Research On Latticed-Shell Structure's Stability Based On Surveyed-On-Plot Imperfection And Some Correlative Problems

Latticed-shell structure has the characteristic of handsome architectural form and excellent bearing porfermance at the same time, but how to predict precisely its bucklingloads with the affection of primary imperfection being considered is still a very outstanding problem. When it was researched before with stochastic imperfection modal method, primary geometric imperfection of latticed-shell structure which is taken as stochastic importing variables was often assumed to obey Guass Distribution with all variables independent to each other, and standard deviation was assumed to equal to half imperfection breadth. If these presuppositions are reasonable is not verified by any theory or any experimentation yet.Pointing to this problem, firstly, after the data of coordinate excursion, which is of nodes of experimental model and practical structure and was surveyed on plot, is utilized in an innovative way and analyzed statistically and systematically, disciplinary conclusion about the stochastic distribution manner and statistic parameters of latticed-shell structure's geometric imperfection is obtained. Secondly, on the base of the statistic analysis results of the surveyed-on-plot data, stochastic imperfection modal method based on surveyed-on-plot imperfection, which has its own characteristic, is put forward. Then, the analysis of bucklingloads of two experiment models validates the method's dependability and superiority by comparing with experimental result and that of literature [1]. According to the parameter-analysis whose parameters are correlation coefficient, diversion coefficient, etc. of stochastic imperfection, some qualitative even quantificational conclusion is also achieved to guide practical engineering.Any method or technology has the necessity to be optimized or even to be innovated. Pointing to the issue of how to tail nonlinear fork curve and acting on the thought to innovate, method of disturbance at vice-fork point is put forward based on the primary research achievement in this field of Space Structure & Form Institution of Southeast University, which provides conditions for the similar research combining consistent imperfection modal method and this one.Deficiency of consistent imperfection modal method, which is also a way aimed to get Latticed-shell structure's bearingloads, is discussed as well, and stochastic imperfection modal method considering affection of geometric nonlinear and physical nonlinear is recommended to verify the result of latticed-shell structure's bucklingloads calculated with the method prescripted in literature [11].