Study On The Design And Stability Of Double-layer Latticed Shell Structure Upper Large-span Bunker

With the development of socioeconomic, large-span latticed shell structuresare widely used in industrial and civil architecture. Latticed shell structurespossess high stiffness, light weight and models with rich esthetics features.However, with the current trend of the shell structures having larger span anddecreasing thickness and weight, its structural stability has become a major focusof research.This paper takes the double-layer latticed shell upper coal bunker of powerplants for computational analysis using finite element software ANSYS. Analysison the latticed shell structure’s linear and nonlinear buckling property isperformed from three aspects of structural member selection, buckling propertyand temperature effect. During this analysis, a study is done on the respectiveeffects of nonlinearity, support restraint conditions, initial defect and load distribu-tion on the structures ultimate bearing capacity.The research shows that: The magnitude of the horizontal support reaction ismainly controlled by the wind and temperature load; For member selection, thetype of support is the deciding factor; The effect of supports on the coefficient ofstructural stability is dependent on the supports rigidity; Simplifying the supportrestraint as fixed supports tends to be safe; Initial defect reduces the ultimatebearing capacity, it’s appropriate value should be selected within the rangeL/300~L/200; The stability of the structure under horizontal loads is inferior tothat under vertical loads, their coefficients of stability differ by54.4%; Thebuckling load factor for half span loading exceeds that of full span loading by30%; At normal atmospheric temperature, the effect of temperature variations onstructural stability is very small, however, the temperature effect on the structuralmembers internal force especially of the lower deck members is a must consider;For double-layer latticed shell structure, the external environment temperature hasa big effect on the structural internal force, and the inside temperature plays animportant role in the structural deformation; When the temperature reaches100°C,the structure buckles at the peak, then when the temperature reaches115°C, thestructure will get damaged, thus it can be seen that once temperature exceeds thecritical value, in a short time the structure can undergo possible destruction due tothe temperature rise. The research considers latticed shell structure optimization design as itsobjective, comprehensive consideration of the effect of support restraint conditionon stability is one of this research innovations; Cases of the coal pile inside thebunker undergoing spontaneous combustion has been considered as provided inthe relevant codes for steel structure fire protection in related calculation. In linewith practical condition, the consideration of the influence of internal and externaltemperature differences on the structural members mechanical behavior is thispaper’s another innovation.