strain.
Findings: (1) Where the thread receives no compressive load and tensile load is small, strain increases rapidly (to the extent of about 30% of the diameter of a thread having the usual twisting number) until the interestices of the fibers constituting the thread vanish because of twist. Moreover, the rate of increase in strain differs to some extent according to twisting number, but strain is comparatively great until the tensile load is up to about 30 grams and increases gradually when the tensile load reaches 45 grams.
(2) Between the compressive load, P, and the modulus of strain, ε, an experimental formula, P=a•εOn-m•εm, is formed where a, m and n are constants defined by twist and tensile load, and εO. is the turning point of the P-ε logarithmic curve.
(3) The ratio of thickness and breadth which shows the deformation of the thread decrease as P increases. With load removed, the ratio is almost constant when P attains a cer_??_ain value.
(4) The modulus of compressive elasticity and the modulus which corresponds to recovery elasticity are capable of being calculated.
