NON-LINEAR STABILITY CRITICAL LOADS OF SINGLE-LAYER AND DOUBLE-LAYER RETICULATED SPHERICAL SHALLOW SHELLS BASED ON CONTINUUM ANALOGY METHOD

Continuum analogy method is an important approach for the stability analysis of reticulated shells, but there still exist imperfections in applying this method to reticulated spherical shallow shells. Based on the classical shell theory, single-layer and double-layer reticulated spherical shallow shells are treated as equivalent thin solid shells. Governing equations for the equivalent shells are established based on the non-linear stability theory and then solved by the Ritz method to provide theoretical upper and lower critical loads. Through a major parametric study (more than 1000 numerical examples), theoretical solutions for the critical load coefficients of reticulated spherical shallow shells with normal triangle grids are obtained. Compared with existing solutions, the proposed formulae are more perfect and accurate. Though the finite element technology becomes quite popular today, the continuum analogy method still provides an important guidance to the determination of critical loads of reticulated shells, and is also a supplement to the finite element method in the stability design of reticulated shells.