Experimental Study and Finite Element Simulation Analysis of the Bending Properties of Cross-Laminated Timber (CLT) Two-Way Plates.

Cross-laminated timber (CLT) plates are new components in modern wooden building structures and have good integrity, stability, and high strength. However, the bending performance of CLT plate is affected by the stacking method of laminates. This study adopted two different stacking methods (three-layer cross and four-layer cross) to make four CLT two-way slabs by using Larix gmelinii slab and polyurethane structural adhesive as raw materials. The slabs were divided into two groups to reveal the effects of stacking method on the bending performance of CLT two-way plates. A jack was used to apply concentrated load on a single point of the middle span of slabs, and the strain, deflection, and ultimate load data were measured. The crack development and failure mode were observed. The ultimate failure characteristics and failure mechanism were discussed, and the finite element model of CLT two-way slab was established using structural analysis software. The influence of elastic-plastic and plywood layers on the bending properties of CLT two-way slab was analyzed, and the results were compared with the experimental results. Results show that the failure modes of CLT two-way slabs are mainly from the transverse grain tensile failure of the slab bottom, and the bearing capacity decreases rapidly when the load reaches to approximately 80% of the ultimate load. For the same thickness of CLT plate, the flexural capacity of four-layer plate is increased by 14.08%, and the elastic bending stiffness is increased by 13.63% compared with three-layer plate. The overall bearing capacity and flexural stiffness of a two-way CLT slab with the same thickness can be improved by increasing the number of laminates when four sides are simply supported. The optimal number of laminates is five. The result of finite element simulation aligns with the test, showing that the test results and analysis are reliable. This study can provide references for future engineering design. [ABSTRACT FROM AUTHOR]