NEHRP Clearinghouse
- Title
- Behavior of Pre-Northridge Moment Resisting Steel Connections.
- File
- PB96143177.pdf
- Author(s)
- Yang, T. S.; Popov, E. P.
- Source
- National Science Foundation, Arlington, VA.; American Inst. of Steel Construction, Chicago, IL., August 1995, 74 p.
- Identifying Number(s)
- UCB/EERC-95/08
- Abstract
- The basic reasons for the fracture that occurred in steel moment-resisting connections during the 1994 Northridge earthquake are examined from a fundamental point of view. This examination begins with a discussion of material properties, and calls attention to the shortcoming of the conventional tension test. The possible modes of failure are examined, showing the very limited view in the code design. Then, a simplified and more accurate analysis of the beam-column connection is examined. Recognizing that the unfused material between a column face and backing bar forms an 'artificial' edge crack, the methods of nonlinear finite element analysis combined with fracture mechanics were brought to bear. Using these procedures, it was possible to predict the instant of fracture, and to construct analytically complete hysteretic loops for the specimens. The report concludes by clearly showing that, at higher applied loads the bottom backing bar develops decidedly higher stresses at the column face than does the upper backing bar.
- Keywords
- Stress distribution; Stress intensity factors; Seismic design; Moments; Steel structures; Stress analysis; Structural members; Stress-strain relationships; Strain (Mechanics); Failure (Mechanics); Structural vibration; Cracking (Fracturing); Construction joints; Dynamic response; Finite element analysis; Earthquake engineering; Northridge earthquake; Mechanical properties; Dynamic structural analysis