| In order to promote the development of prefabricated buildings and to promote the composite slab with no bars in all sides,we encourage the use of dense joint separation between the prefabricated composite slab of steel truss,and arrange additional steel mesh at the same time.However,the effect of the cancellation of "beard bars" on the mechanical properties of composite beams is not clear yet.The embedded Angle steel connector in the prefabricated composite bottom plate of steel truss is a new type of connection with steel beam.It is of great significance to study the mechanical properties of composite beams with this connection.In order to analyze the mechanical difference between the two structures in the negative moment region of continuous composite beams,the monostatic static loading tests of two composite beams with composite plates were completed.The experimental phenomenon,concrete crack development,structural bearing capacity and stiffness of composite beams with composite plates are studied.ABAQUS software was used to conduct numerical simulation of the two components,and based on this,the elastic flexural stiffness of the components with different shear connection degree and the shear performance of the Angle steel connector were analyzed.The main research results include:（1）Two kinds of composite beam members are designed according to the complete shear resistance.At the same time,the material properties of each part are tested,and then the static tests are carried out on the members.The results show that compared with the structural form of embedded Angle steel joints,the reinforcement structure strengthens the integrity of members,increases the cracking load of concrete,and reduces the crack spacing.The embedded Angle steel connector improves the flexural stiffness of the member and increases the longitudinal cracking load.The ultimate bearing capacity of the two structures is almost the same.（2）The theoretical results of the calculation model for the bearing capacity and reduction stiffness of steel-concrete composite beams are almost consistent with the experimental results,so the calculation model is suitable for steel-concrete composite beams with composite plates.At the same time,it is proved that the embedded Angle steel connector can improve the elastic flexural stiffness of the member,and it is found that the Angle steel connector can share the longitudinal shear force between the steel beam and concrete,and which indirectly affects the shear connection degree of the bolt,so that the actual value of the shear connection degree is higher than the specification value.（3）By comparing finite element results of the two components with the actual results and formual computing results obtained by software ABAQUS,it is found that the three results were brodly consistent.Based on the reliable simulation results of the experimental model,the components with different numbers of bolts and Angle steel connectors were designed,and the mechanical properties of the composite beams with composite plates were analyzed.The simulation results show that compared with the composite beams without rebar and without Angle steel connection,the rebar structure has less influence on cracking load and elastic flexural stiffness.At the same time,it is verified that the flexural stiffness is proportional to the shear connection degree,and when the shear connection degree exceeds 2,there is almost no influence on the flexural stiffness of components,and it is proved that the existence of Angle steel connector makes the real value of shear connection degree higher than the specification value.（4）The curve of shear connection-flexural stiffness of composite beams without Angle steel connectors was fitted in three sections.The linear changes of flexural stiffness were inconsistent when the shear connection was in different ranges.The actual shear connection degree and the proportion of longitudinal shear undertaken by composite composite beams with Angle steel joints were calculated by the fitting formula,and the influence of the number of Angle steel joints on the longitudinal shear between steel beams and concrete is different,and the six Angle steel joints share the most longitudinal shear.（5）The influence of the number of Angle steel connectors on the shear connection degree is nonlinear.The stiffness of Angle steel connectors with different numbers of the same number of bolts is compared and analyzed.The results show that the arrangement of 7 bolts and 6 Angle steel connectors can increase the flexural stiffness of members most.It is a reasonable way to reduce the number of bolts and increase the number of embedded Angle steel connectors.Figure 41 Table 17 Reference 71... |
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