Modeling Slip in Stress-Laminated Timber Bridges: Comparison of Two Finite-Element-Method Approaches and Test Values

Finite-element (FE) simulations of the deformation behavior of a 5.4-m-long, 8-m-wide, and 0.27-m-thick stress-laminated timber bridge deck were conducted. The simulation results were compared with full-scale test results when using a load resembling an axle load placed near the edge and when cycling the load between a high and low value. Two separate approaches to nonlinear FE modeling were used. The first FE model simulates a frictional slip between the glulam beams with an elastic-plastic material model. The second FE model simulates a frictional slip by modeling each discrete contact surface between each beam in the deck. The results show good agreement between simulation and test results and reveal that the simulation model that models contact surfaces produces slightly better results at the expense of a greater modeling effort and increased computational time. Hysteresis in the load versus deformation curves is clearly visible and was due to significant slip between the glulam beams, which was successfully simulated