Stability Analysis Of Concrete Herringbone Folded-plate Reticulated Shell Structure

The introduction of concrete herringbone ribbed pleated lattice shells enriches the structural form of the concrete shell structure,which combines regional humanistic characteristics,local economic development and local climate conditions.As long as the structural form is mainly herringbone,the main application is in the roof of the structure.The engineering practice shows that it can be well applied to medium and small span public buildings such as teaching buildings and auditoriums.The main material is concrete,which can greatly reduce the amount of steel bars and can be used at the same time.Effectively solve the corrosion problems caused by weather and other conditions of steel structures in engineering applications,fire resistance and durability are good,while the structure has a natural drainage function,fitting the country’s vigorously promoted green building concept.For the concrete structure,the length of the structural members,the error of the crosssection dimensions and the displacement of the nodal coordinates caused by the support of the mold,the local collapse caused by the displacement of the scaffold,the displacement of the rebar tying,and the failure of the mold and the pouring of the concrete during pouring.The weakening of the cross-section of the honeycomb plywood and the ribs caused by corrosion of the steel bar are common phenomena.These adverse phenomena will affect the static or seismic bearing capacity of the concrete structure and affect the stable bearing capacity of the space structure of the concrete.For the space structure,among the many unfavorable factors,sometimes the initial defects due to dimensional errors have an irreversible effect on the structural stability of the bearing capacity.The herringbone ribbed pleated plate reticulated shell has a small section size of the components,so this The effect of these initial defects on the stability of the structure is particularly important.It may sometimes become an important issue in controlling the ultimate bearing capacity of the structure.At the present stage,the stability analysis of the concrete folding plate reticulated shell is relatively small,and the herringbone folded plate reticulated shell is the roof of the new concrete structure engineering application.The stability analysis of the structure is indispensable.This article mainly discusses the concrete herringbone folding.The elastic stage of the structural structure of the plate net shell and the non-linear phase stability energy introduced by using the defect mode method to introduce the defect show that:The cross-sectional ratio of the structure and the rib stiffness are the main factors affecting the critical load of the structural elastic instability.The span ratio of the roof and the critical load have a linear relationship.With the increase of the cross-span ratio,the elasticinstability load increases,and the structural arch direction increases.The more obvious the performance of force transmission.The rib is the main force and structural component of the structure.The critical load of the elastic instability will increase with the increase of the rib stiffness.Therefore,the rib stiffness of the structure is the main measure to increase the structural instability load.The structural ribs are lapped on the ridge line.It can be seen from the structural instability mode that the unstable mode is symmetrical about the ridge line.The ridge line can be considered as the directional sliding bearing edge of the ribbed plate,and the ridge stiffness increases.There is no significant effect on the critical load of the structure.The side beam as the main force transmission member of the structure,the increase of the bending stiffness can not increase the critical load of the structure,so the increase of the stiffness of the side beam is not the main measure to increase the critical load of the structural elastic stage.Only changing the thickness of the structural roof has little effect on the critical load of the structure.Therefore,it is recommended that the smaller thickness of the structure can effectively reduce the weight of the structure if the structure meets the requirements.The first-order buckling mode of the structure is introduced as the initial defect of the structure as the structural nonlinear stability analysis.The influence of the stiffness of the structural member on the ultimate load of the structure is discussed.The results show that the span ratio and the rib stiffness of the structure are the structural ultimate loads.The main factor.The ultimate load of the structure increases almost linearly with the increase of the span ratio.When the span ratio is less than 1/6,the influence of the increase of the rib stiffness on the ultimate load of the structure weakens.According to the analysis of the dynamic characteristics of the structure,it is recommended that the span ratio of the structure is less than 1 /6.The increase of the rib stiffness can obviously improve the overall stiffness of the structure,and has a significant effect on the ultimate load of the structure.When the ratio of the span span is constant,the method of increasing the structural ultimate load can be used to increase the rigidity of the structural ribs.From the process of structural instability,it can be seen that the structural deformation develops from the rib to the ridge,and the increase in the stiffness of the ridge can increase the ultimate bearing capacity of the structure to some extent.Increasing the bending and torsional stiffness of the structural beam by increasing its height and width does not significantly increase the ultimate bearing capacity of the structure.In the analysis,the addition of the comparison of the structure without plate roof can see whether the plate has an effect on the ultimate bearing capacity of the structure,but the thickness of the roof plate has no significant effect on the ultimate bearing capacity of the structure.In this paper,the influence of the structural component failure on the ultimate load is discussed.Through comparative analysis,the structural ridge and bottom chord failure hasa great influence on the structure.In the design,the ridge and bottom chord stiffness of the structure should be guaranteed.Through structural stability analysis,it is found that when the structure reaches the ultimate bearing capacity,the displacement of the maximum point of structural deformation has far exceeded the maximum allowable deflection of the structure,so for the herringbone flap type lattice shell structure,the structural stability performance is not the structure Design considerations.According to the structural stability analysis,the calculation formula of the bearing capacity is fitted,and the bearing capacity of the structure can be well reflected according to the inspection analysis.It is hoped that it can provide reference for the structure application.