Finite Element Analysis For Steel-concrete Combinated And Laminated Beam

The steel-concrete composite and laminated beams can greatly ameliorate the cracking problem in the negative moment zone of composite continuous beams.Some progress has been made in experimental research on its static performance,but there are few reports on its finite element simulation.The static performance and natural vibration characteristics of the steel-concrete composite and laminated beam were studied by theoretical analysis and finite element simulation,and the results are compared with existing experiments.The main work accomplished includes the following:The basic theoretical analysis of three different forms of steel-concrete composite beams,the steel-concrete composite and laminated beams with or without vertical connection is made.The formulas for calculating the bending capacity of the steel-concrete composite and laminated beams when the lower concrete slab is under the steel beam and the formulas for calculating the section stiffness at the elastic stage are derived.Equivalent strength principle was used to convert the upper reinforced concrete slab into a material,and the conversion formula was derived.A two-dimensional modeling of a simply supported single-span steel-concrete composite and laminated beam with vertical connections was performed by using this method and ANSYS finite element software,Then the load deflection curve and the relationship between the load and the submit interface slip distribution are obtained.Compared with the experimental results,the agreement is good.The contact and separation areas of the interface between the composite and laminated beams during loading are studied,it is concluded that friction can be ignored in the negative moment area.Complete composite beams and the composite and laminated beams without vertical connections are set up to Contrast with the composite and laminated beams with vertical connections.The difference between the load deflection curves and the effect of the force ratio on the three are studied,and the influence of the proportion of span-free length in the non-vertical connection composite and laminated beam on the load deflection curve was studied.The natural vibration characteristics of three different connected single-span composite beams are studied respectively,The first five vibration figures and the natural frequency of the three modes are obtained and compared.The application of three different connection types of composite beams in continuous beams is studied.A proportional model of a two-span composite continuous test beam was modeled by the method in this paper,at the same time,a two-span finite element model of a composite and laminated beam with vertical connections and a composite and laminated beam without vertical connections are set as a comparison,The three load deflection curves calculated by the finite elements are compared with the load deflection curves of two-span continuous beams in the test.The modal of composite continuous beams with three different connection types are analyzed,and then the first four vibration figures and the natural frequency are obtained and compared.In the process of natural vibration,Without vertical connection will cause the upper and lower beams to collide and separate.And as frequency orders increase,the difference between the natural frequency of the laminated beam with a vertical connection and a laminated beam without a vertical connection is increasing,but the difference from the fully combined beam is small.