Research On The Mechanical Performance Of Castellated Portal Frame Node

The current specification only brief descripts the seismic design of the cross-section portal rigid frame, not special provisions about honeycomb door frame design and construction. In terms of the present stage, the studies about cellular steel members are less and the research is not comprehensive.So the application and develop of cellular steel components in China is lag.This article summarizes the honeycomb gantry frame research status both at home and abroad, introduces the large finite element software ABAQUS and the related basic theory, according to the design and construction requirements design of finite element simulation specimens.Conside the expansion ratio(after the expansion of web height and expansion of the specimen before the web height ratio), hole distance, the node connection these three factors affect the performance of the node stress. Expansion ratio is 1.52, 1.4, 0; node connection form is flat end plate, side plate stand; hole distance(column or beam flange lateral to the distance to the center of the hole) is 370 mm and 773 mm. ABAQUS6.13 is used to establish simulated specimens. Through analysis get the following conclusions:(1) The expansion ratio effect on the properties of the specimen stress: simulated specimen expansion ratio, the greater the impact on the stress of the column flange is larger and the beam wing edge stress distribution is more uneven; the big of the expansion ratio, the more the girder end in the greater force to achieve the same displacement deformation; solid-web node of the beam end deflection, beam relative angles are significantly greater than cellular node; solid-web specimen(that is the expansion ratio of zero specimens) of relatively full hysteretic curve, it is better in the aspect of energy dissipation, ductility and cellular specimens, but its ultimate bearing capacity, stiffness, as well as cellular specimen; the specimens’ expansion ratio is 1.52 of the yield load, ultimate bearing capacity better than expansion ratio is 1.4; specimens with expansion has bad ductility than not expansion specimens, specimens not being expansion have good ductility can achieve ductile fracture; strength or stiffness of cellular nodes is higher than solid-web node; the ductility of the solid-web specimens are better, with the increase of expansion ratio the specimens decrease of the ductility; specimens with small expansion has better energy dissipation.(2) The node connection effect on the properties of the specimen stress: the node connection form of honeycomb beam wing edge stress distribution effect is not obvious; end plate stand specimen node domain to make the stress concentration phenomenon have been slow; node connection form of cellular column flange stress distribution effect is not very obvious too; cellular specimen of the beam end when achieve the same deformation speciments with end plate stand have the bearing capacity better then speciments with end plate flat; specimens with end plate stand in stiffness are larger than specimens with end plate flat; specimens with end plate stand hysteretic performance obviously no good than specimens with end plate flat; end plate flat is bigger than the ductility of the specimens with end plate stand; end plate flat in the aspect of energy dissipation is superior to end plate stand.(3) The opening distance effects on the properties of the specimens stress: opening distance has great influence on the stress of the honeycomb beam wing edge, the web hole can effectively offshoring component’ plastic hinge, to prevent the occurrence of plastic parts in the node domain; if cellular beam hole distance is reasonable, it can effectively alleviate the stress at the root of cellular components, its ductility can be effectively improved, the location of the maximum stress appears on the specimens can be controlled by changing the position of the hole; hole distance influences honeycomb column flange stress; as distance of hole center distance node domain increases the ductility of the specimens obvious increases, energy dissipation and seismic capacity are also increase; cellular specimens with the increase of hole distance are the shorter the elastic stress stage; hole distance is 773 mm of the ultimate load of the specimens is greater than the hole distance is 390 mm, is also greater than the limit load of solid-web specimen; big hole distance is bigger than the equivalent stiffness of the specimens of small hole distance; specimens of ductility and energy dissipation capacity with the increase of hole distance are become bigger.