Research On Bond Property Of Steel-bamboo Interface Under Statoc Loads

Steel-bamboo composite structure system is a new type of architectural form, which has outstandingadvantages of light weight, high strength, energy-saving and environmental protection, and its components usecold-formed steel and bamboo plywood as the main material, which are combined by structural adhesive.However, how to ensure the cold-formed steel and bamboo plywood to play an integral mechanical behavior ofbearing loads, is an important technology to evaluate rationality of this structure.Structural adhesive serving as bonding material which can transfer loads between steel and bamboo plywood,its shear-bearing capacity is better than other capacities in comparison, so this capacity is usually employed in thepractical engineering. From this angle, make a related study on shearing-bearing capacity of adhesive.The experiments include two parts: the double-lap-shear test and the push-out test. Main purpose of thedouble-lap-shear test is to measure the glue-joint strength of bamboo plywood and steel, and is used to predict theinterface strength of push-out specimens. By the push-out test, get a distribution rule of the shear bonding stressthat is larger in ends and smaller in the middle and is asymmetric. By comparison, draw a conclusion that thedistribution of shear bonding stress is related with length of interface and combination characteristics. From thetest results, interface failure and longitudinal failure of bamboo plywood under shear and pressure is the mainfailure forms. To evaluate the bond property can not only pay attention to its bearing capacity, but also the degreeof the shear stress concentration. Besides that, sandblasting to the interface of steel and arranging self-tappingscrews along the interface can improve the bonding shear strength obviously and bring good ductility to theinterface layer, but also make a conversion from interface failure to longitudinal failure of bamboo plywood.Establish a two-dimensional mechanical model to analysis the shear stress, considering the effect of pressure,shear and bending, and make use of complete geometrical equations and constitutive relations, to derive thedistribution equations of the shear stress and normal stress, which can strictly meet the free boundary condition ofadhesive layer.Simulate the mechanical behavior of2specimens by ANSYS10.0, in the process of which mesh the steelwith shell63, bamboo plywood with solid45and use three dimensional combin39to simulate the effects of theadhesive. Results show that the distribution form of force in the longitudinal spring elements is similar to theexperimental tests, and their values can also coincide. Accordingly, the modeling method is effective andacceptable.