System and method for analyzing structures subjected to catastrophic events

A computer-implemented method for analyzing a structure comprising:

• receiving linear elastic input data of a structure;
• automatically determining non-linear input data based on the received linear elastic input data;
• analyzing the determined non-linear input data through a non-linear analysis technique;
• and
• outputting the result of analysis including at least global damage measure including one or more of a global displacement ductility and number of damaged members, regional damage measure including one or more of inter-story drifts, inter-story shears, number of damaged members in a region, and identification of damaged members;
• and local damage measure including one or more of maximum member ductilities, cumulative member ductilities and number of cycle reversals,
• wherein the step of analyzing includes at least two or more of:
• using a minimization technique to minimize the storage requirements of a global stiffness matrix and local stiffness matrix;
• using a numerical solution technique that requires only one copy of the global stiffness matrix;
• reformulating and reducing only a portion of a global stiffness matrix that changes due to change in member state;
• using a sufficiently higher order integration method to increase the step size thereby reducing the number of steps required for analysis.