Characteristic stiffness method for static stability analysis and assessment of spatial structure

A scalar quantity denoted characteristic stiffness was suggested and its calculation formula was derived in order to directly reflect the evolution of overall structural behavior in static stability analysis and solve the problem of how to properly select these representative node. The state of structure can be defined as unstable when the value of structural characteristic stiffness is equal to zero in stability analysis. The characteristic curve was proposed to describe the overall mechanical behavior of the structure among the stability analysis combined with the accumulated work increment and the characteristic displacement. The static non-linear analysis was conducted on a K6 single-layer reticulated shell and a conference center roof shell. The critical loads obtained from the characteristic curves are equal to those from single nodal load-displacement curves. The characteristic curves are more stable and easier for understanding compared with the single nodal load-displacement curves. because the characteristic curves do not rely on representative node selection and can reflect the overall structural stiffness.