Study On Double Slip Surface Characteristics Of Composite Beams

The double slip surface composite beam is a kind of flexural member which is made of three layers of construction materials with different mechanical properties at the interface, for example, PC composite beam with corrugated steel webs、Steel truss girder webs、carbon fiber reinforced steel and Concrete composite beam etc. As there are two interfaces, inevitably, there will be shearing slippage effect in between. It’s mechanical structure is far more complicated than the conventional combination of single sliding surface beam, unknown quantity of stress and strain increases and difficulty on solution multiplied. The accurate calculation and analysis the mechanical state is crucial to the rational design of composite beams. To better improve the design theory of double slip surface combination beams, base on the in-depth analysis of double slip surface mechanical properties of beam combination, this study will start with the example of carbon fiber-steel-concrete composite beams and perform relate research on the calculation theory of this structural form.1. After laboratory tests on 6 double slip surface composite beams, a spacial simulation analysis model of double slip surface composite beams is built up based on the ANSYS software platform, it accurately stimulated the spacial behavior subject to force and verified the validity of the model through laboratory tests.2. An elasto-plastic analytical solution of double interface slip of the simply supported composite beams under the effects of vertical loading is deduced base on the principle of elastic mechanics and contact theory. Comparative analysis with laboratory test result proves the correctness of the solution, and established accurate calculate method of static response of double slip shearing slippage composite beams under its normal state.3. Base on the matrix displacement method on structural mechanics, the finite element solution of 2 node 10 degree of freedom rods system of Double slip surface composite beam with Slip effect is generated, which eliminate the defect of inaccurate interfacial slip effect of general matrix displacement method. Through this matrix displacement method, founded with iterative method, we calculated the nonlinear beam static response with separate step and layer transformed section method. It is proved that this method can effectively analyze the nonlinear characteristics of double slip surface along with the Comparative analysis with laboratory test result.4. Base on plasticity theory, it’s able to derivate the calculate method of ultimate flexural capacity of double slip surface composite beam under two conditions, full shear and partial shear connection. Compare the calculation result with trail value, it turn out the basic plasticity theory can perform mathematical calculation on the design of flexural capacity of double slip surface composite beam.5. Based on the principle of eccentric press method, it’s able to derivate the cross section transverse distribution coefficient of the superstructure of double slip surface bridge with shearing slippage effect, provided a complete design theory for the Double slip surface composite beam bridge.