Abstract
Today, the probabilistic model adopting Monte Carlo simulation is the established method to predict the modulus of rupture (MOR) of glued-laminated beams.
However, it would be significant to calculate the MOR by another numerical analytical method. Therefore, we propose in this paper an elasto-plastic analytical method to predict the bending properties of glued-laminated timber beams.
The method is the application of the Rigid Bodies-Spring Model (RBSM). Load-deflection curves, proportional-limit bending stresses (σp) and MOR of glued-laminated beams were analyzed using the following assumptions.
1) Glued-laminated beams were assumed to be multi-layered beams.
2) Stiffness equations for simple beams were applied to the spring elements parallel to the longitudinal direction of the beams. Stiffness equations for two-dimensional plane-stress problems were applied to the spring elements perpendicular to the longitudinal direction.
3) A quadratic formula considering bending moment and axial force was adopted as the failure criterion of the beams.
To verify the validity of the present expression, the calculated σp and MOR of glulam beams were compared with previous results. A good correlation was demonstrated between the predictions of our theoretical model and experimental and calculated ones obtained by other researchers. Consequently, the analytical method based on the RBSM proposed in this study has been shown to be valid.
