Micro-mechanical modeling of irreversible hygroscopic strain in paper sheets exposed to moisture cycles

Paper is a complex material consisting of network cellulose fibres at the micro-level. During manufacturing, dried under restraint conditions due to tension in paper web machine direction. This gives rise internal strains that are stored produced sheet. Upon exposure moisture cycle, these may be released. results permanent shrinkage cause instabilities such as curl or waviness The prime objective this model irreversible and link its magnitude properties network. For purpose, randomly generated fibrous networks different coverages (i.e. ratio area occupied by sheet) modeled means periodic representative volume element (RVE). Within RVEs, finite method combined with kinematic hardening plasticity scale used capture response. computational obtained demonstrate increases coverage until certain beyond decreases magnitude. phenomenon explained considering fraction free-standing fibre segments relative bonded A structure–property dependency sheet-level on micro-structural parameters thereby established.