| The cold formed structural system has many advantages including high strength,light weight,easy construction,and good seismic performance.It puts forward a reasonable plan for the future development of green buildings,the promotion of prefabricated structures,and the realization of building specialization.In order to further improve the shear resistance of the cold-formed structural system and promote the application of the structure to multiple layers.The author proposes cold-formed steel composite wall-column anti-side members.A full-scale test and finite element modeling analysis have been carried out for the various mechanical properties of the composite member.The main contents and conclusions are as follows:1.In order to explore the failure mode of the cold-formed steel composite wall-column lateral members,obtain various mechanical data reflecting its shear resistance.In this paper,four pieces of cold-formed steel composite wall-column anti-side member full-scale specimens were subjected to vertical force reciprocating loading test.The main conclusions are as follows:(1)The cold-formed steel composite wall-column anti-side members can prevent the side column from premature local buckling and cause wall damage,and further exert the shear resistance of the central wall.(2)The design of the rigid support improves the local stiffness,avoiding the sudden drop in the shear resistance of the member caused by the shear failure of the self-tapping screw of the side column.The most severely damaged area of the screw is transferred from the side column to the center column,which provides protection for the important side column structure.2.Using Opensees finite element software,referring to the test process and failure phenomena,a method for determining the parameters of double-layer plate-keel screws and defining the boundary conditions is proposed.The numerical model of the cold-formed steel composite wall-column anti-side member was established,the purpose of which was to simulate its shear resistance under reciprocating load.After the simulation results were verified by experiments,the effects of the span ratio of the connecting beam,the wall-to-wall ratio,and the height ratio of the wall under the window on the shear resistance of the cold-formed steel composite wall-column lateral members were studied.The main contents and conclusions are as follows:(1)The error between the mechanical characteristic value simulated by the model and the inflection point,trend of the hysteresis curve and the test data is small.This paper proves that the simulation method for rigid support of composite members and the definition method of composite wall-column boundary constraints are correct.(2)The contribution of the upper wall of the opening of the conventional size to the shear strength of the composite member is classified and explained.3.According to the test and finite element analysis results,based on the partial shear wall design method,the coupling beam span height ratio is used as a variable,and the formula for calculating the shear capacity of the cold-formed steel composite wall-column anti-side members is proposed.Compared with the conclusion of finite element analysis,the error between the calculation result and the simulation result is small.This calculation method can be used as a method to estimate the shear bearing capacity of the cold-formed steel composite wall-column lateral members. |
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