Influence Analysis Of Lattice Shell Structure Based On Measured Imperfection

As the rapid development recent years, lattice shell structure is widly used in struncture engineering.Especially,steel lattice shell attain its popularity because of its distinguish structure form and marits.Ultimate load capacity analysis is one of the key technology of steel-lattice shell. The factors influencing the ultimate load capictiy are random. The ordinary code can not take the random factors into consideration. Along with the structure stochastic finite element theory development and the increase of the number of statistical data, can be in on the net shell structure design and production, introduced stochastic defect mode method, to the concept of the Angle of probability to ensure the stability of the structure performance and ultimate bearing capacity.Based on the three practical grid structure engineering, and select the commonly used four section rods, counted 800 measured defect data (material yield strength, steel pipe wall, steel pipe diameter), use probability statistics theory and methods, eliminate the abnormal data, establish the structure of steel rods used section pipe wall, diameter and materials in the strength of the defects of the random distribution parameters and statistical information. On this basis, based on stochastic finite element theory, with the aid of analysis software, using modal method and consistent defects random defects modal method, this article discussed and studied in different rise-span ratios in the roof of the net shell structure uniformly distributed load, cloth uneven loads, the ideal, initial geometric imperfection is L/1000, the rods defects and defect to the structure stress mechanism and the influence degree of analysis. Analysis shows that, the rods section positive and negative error distribution in random, artificial reduce wall thickness, diameter of defects such as influence of the structure of can not be ignored.