| Glulam is widely used in modern wood structures because of its stable mechanical properties,short construction period,flexible design and environmental protection.However,wood structure has the limitation of span,and its connection way can not be pouring like concrete structure or welding like steel structure.So finding a safe and reliable connection is an important need in the development of wood structure applications.Steel structure has the advantages of high strength,stable performance,fast construction speed and good machinability.In modern wood structure,steel plate or section steel is used as the connection of wood parts,but the bearing capacity of the joint is often lower than that of the wood parts,which is difficult to achieve the equal strong connection.Therefore,how to better connect the section steel and glulam,improve the bearing capacity of the joint and avoid the premature failure or damage of the joint is still an urgent problem to be solved in the current research of glulam structure.To sum up,a new H-steel glulam beam structure is proposed in this thesis,that is,two or more sections of glulam beams are joined together by H-steel to increase their span.Compared with the traditional splint or steel plate connection,this connection method can effectively improve the bearing capacity and stiffness of the joint.For the proposed new connection method,according to the current wood structure design standards,the calculation formula of flexural load capacity of H-beam connected with glued wood beam by bolts and wood screws is established according to the yield mode of steel plywood and steel infill plate connection.And use ABAQUS finite element software to simulate the H-beam-glued wood beam connection,through analyzing the influence of bolt diameter and row spacing,the number of hexagonal head wood screws(tension zone)and arrangement on the flexural load bearing capacity of the connection node,and find an optimal connection method under the condition that the amount of glued wood beam and H-beam remains unchanged.The following conclusions were obtained from the study:(1)Under the premise that the number and arrangement of hexagonal head wood screws and the diameter of the bolts do not change,the load bearing capacity of H-beam-glued laminated wood beam will be increased accordingly as the edge distance and row distance of the bolts decrease.(2)In the case of the same arrangement of hexagonal head wood screws,increasing the number of hexagonal head wood screws,the bearing capacity of H-beam-glued timber beam will be increased.(3)In the case of the same total bolt cross-sectional area in the tension zone,the increase in bolt diameter will reduce the load carrying capacity of the H-beam-glued timber beam.(4)In the case of the same number of hexagonal head wood screws,changing the arrangement of hexagonal head wood screws has little effect on the load carrying capacity of H-beam-glued laminated timber beam.(5)The analysis results show that the bending formula of H-steel connected glulam beam established according to the standard calculation method is close to the results of finite element analysis. |
