Analysis of reinforced or cellular panels and decks

Abstract

A popular and efficient design for lightweight structural decks, floors, roofs and wall panels consists of a flat plate reinforced by and composite with one or two sets of ribs. A variation of the reinforced plate is the so-called cellular construction comprised of two membranes connected to ribs to from a discrete core sandwich structure. Until recently, no rational methods were available for the stress and deflection analysis of these structures. This paper presents formulas for the exact elastic analysis of P late- S tringer- D iaphragm decks (composite stringers and non-composite diaphrams) and waffle decks (stringers and diaphrams both composite) which are rectangular with simple end and flexible side supports. Cellular construction is dealt with by creating a condition of anti-symmetry with respect to the middle plane. The formulas are derived by finding closed form solutions to the summation equation mathematical models which were written by use of a macro discrete field approach. The formulas are numerically illustrated through use of a simple programmable pocket calculator which is judged suitable for design office use and optimization studies. The examples permit comparisons between the single plate and cellular P-S-D panels and waffle plates.