Static Three Dimensional Analysis of Elevated Steel Transportation Structures.

摘要

A three-dimensional finite element modeling technique that may be used to statically analyze many classes of steel elevated transportation structures for design,analysis,and maintenance studies was developed and tested. Parameter studies on a typical class of steel elevated transit structure found in many cities showed that: (1) a 50foot long built-up plate girder representation modeled as 50beam elements and 100plate elements gave calculated shear and moment values that compared well with analytical values. The errors resulting from the use of fewer elements were found to be large. (2) Locations on the structure subjected to stress reversals or stress concentration are clearly indicated by the technique and show where damage due to fatique and deterioration is likely to occur. (3) Forces in cross-bracing and sway frames,which are not readily obtained in a conventional analysis,may be easily obtained. (4) Calculated deflection taking into account the three-dimensional effects of bracing and sway frames may be determined and compared with allowable values.