| I-section of steel arches with web openings have been used more in practical engineering in recent years.As a new type of structure,its beautiful appearance,high structural load-bearing efficiency,and convenient use of pipelines for building functions.It has been popular with engineering designers in recent years.The stability of steel arches has always been difficult in design.Therefore,a more extensive study of the stability of steel arches is needed to ensure the reliability of the design.However,due to the characteristics of the steel arch members with web openings,there are some problems in the stability,which need to be further studied.The main tasks completed in this article are as follows:(1)The in-plane buckling equilibrium differential equation was established based on the principle of energy virtual work,and the expression of elastic buckling load in the plane of the steel arch was derived.Two hypotheses in classical theory of web steel arch in-plane were discussed,and the theory was proved.The elastic buckling coefficient K is related to the geometric slenderness ratio ? and the vector span ratio m.(2)When the board is simply supported by two loading edges and the non-loading edges are fixed.Compressed elastic buckling coefficient of the web is obtained.Based on the elastic buckling of solid webs,the finite element numerical simulation was used to study the influence of radius and distance on the elastic buckling load of plates.The reduction coefficient is introduced.The influence of radius and distance is considered to obtain the elastic buckling coefficient of the holes plate under compression.(3)The elastic buckling mode of the steel arches is obtained through the analysis of elastic buckling.The elastic buckling mode of the steel arches is divided into two types: overall antisymmetric instability in-plane and local buckling instability.The geometric slenderness ratio and the web thickness both an influence on the elastic buckling morphology.By establishing a holes optimization function,the elastic buckling analysis of the hole when considering web buckling is performed to obtain the recommended value for holes optimization.(4)Through elasto-plastic analysis,the difference between the failure mechanism of when considering web buckling and the failure mechanism of overall buckling steel arch is studied.It is found that the web buckling has a significant reduction effect on stability.Moreover,the damage form of the steel arch changed from the overall instability to the related failure form.The geometric factors such as geometric slenderness ratio,sagittal span ratio,web height-thickness ratio,flange web thickness ratio,and flange widththickness ratio were studied under different load conditions on the bearing capacity of steel arches considering local buckling of web.(5)Proposed design formula for steel arches under pure compression and bending.When the flange web thickness ratio is 4,the parameter regularized web height-thickness ratio is introduced.The influence of web buckling is taken into account.The reduction coefficient is introduced.The formula for the stability coefficient of the steel arch under pure compression is proposed through numerical simulation.In order to unify the formula form,the equivalent coefficient is introduced to obtain the expression of the stability coefficient when the flange web thickness ratio is not equal to 4.Based on pure compression condition,the straight member beam and column are compared to obtain the compression and bending effecting suggested design formula.(6)Elastic buckling analysis of an open-hole steel arches with out-of-plane support when considering web buckling.Analyze the buckling mode with a single support,compare similarities and differences between the buckling mode of steel arches when the web is buckling,and consider only the buckling mode of the overall buckling steel arch.The effect of the support position,number,and geometric parameters on the stiffness of the elastic threshold is studied. |
PDF Full Text Request