Interaction of member and node instability in the single layer reticulated shell

Damir LAZAREVIĆ

Professor

Faculty of Civil Engineering Univ. of Zagreb, Croatia damir@grad.hr

Damir Lazarević, born 1967, received his doctoral degree from the Univ. of Zagreb, Croatia in 2000.

Petra GIDAK

Research assistant

Faculty of Civil Engineering Univ. of Zagreb, Croatia pgidak@grad.hr

Petra Gidak, born 1980, received his civil engineering degree from the Univ. of Zagreb, Croatia in 2003.

This paper deals with stability of single-layer lattice dome. The local instability phenomena caused by member or node instability are fairy known. This paper analyses the interaction of these two forms with presence of geometrical imperfections, including influence on stability behaviour.

Spatial model used to describe these phenomena consists of six pin-jointed elastic members shaped as a regular pyramid and supported by horizontal elastic springs. Using this model, member and node equilibrium curves with influence of geometrical imperfections are separately produced. In addition, the interaction of buckling modes is detected and the corresponding postbuckling curves are produced. Finally, the imperfection sensitivity surface is elaborated and some general conclusions are made.