Patents Assigned to Structural Design Engineers
  • Publication number: 20040003548
    Abstract: An improved framed structure incorporating a coupled-girder system provides enhanced seismic energy dissipation by as much as 30% over that provided by conventional yielding of the girders. The coupled-girder system includes a pair of spaced-apart girders coupled by one or more girder-to-girder links which are preferably vertical links. Energy dissipation takes place when the structure drifts beyond its elastic limit and the differential displacement of the pair of girders causes the web of each vertical link to shear yield. The links are proportioned to remain in the elastic regime under wind loads and moderate earthquakes as prescribed by building codes. Beyond the elastic limit, preferably the yielding in the links will take place prior to that in the girders. In this way, the links will be the first line of defense for dissipating seismic energy before the girders themselves.
    Type: Application
    Filed: February 28, 2003
    Publication date: January 8, 2004
    Applicant: Structural Design Engineers
    Inventor: Rajendra Sahai
  • Patent number: 6412237
    Abstract: An improved framed structure incorporating a coupled-girder system provides enhanced seismic energy dissipation by as much as 30% over that provided by conventional yielding of the girders. The coupled-girder system includes a pair of spaced-apart girders coupled by one or more girder-to-girder links which are preferably vertical links. Energy dissipation takes place when the structure drifts beyond its elastic limit and the differential displacement of the pair of girders causes the web of each vertical link to shear yield. The links are proportioned to remain in the elastic regime under wind loads and moderate earthquakes as prescribed by building codes. Beyond the elastic limit, preferably the yielding in the links will take place prior to that in the girders. In this way, the links will be the first line of defense for dissipating seismic energy before the girders themselves.
    Type: Grant
    Filed: December 3, 1999
    Date of Patent: July 2, 2002
    Assignee: Structural Design Engineers
    Inventor: Rajendra Sahai