Novel higher-order zigzag theory for analysis of laminated sandwich beams

Abstract

In the present work, a new higher-order zigzag theory is proposed for the analysis of laminated sandwich beams under static and free vibration conditions. Fourth-order in-plane and transverse displacement fields are chosen along with linear unit Heaviside step function. The present theory satisfies interlaminar transverse stress continuity conditions along with zero value at the top and bottom surface for transverse shear stresses. The proposed approach is also free from any kind of C-1 or penalty requirements. A three-noded one-dimensional finite element having eight degrees of freedom per node is used during analysis. The efficiency of the proposed model is carried out by comparing the present results with those available based on elasticity solutions and zigzag theories in the literature. New results are also reported in the present work, which will serve as a benchmark for future studies. The influence of boundary condition on the nature of stress distribution across the length of beam and frequencies of the beam with different end conditions is also carried out. A comparative study has also been carried out between symmetric and unsymmetric laminated sandwich beam.

Effect of Thickness Stretching on the Natural Frequencies of Layered Composite Beams

“…For the present study a 2-D Stress-Strain relationship is used to determine the stresses. The constitutive relations for the k th layer are stated as ( ) ( ) ( ) 11 13 13 33 55 0 0 0 0…”

“…6.128 6.945 ------------Aydogdu [14] 6.144 ----7.218 --------Vo and Thai [15] 6.058 6.909 7.204 7.296 ----Vo et al [16] 6.090 6.918 7.207 --------Matsunaga [17] 6.144 6.991 [13] 9.208 13.614 ------------Vo and Thai [15] 9.206 13.607 16.327 17.449 ----Chalak et al [20] 9.208 13.611 16.336 --------Aydogdu [14] 9.207 ----16.337 --------Vo et al [16] 9.294 13.616 16.326 --------Matsunaga [17] 9.817 14.149 ------------Timoshenko [3] 9.205 13.670 ------------Bernoulli-Euler [1,2] 17.42 17.632 ------------…”

Free vibration analysis of bio-inspired helicoid laminated composite plates

“…Liew et al 32 summarized the available LWTs for the analysis of laminated composite plates. The problems of stress concentration, 33,34 stress channeling, 35,36 and delamination 37 are commonly observed in the case of laminates. To cater to the problems posed by laminates, 38 functionally graded materials (FGM) were discovered, in which the material properties vary in the particular direction in a desired way.…”

Research on Modal Test for a Double-layered Stiffened Plate in Water

“…Garg et.al. [4] put forward a new high-order theory to analyze the mechanic and free vibration of sandwich beam. Peng et.al.…”