Research On Bonding Properties Of Bamboo-steel Interface Under Cyclic Loading

Steel structure system is the combination of specific fitting composites which are bambooveneer and cold bending thin-wall steel, it is a high efficiency and energy-saving buildingstructure system. It contains the advantages of both steel and bamboo, overcoming instable ofthe cold bending thin-wall steel and improving the ductility performance of the bambooveneer. In this paper there will be a research on bonding properties of bamboo-steel interfaceunder cyclic loading, contains exploring of the bond stress distribution curve, relative slipdistribution rule of the interface and the bearing capacity of the bonding interface damage rule. An analysis of the interface’s strength is provide a reliable basis for the damage forms of theseismic disturbance such as dynamic loading for the research of structure.In this paper, total of24push-out specimens has been designed to two types of interface,respectively A group of12pure bonding interface specimens and B group of12compositebonding interface specimens. First, three specimens of each group has been designed for staticload test, through the test, the bearing capacity and the strain data of the bamboo plate of thetwo kinds of interface are acquired. Based on the flat section assumption the theoryexpression of normal stress along the longitudinal, shear stress distribution, relative slipdistribution was proposed. Second, three specimens of each group has been designed for thelow cycle level load test, through the test to determine the bamboo-steel column specimens inload to the critical displacement of the linear and nonlinear stage, for the test of the repeatedload displacement. The cyclic loading test sets the type of the bonding interface, thedisplacement of the cyclic loading as basic parameters,12push-out specimens are testedunder cyclic loading test, data of the bearing capacity of specimens and the strain data of thebamboo plate are obtained, capacity and strain are compared with the short-term load tests,two groups of specimens interface bond properties change rule is acquired.Combined with experimental results and theoretical analysis, it shows that when therepeated load displacement to the specimen was in the linear phase, the initial damage isalmost not exist, its ultimate bearing capacity of basic interface was without loss, the bamboo-steel column give full play to the overall performance to the tested under cyclicloading test. The damage of composite bonding interface specimens was compared with purebonding interface specimens, the ductility of the specimen interface performance, deformationperformance and bearing capacity were significantly improved. when the repeated loaddisplacement to the specimen was in a nonlinear phase, it was been in the stage of yield,there would been a different degree of initial damage. The ultimate bearing capacity of basicinterface are significant reduction compared with the short-term load tests, through theanalysis of classic damage model, the damage evolution of bamboo-steel column under cyclicloading test was proposed.