Geometry, mechanical factors, and strength of twisted filaments

This article presents a theory of the contact interaction of two filaments that are twisted together. A formula is obtained for the contact load, which is expressed through the tension of one filament (one component). Another formula is obtained for the strength of the twisted filament, and a weak local strength maximum is found. The conditions under which the outer filament and the axis of the twisted filament are parallel were determined analytically: 1) the twisting of the initial filament K 1 and the secondary twisting K must be done in opposite directions (the twist K 1 has a minus sign in Eq. (13)); 2) the secondary twist K must be exactly half as great as the twist for the initial filament K 1 .