Early Experiences in Using Multibody Dynamics Software to Simulate Flexible Webs in Production

The production of products and packaging that are based on flexible web material is a substantial industry. While there is a wide assortment of products, manufacturers share the goals of maximizing the production rate (maximum web velocity), maintaining precise control of the web and maximizing the tolerance of the production line to variability in the web. The use of simulation to achieve these goals has been limited due to the complexity of characterizing a flexible body going through geometrically-nonlinear deformation as well as making contact with rollers and guides. Instead, physical test and the knowledge of experts are used to optimize the production lines. However, the detailed understanding of web behavior is limited since it is difficult to add instrumentation to a flexible web undergoing contact on both sides. Nonlinear FEA software can be used to study the web but the run times for a web moving though a reasonable motion can be extremely long. The use of commercial, off-the-shelf, multibody dynamics software offers hope for detailed results with shorter run times. This paper describes the use of multibody dynamics software to simulate web behavior, including the development of correct input conditions and the specification of outputs of interest to the web-handling community. Two examples are shown: a web response to roller misalignment and a study of trough formation.Copyright © 2009 by ASME