Structural Analysis

By applying the most advanced in progressive collapse analysis technology, ASI presents unmatched capabilities that overcome finite element analysis limitations for analyzing progressive collapse and providing performance-based design.

ASI’s Applied Element Method (AEM) based technology is the only analysis method for accurately analyzing the behavior of a structure during a critical failure and the resultant progressive collapse. By being able to analyze and predict the linear, nonlinear, and failure modes of structures, ASI’s engineers:

• Test structural elements and their effect on the overall integrity of the structure during a critical failure.
• Determine the change in internal forces resulting from the loss of structural elements.
• Analyze structural behavior in a 3D environment, highlighting global effects including catenary actions, collision and impact of flying debris, and collapse modes.
• Simulate the collapse in 3D showing the behavior of each element in the structure.
• Exceed General Services Administration (GSA) progressive collapse guidelines by analyzing the concurrent loss of multiple structural elements.

ASI’s analysis and simulations allow the teams responsible for designing structures to answer the following questions:

• Will the structure collapse in an extreme loading event?
• What is the severity of the collapse; is it local or global?
• Will first-response teams have time to evacuate the inhabitants?
• What is the collapse mode?
• Will surrounding structures be affected?
• What changes can be made to limit the spread of the failure and mitigate progressive collapse?

Improve structural integrity to accommodate local failures and mitigate progressive collapse.

ASI evaluates the structure’s integrity when it is subjected to the simultaneous failure of structural elements. Stress-redistribution is computed during periods of failure to provide real-time internal forces as they redistribute to neighboring elements. By knowing this information, ASI helps to:

• Develop plans for mitigating an extensive collapse
• Redesign and retrofit specific elements that can enhance the structure’s integrity

During progressive failure, each type of structural element becomes a contributing factor in the structure’s overall behavior. To satisfy this need, ASI developed AEM-based analysis as the most accurate method for tracking the behavior of the following elements during progressive failure:

Redundancy	Pre-cast elements	Masonry, reinforced and hardened walls
Alternate load paths	Rebar layout and stirrups	Trusses
Catenary effects	Composite and steel members	Nonlinear material models
Post-tensioned elements

Make architectural changes that will secure inhabitants during progressive failure and collapse.

Strategic positioning of architectural elements can make the difference during a collapse event between the total shutdown of a structure or its continuing viability.  More importantly, it can prevent the extensive loss of lives. By understanding the behavior of a structure during a progressive collapse event, ASI can help to determine the placement of critical architectural elements such as control rooms, power generators, HVAC systems, cafeterias, gathering areas, daycare centers, and other vital locations.

Progressive collapse analysis of a 15-floor tower

Stress redistribution and changing internal force diagrams during progressive collapse

Comparing between Applied Element Method and Finite Element Method for structural analysis