Research On Fire-Resistance Of Cooperative Grids With Prestressed Cablechord Members Structure Under Fire Condition

Cooperative grid with pre-stressed cable-chord members structure is a new-type hybrid spacial structure whose lower chords are replaced by pre-stressed cables. It is widely used in the buildings of store and school, which have condensed human in long time. If the cooperative grid with pre-stressed cable-chord members structure collapsed in fire before people leave safely,it will cause enormous casualties and loss of properties.But present the study of it mostly focus on its static and dynamic properties.so,it is necessary to make a profound study on fire resistance of cooperative grid with pre-stressed cable-chord members structure.Firstly, about the simulation of the temperature field in fire, utilize the curves of standard temperature (ISO-834) and the fire temperature ascending in large space to simulate the temperature filed separately. Obtaining temperature curve of thecomponent by using MATLAB, taking into account the high temperature creep of prestressed cable, then added the temperature filed to the structure, at last analyse the result by means of thermal-structural coupled-field in ANSYS. It is destroyed at about 12.6 minutes when use the curve of standard temperature, as well as it was not destroyed even at 60 minutes when we used the curve of the fire temperature ascending in large space.Also study the displacement of the middle span and the internal force vary with time.high-time creep has little affection on the response of the structure. The real responds of structure under fire can be shown more veraciously by using the curve of the fire temperature ascending in large space.Secondly,discussing the impact parameters of the structure under the curve of the fire temperature ascending in large space, such as span, high-to-span ratio, node load, bearing conditions and the initial prestress. Also taking into account the influence of fire location and the fie protection. The disciplinarian of the structural internal forces and displacements was also summarized, and reasonable design parameters are gotten.All of which aim to provide references to design.Finally,cooperative grid with pre-stressed cable-chord members structure is compared with the common grid structure under fire condition .by using the curve of the fire temperature ascending in large space for an hour ,they have similar reaction , however, the common grid structure has larger deformation.In summary, aiming at cooperative grid with pre-stressed cable-chord members structure, using two typical indoor curves of the fie temperature ascending to analysis the response of anti-fire.The fire resistance of cooperative grid with pre-stressed cable-chord members structure and its influence factors are possessed ,which can be used to guide practical projects.