The Span Military Beam Truss Arch Stress Analysis Of The Construction Phase And Of The Performance

Military beam truss arch structure is the geometry of the spatial structure, which is connected by a series of the standard triangular truss, and it belongs to the space bar structure. It is widely used in practical engineering, and it is important structure geometry of the future direction. With the technical progress of design and construction, truss structures become larger fly-past and more flexible, which brings up more strict requirement for the structural stability. Consequently, practical theoretical analyses and numerical approaches become more important.In this paper, the military beam truss arch structure of long tan Valley 1 # bridge is taken as an object to the research of static analysis, modal analysis, stability analysis and optimization design. The main discusses are followed:1) Load behaviors of the military beam truss arch structure under different load combinations are calculated by the finite element software, inner force distribution and point displacement are obtained, and then static performance is known. And the pre-arch of the major joint of the military beam truss arch structure under different load combinations are calculated and analyzed.2) Modal analysis for this military beam truss arch structure is carried out, and natural vibration frequency and modes are obtained. Modal analysis is also called the superposition method of dynamic analysis, and it is the most effective and commonest approach of the linear structural seismic analysis. The results indicated that, the base frequency of military beam truss arch structure is relative taller, this explains the truss arch structure stiffness is better; the frequency distribution is close, the participation of the higher-order vibration modes should be considered in seismic design course. The model of the military beam truss arch structure is mainly the vertical and horizontal model, and it is accompanied by torsion and local vibration of the evil league strikeout model.3) In view of the fact that the rigidity of military beam truss arch structure has major characteristic, in order to make military beam truss arch structure more reasonable and economical, the military beam truss arch structure is carried out the optimized design. The minimum total mass of military beam truss arch structure is considered as objective function, and strength, rigidity, and stability of members are considered as restrain conditions, and after eight times iterative optimization, the better economic structure component section size are selected.4) Based on static analysis of the military beam truss arch structure, linear buckling and geometric nonlinear stability have been investigated by allowing for the perfect and imperfect structure. The relation curves of load-displacement of the military beam truss arch structure are obtained.