AMBER is an automated tool for performing transient loads analysis of structural systems composed of one or more flexible bodies. Each body is initially supplied in Craig-Bampton form. Two basic solution approaches are available: traditional system assembly and multibody. The traditional approach is better suited for linear systems or for comparison to legacy analysis; the multibody approach is better suited for systems having gap or friction nonlinearities at the body-to-body interfaces, or for non-traditional damping.

AMBER is a Fortran 90-based tool. The basic organizing concept is the body. One or more bodies can be input to the program and combined to simulate the system to be analyzed. A body consists of a degree of freedom (DOF) map, mass and stiffness matrices, and optionally, applied forces and output transformation matrices (OTMs). AMBER dynamically allocates the space needed to gather all data for a body into a single object using the Fortran 90 structure construct.

Bodies can then be combined into assemblies. Any supplied loads and/or OTMs are automatically absorbed into the resulting assembly and merged and/or transformed as needed. The resulting assembly can then be treated as a body in subsequent operations.

This is a new code that will allow the user to perform transient response analysis in a more efficient manner. Many of the supporting tasks are automatic, reducing sources of error. The single tool replaces multiple heritage tools used for the shuttle and Ares programs.

This work was done by Robert Franson and Xing Zhao of The Boeing Company for Johnson Space Center. For further information, contact the JSC Technology Transfer Office at (281) 483-3809. MSC-25246-1

NASA Tech Briefs Magazine

This article first appeared in the February, 2015 issue of NASA Tech Briefs Magazine.

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