Study on Mechanical Properties of Glued Laminated Wood-Concrete Simply Supported Composite Beams

The Glued-laminated timber-concrete simply-supported composite beam combines the structural mechanical properties of both glued wood and concrete. The wood beam forms a whole with the concrete slab through shear connectors, thus achieving a common working effect, and is widely used in multi-story buildings as well as in wood-frame buildings. Secondly, wood structure is in line with the development concept of green building, and the development of wood structure building can reduce the impact of the construction industry on the environment, which is of great importance.To investigate the effects of load form and peg arrangement on the slip, deflection and internal forces of Glued-laminated timber-concrete simply-supported composite beam, the modeling analysis was mainly performed using Ansys software and compared with the pegs in a uniform case arrangement to verify the correctness of the model. The basic assumption is that glulam and concrete are ideal linear elastic materials and that cracking of concrete is not considered. Based on this, this paper discusses the effects of the form of loading and the way the pegs are arranged on slip, deflection and internal forces. The modeling methods are as follow: for concrete C30, solid 65 units were used for modeling, wood was modeled with solid 45 units, while pegs were modeled and analyzed with conbine 39, and the constitutive model of pegs was modeled with the SST+S type joint fitted in Lukaszewska E. And parametric analysis is performed, and the slip, deflection and internal force of the combined beam were output. And compare the analysis with the theoretical values of the glued laminated wood-concrete composite beam.The results show that although wood is an orthotropic anisotropic material, it is possible to derive the equation for the Glued-laminated timber-concrete simply-supported composite beam by taking the modulus of elasticity in the same direction as the force according to the knowledge of mechanics of materials, and by using the theoretical equation for steel-composite combination beams. And its slip distribution law is consistent with the distribution law of steel-concrete combination beam, showing the distribution law of large at the end of the beam and small in the middle. Its effective stiffness can be calculated by using the "γ" in Eurocode EN 1995-1-1, and the error is very small. In conclusion, it is possible to derive the equation of glulam-concrete composite beam slip theory by the idea of steel-concrete composite beam slip theory, and the error is about 7%. Under the condition that the area of shear diagram is equal in size, the slip and deflection of the composite beam under symmetrical concentrated load are the largest, which should be avoided as much as possible in the project. Under most conditions, the pins should be arranged in reasonable segments according to the slip diagram, which can effectively reduce the slip and deflection of the composite beam. The Ansys finite element software can correctly simulate the Glued-laminated timber-concrete simply-supported composite beam with high accuracy, which provides methods and ideas for considering materials with orthotropic anisotropy.