Analysis Of Vertical Behavior Of Plywood Beam Joints

Wood is the most commonly used building material in ancient China,which has been used to build numerous brilliant wood structure buildings.In recent years,with the rise of reinforced concrete structure,the construction of wood structure buildings is less and less.In recent years,people pay more and more attention to the huge waste of resources caused by reinforced concrete construction in the process of construction and use,and carry out optimization one after another,for example,strongly advocate the prefabricated reinforced concrete structure to reduce the generation of construction waste and environmental pollution in the process of construction.With the continuous development of society and the continuous improvement of people’s living standards,people have a better understanding of the residential environment With the increasing requirements of environment,it began to change from the initial requirements of safety,applicability and durability to the requirements of health,comfort,energy conservation and environmental protection.As a kind of building material with light weight,high strength,renewable,environmental protection and excellent seismic performance,wood has been paid more and more attention.Therefore,the research on wood structure building is of great significance for the future development of buildings.The mechanical properties of wood are not only affected by the quality of wood itself,but also directly related to the arrangement direction of wood texture.It is a typical heterogeneous natural polymer composite engineering material.Therefore,in the process of assembly of glued wood,according to the different external forces to find suitable glued wood combination,the bearing capacity of glued wood structure can be greatly improved,Expand the application field of wood structure.ABAQUS finite element method can be used to simulate the performance of wood.By establishing the finite element model of glued wood,the simulation of glued wood structure can be realized,and the mechanical performance of different glued wood structures under vertical load can be understood.In this paper,the experimental study of wood mechanical properties and ABAQUS finite element simulation method are used.The research content is divided into three partsIn the first part,the mechanical properties of wood were studied,the stress-strain relationship of glued wood structure in tension and compression was explored,and the arrangement of wood grain was deduced when the glued wood structure was subjected to different external forces.It was found that the tensile properties of wood along the grain direction were better than that of wood along the grain direction,and the compressive properties of wood along the grain radial direction were better than that ofwood along the grain direction,and the compressive properties of wood along the grain radial direction were better than that of wood along the grain direction 。 Therefore,the glued wood beam should be arranged along the grain direction along the length direction of the beam when splicing,and the transverse grain with better bearing capacity should be arranged along the height direction of the glued wood beam during the glued wood beam manufacturing process.In the second part,the stress-strain relationship of glued wood structure in tension and compression is introduced into ABAQUS finite element simulation analysis.First,the joint part is fitted and analyzed,and compared with the relevant test results of Harbin University of technology,it is found that the two are basically the same.When0kN-150 kN,the applied load and the deflection change of glued wood beam are basically linear,and the glued wood beam is judged The composite beam is in the stage of linear elasticity;when the applied load is 150kN-300 kN,with the increase of applied load,the rate of deflection change begins to obviously exceed the rate of load increase.At this time,it is judged that the composite beam enters the stage of elastic-plastic work,and the deflection change of ABAQUS finite element model in the loading stage is greater than the vertical bearing capacity test of the second engineering quality inspection station of Harbin University of technology The test results show that this phenomenon is more obvious when the applied load is more than 150 kN.When the applied load is 300 kN,the deflection of ABAQUS finite element model of glued wood beam increases about 10% compared with that of vertical bearing capacity test.In the third part,the stress-strain relationship of glued wood structure in tension and compression is introduced into the node model and optimization model of the long-span glued wood structure roof beam of Changchun national fitness swimming pool,and the results of the node analysis of the optimization model are compared with the results of the actual model analysis in many aspects.Under the vertical load,the stress in the lower tension area of the pure wood structure beam is the minimum The maximum strain of glued wood beam and I-beam is the smallest,and the maximum strain of glued wood beam and I-beam is 50.81% and 23.77% higher than that of pure wood beam;the vertical displacement of pure wood beam is the largest The vertical displacement of glued wood beams with bolt steel joints and I-steel joints is 15.42% and27.97% less than that of pure wood beams.At present,the glued wood beam with bolt steel joint has been used in the project of long-span glued wood structure roof beam of Changchun national fitness swimming pool.The glued wood beam with I-beam steel joint has formed a patent and has been authorized by the national patent office.