A three-dimensional scale model of a hexagonal boom truss of the then space station Freedom was built and tested in the laboratory. The purpose of the tests was to extract complete high-quality data of the vibrational characteristics of the structure, before and after damage, to validate damage detection/evaluation theories. The vibration tests consisted of experimental modal analysis before and after the infliction of artificial damage. The structure was subjected to IS different damage scenarios, at single and multiple locations, of three types: a) cut damage consisting of a cut through half the depth of the dement, b) partial damage removing 50% of the area over the middle third of the element, and c) complete damage caused by completely cutting through the member. All damages were induced without changing the mass properties of the structure through specially designed clamping devices. This paper summarizes the experimental program, the modal test results, the extracted modal shapes and an analysis implemented to localize the damage via modal strain energy distribution. The modal text results consist of the vibrational signatures due to different damages on the structure. The extracted modal results art implemented in a global damage detection/evaluation theory bared on modal swain energy distribution. The strain energy distributions due to the static shapes of the modes are computed before and after the inflicted damage. The differences from the normalized strain energy distributions are multiplied times element weight factors proportional to the Strain energy distribution of the damaged structure. The weighted modal Strain energy differences are lumped into the connecting nodes of the elements to provide indications of the locution of the inflicted damage. The technique is able to locate the complete damage and the partial damage, but was no, able to detect the cut damage.
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