An improved third order theory and assessment of efficient zigzag theory for angle-ply flat hybrid panels

A new improved third order theory (ITOT) is presented for hybrid piezoelectric angle-ply flat panels under thermal loading. The transverse deflection is approximated nonuniformly to explicitly account for the transverse strain due to temperature and electric potential which are approximated as piecewise linear. The governing equations are derived using Hamilton's principle. The ITOT and an existing efficient zigzag theory are assessed for simply- supported angle-ply flat hybrid panels for static loads and for natural frequencies by comparison with 2D solutions. The comparisons for test, composite and sandwich panels establish that for most cases the zigzag theory is very accurate and ITOT is an improvement over the third order theory (TOT) based on uniform approximation of deflection across the thickness. (c) 2007 Elsevier Ltd. All rights reserved.