Влияние крутки капроновой комплексной нити на величину ее изгибной жесткости

Abstract

For complex threads consisting of separate elementary fibers connected by means of a twist, the definition of bending rigidity is quite difficult. The integrated thread cross section represents a combination of sections of elementary fibers, between which friction forces are created when the thread is crashed. The magnitude of these forces increases from the periphery to the center of the thread, which is due to the summation of the normal pressures of the outer fibers to the internal. When bending, part of the elementary fibers located above the neutral axis of the cross section of the thread is stretched, and the axis below is compressed. If we assume that the thread curren is minimal, therefore, the friction force between the fibers is minor. When the cross section of the elementary fibers under the action of the equal forces caused by stretching or compression of the fibers, strive to settle on the neutral axis of the thread cross section. The moment of inertia will be minimal. When the thread curve tends to the maximum value at which its destruction occurs, we can assume that the friction forces between the elementary fibers will be maximal. Even with a strong bending thread, the sections of the elementary fibers will not move in the direction of the neutral axis. Therefore, the structure of the thread will be maximally sealed and the cross section can be considered a solid body having a circle form.