Engineering Geology

Engineering Geology

Behavioral Properties of Hardness, Ultimate Capacity and Ductility of a new Semi-Rigid Connection

Author
H H.Lavasani
Abstract
With regard to the increase of computing power in the past decades, finite element methods have been used to obtain the graphs of rotational moment curves which reflect non-linear effect in connections response. Several common semi-rigid connections are modeled and their behavioral properties are briefly reviewed, then the details related to a new semi-fixed connection have been provided. The behavioral properties like hardness, ultimate capacity and ductility are investigated and compared to other simulated connections. To perform non-linear analyses of connection, finite element software ABAQUS is used. In this simulation, it has been tried to have inter-component interactions according to reality as much as possible. Bolted connections are modeled exactly and the interaction among the bolt surface and hole is modeled as a hard friction with friction coefficient 0.3 with the ability of separating after loading. Also, fillet welds are modeled as a prism with triangular section. Where a groove weld is applied, since the strength in this type of welding is like base metal, two connection parts are stuck together. To mesh the element, C3D8R element is used. The proposed connection n1 has the most rigidity values among semi-rigid connections. Reducing the number of connection bolts has more reducing impact on connection rigidity value, so that with the half thickness of upper and lower sheets, rigidity rate is reduced only 9%, but with the half number of bolts, rigidity rate is reduced about 64%. Also the connection n3 have lowest rigidity rate and its rigidity amount is in the class of bolted connection in seat angle to web angle.
Keywords
semi-rigid connection
finite element method
connection hardness
ultimate capacity
1. Johnson B., Green L., "Flexible welded angle connections", AWS. Weld Journal Vol. 19(10) (1940) 402-408.
2. Frye M.J., Morris G.A., "Analysis of flexibly connected steel frames", Canadian Journal of Civil Engineering, Vol. 2(3) (1975) 280-291.
3. Richard R.M., Abbott B.J., "Versatile Elastic-Plastic Stress-Strain Formula", Journal of Engineering Mechanics, Vol.101 (EM4) (1975) 511-515.
4. Ang K.M., Morris G.A., "Analysis of Three-Dimensional Frames with Flexible Beam-Column Connections", Canadian Journal of Civil Engineering CSCE, Vol.11 (1984) 245-254.
5. Lui E.M., Chen W.F., "Analysis and behaviour of flexibly-jointed frames", Engineering Structures, Vol 8 (2) (1986) 107-118.
6. Kishi N., Chen W.F., "Moment-rotation relation of top and seat angle with double web angle connections", Connection in steel structures, behavior strength and design. E.A.S. Publishers, London, England (1988) 121-134.
7. De Stefano M., De Luca A., "Modeling of cyclic moment-rotation response of double-angle connections", Journal of Structural Engineering, Vol.120 (1) (1994) 212-229.
8. Shen J., Astaneh-Asl A., "Hysteresis model of bolted-angle connections", Journal of Constructional Steel Research, Vol.54 (3) (2000) 317-343.
9. Chaboche J.L., "Constitutive equations for cyclic plasticity and cyclic viscoplasticity", Int.J.Plast, Vol.5 (3) (1989) 247-302.
10. Chi W.M., Kanvinde A., Deirelin G., "Prediction of Ductile Fracture in Welding C onnection using the SMCS Criterion", J.Struct, Eng, 132 (2) (2006) 171-181.
11. Krawinkler H., Gupta A., Medina R., Luco N., "Loading histories for Seismic Performance Testing of SMRF Components and Assemblies", SAC Joint Venture, Report no.SAC/BD-00/10.Richmond (CA) (2000).
12. American Institute of Steel Construction (AISC), "Specification for Structural Steel Buildings", Chicago, IL, American Institute of Steel Construction (AISC), Inc. (2005).
13. Ste Fano M.D., Antonell D.L., "Mechanical Models for Semi rigid Connections", In Constrtional Steel Design, Ed., P.J., Dowling, J.E., Hardening, E.Martinez-Romero, Elsevier Applied Science Publishers, London (1992) 276-279.