Study On Mechanical Properties Of Fast Assembled Composite Bottom Plate Hollow Composite Plate

With the serious aging of the Chinese population,the shortage of labor resources year by year,accompanied by the problems of high energy consumption and high pollution in the traditional construction process,makes the construction cost increase.In order to solve these problems,the state has introduced a series of measures to promote the development of prefabrication,to achieve the reform of building industrialization,laminated plate as one of the most important components in the prefabricated structure,after the study of relevant literature,a new type of laminated plate of fast assembly and combination of hollow laminated plate is proposed.The bottom plate of the new composite board is composed of cement fiber board and molded steel plate,which are connected by flat head drilling nails to realize quick assembly of the bottom plate.The bottom plate is arranged with hollow tubes and steel bars,which is simple and convenient for construction.The hollow tubes reduce the dead weight,and the pouring layer is finally put.In this thesis,the proposed new composite plate design test to study its bending capacity,the main work is as follows:(1)Five new composite plate specimens were designed and carried out static loading test,including one prefabricated bottom plate,three one-way plates and two two-way plates.By observing the failure morphology and process of the specimen,the stress-strain curve and load displacement curve are analyzed,and the characteristic load value is determined to study the bending performance of each specimen.The test results show that the failure form of each specimen is the same as that of the whole cast plate,and the unidirectional plate and the bidirectional plate show obvious force characteristics.The deflection of all specimens reaches 1/50 of the calculated span.Under the condition of a certain bearing capacity,it has a certain ductility.The constraints of profited steel plate on concrete strengthen the flexural bearing capacity of composite plates,and the bearing capacity of thick steel plate is increased more than that of thin steel plate.The hollow arrangement in the specimen has no obvious effect on the bearing capacity and failure mode of the composite plate.The composite plate with joint,the failure point is not at the joint and there is no cracking at the joint,the joint is stable and reliable.(2)Based on the static load experiment,the calculating method of normal section bearing capacity of unidirectional slab and the calculation method of plastic hinge line are validated.The measured values of the test are compared with the theoretical calculated values,and the experimental values are both greater than the theoretical calculated values,indicating that the new structure has improved the bearing capacity compared with the general composite plate.On the basis of the normal section bearing capacity and the plastic strand method,the calculation formula is modified,and the bearing capacity calculation method suitable for the new structure is obtained.(3)The static experiment was carried out by FEM.The steel skeleton curve in the specimen is consistent with the measured stress-strain curve,and the stress cloud is consistent with the actual failure state and crack development of the specimen,and the model has great reference value.Based on this model,the sample parameters are analyzed.The thesis consists of 57 figures,13 tables and 90 references.