Mechano-Sorptive Structural Analysis of Wood by the ABAQUS Finite Element Program

摘要

A structural analysis method for the long-term response of wooden structures ispresented in the publication. The utilization of the analysis tool requires the following three components: an effective computer (Cray X-MP); a finite element (FE-) program for non-linear analysis of structures (ABAQUS); the implementation scheme of the stress-strain relation for wood into the FE-program (subroutine UMAT). The mechanical properties of timber in its cross-sectional plane were considered homogeneous and cyclindrically orthotropic, i.e. the local effects of the annual rings were ignored. The response of wood to mechanical loading and moisture changes was modelled using three strain terms: linear elastic strain, free moisture expansion and mechano-sorptive creep, which takes the combined effect of moisture change and mechanical loading into account. Visco-elastic creep accommodated with pure mechanical loading was ignored. The use of ABAQUS for detailed stress analysis of wood is demonstrated with examples. (Copyright (c) Valtion teknillinen tutkimuskeskus (VTT) 1991.)