The Litz Energy Method Of Discrete Stiffened Trusses On Arched Corrugate Sheet Unitized Roof

Arched-corrugated metal roof, a typical cold-formed light steel structure which is provided with a lot of advantages was introduced into China in the early 1990s. However, the metal roof was too thin to bear a big lateral load directly, and many factors lead to frequently occurred accidents and losses of people and property, which including incomplete designing theories, nonstandard constructions and theoretic seriously followed behind practices, that greatly restrained the development of arched-corrugated metal roof in China. Arched corrugate sheet-truss unitized roof is a kind of reinforced structure, which means to improve the stability performance and to increase the utmost bearing ability.Bearing Performance Analysis of Arched corrugate Sheet-Truss Unitized Roofis the first master paper about taking such measure that adding arch trusses and portrait plane trusses under arched-corrugated metal roof to reinforce it in domestic, and Research in Theory and Application about Arched Corrugate Sheet-Truss Unitized Roof is based on the nonlinear deforming theory on the large deflection of thin shell to do the study and analogy calculation. As the in-depth study of the Arched Corrugate Sheet-Truss Unitized Roof and based on conclusions in pre-papers, this paper derives a new bearing capacity expression of the unitized roof, using another analyzing theory. The paper also gives out an example and shows the analyzing results and finally gets some conclusions. The details are as followed:1. Systematically reviewing domestic researches on arched-corrugated metal roof and reinforcing measures, and centralized representing researching results of the unitized roof. After comparing reinforced compositions with the theory of monolayer cylindrical net shell and reviewing the stability theory of thin shell, the paper proves how longitudinal and lateral trusses improve the stability of unitized roof from the composition and conception of the structure.2. After elaborating research results in simplified theory, the destroyed modal and computational method of the stiffening rib shell, the thin steel plate and the cylindrical shell, it is considered to simplify trusses as discretely stiffened rib. Geometric equation of large deflection, balance equation of buckling and expressions of strain energy and general potential energy can be written out. Based on the Litz energy variation method, the paper also infers the utmost bearing capacity expression of the cylindrical thin shell with sparse and discrete stiffening ribs. 3. Using MATLAB to confirm and calculate the assigned parameter of the unitized roof and the bearing capacity expression; Comparing and analyzing the result of this paper with answers getting from ANSYS finite element simulation and the theory of rigidity equal division. and comparing the extreme bearing capacity of the unitized roof with different number of stiffened trusses, finally getting some beneficial conclusions, which establishing an foundation for further research in reinforced the arched corrugate metal roof.