Identification of Axial Forces in Structural Rod Members Under Compression by a Modal Approach

The identification of axial forces in structural members by means of identified modal parameters has been the subject of numerous studies in the last decade. In most cases, the estimation of tensile forces is considered. However, only a very few publications also address the identification of compressive axial forces. One problem in modal testing of compression members is the control of the boundary conditions that have also an important influence on the dynamic behavior of the system. In this contribution, an experimental study is presented that shows how the modal behavior of a steel rod in a compression test changes with an increasing axial compression loading.