Study On The Performance Of A New Type Pre-stress Cable-single-layer Cylindrical Reticulated Shell Structure

According to the approximate characteristics of internal force distribution and deformation that the transverse arch beams of single-layer cylindrical reticulated shell structure have, comparing with the behavior of wide-span plane circular arch beam ,when they are subjected to the uniformly distributed vertical load, this paper introduces a reinforced method the same as a new type plane cable-arch structure into spatial shell structure to present a new kind of pre-stress cable—single-layer cylindrical reticulated shell system. The new type structure is constructed by arranging proper stay-bars and prestress cables in the inside and outside of shell curved surface along the axis of the transverse arch beam based on initial single-layer cylindrical lattice shell in order to improve its mechanical behavior, increase its stiffness and bearing capacity.The main content in this paper are as follows:(1)Conformming to existing regulations, the author has designed the new type pre-stress cable—single-layer cylindrical reticulated shell structure elementarily under the condition of the most disadvantageous resting loads, put forward a complete set of design measure about it , calculated the new type structure's internal force and node displacement under the conditions of different load combination forms, and made certain the structure's main control index in its design.(2) The finite element analysis software ANSYS has been adopted to analyze the new type structure's mechanical behavior with the variety of different initial prestress value,the ratio of rise to span, the length of stay-bars, the sectional area of cable,the prestress ratio of mid cable system and zygomorphic cable system under the condition of different vertical loads and sum up the variety rules of maximum internal force and node displacement given invariable structure parameters, contrasted with single-diagonal bracing single-layer cylindrical lattice shell. The conclusion show that the new type structure has obvious superiority and its stiffness and bearing capacity enhance more greatly.(3) In order to determine the critical load and buckling shape of new type pre-stress cable—single-layer cylindrical reticulated shell structure from stable balance to unstable balance condition, the combined finite element model of beam elements,stay-bar elements and cable elements is established adopting the finite element analysis program ANSYS to make the eiginvalue buckling analysis on them by means of Lanczos method, and to make the nonlinear buckling analysis of initial defects by means of Newton-Rphson method and arc-length method. Through changing structural parameter and geometric parameter such as the ratio of rise to span, span, initial prestress, the length of stay-bars, the sectional area of cable, etc., the author systematically studied the elastic stability behavior and variety rules under the condition of different vertical loads. The conclusion show that the new type structure's stability bearing capacity enhance more greatly contrasted with single-diagonal bracing single-layer cylindrical lattice shell structure, and we can obtain rational range of some structural parameter.