A GEOMETRIC APPROACH TO STRAIN-DISPLA CEMENT MAPPING FOR SPACE TRUSS STRUCTURES

A strain-displacement mapping algorithm has been developed to estimate the deformation of space truss structures using the measurements of strains of individual struts. The algorithm relies solely on the geometry of the structure and does not require any knowledge of the material properties or dynamic characteristics of the structure. This algorithm is expected to be useful in estimating deformation of long booms which are employed to enhance the accuracy of the Global Positioning System based attitude determination systems. To examine the performance of the algorithm, experimental studies were conducted using a laboratory truss. The results indicate that the algorithm is capable of estimating accurately the displacements at various locations in the truss under static, dynamic and thermal loads. In order to reduce the number of strain gauges required, a sensor placement strategy was also investigated.