Analysis of stress relaxation of paper tube

Roll a long paper strip into a tight tube and put it vertically on a table. Why does it often unwind in jerks? What determines the period of the jerks? In the following work, we explain the fact of why the paper tubes unwind in jerks by researching mechanical structure of paper tube theoretically and analyze the data of experiments. Finding that the basic cause of paper tube motion in jerks is stress relaxation. Successfully prove our theory by our experiments. Then we investigate the influence of several physical quantities on period of jerks, such as humidity, friction factor of paper layers. All of these factors determine the period of jerks.