Characterisation of moisture-dependent plasticity of beech wood and its application to a multi-surface plasticity model

Abstract The moisture-dependent stress-strain behaviour of European beech wood (Fagus sylvatica L.) has been determined under compression, analytically described for the radial and tangential direction using a modified Ramberg-Osgood approach and realized numerically by a multi-surface plasticity model. The conspicuous decrease of the stress-strain characteristic perpendicular to the grain with increasing moisture content is similar to the behaviour of the presented ultimate strength values in the longitudinal direction. Based on input parameters previously quantified by means of an inverse finite element analysis, the simulation of a crosswise laminated two-layer arrangement during moistening was carried out. A distinct development of plastified regions can be observed due to the resulting swelling stresses.