Experimental and numerical analysis of sandwich panels with hybrid core

Abstract

The paper presents the experimental and numerical studies of sandwich panels with a hybrid core. The sandwich panel consists of external steel facings and a core, which is made of polyurethane foam or mineral wool or a combination of those two materials. The polyurethane foam material has a low weight and high thermal insulation properties, while the mineral wool material can provide high acoustic insulation and excellent fire resistance. Various proportions of the core materials are taken into account. It is assumed that a proper combination can provide the benefits of both materials. The structural behavior of a sandwich structure with a hybrid core is observed during laboratory tests. The failure mechanism is investigated in a four-point bending test. The material parameters of the core and facings are determined in standardized tests. The obtained parameters are used for FE simulations of the four-point bending tests. The criteria of damage initiation and propagation are defined in the interface layer of the numerical model. A satisfactory correlation between laboratory tests and numerical results is reported. Additionally, the sensitivity analysis of the numerical model response to the variation of the parameters of the interface is presented.

Flexural behavior of composite structural insulated panels with magnesium oxide board facings

“…Classical sandwich theory [7,8] and other equivalent single-layer models [21,22] were used when detailed core deformation analysis was not necessary [5,9,23,24]. A fully threedimensional approach was utilized to obtain more precise core strain state information, by discretizing all layers with solid elements [14,24,25], or using a combination of the shell (facings) and solid elements (core) to reduce the computational cost [16,[26][27][28][29][30][31]. Two-dimensional models were formulated within assumptions of plane stress conditions, allowing for enhanced meshing and more detailed results [32].…”

“…Two-dimensional models were formulated within assumptions of plane stress conditions, allowing for enhanced meshing and more detailed results [32]. In delamination failure analysis, contact at the interface had to be included [27]; however, when this behavior was not observed before failure initiation, perfect bonding between layers was assumed instead [25][26][27][28][29][30][31][32]. Nonlinear behavior was included in the material models of facings [29], core [16,25], or both [26][27][28]30] depending on failure progression.…”

“…In delamination failure analysis, contact at the interface had to be included [27]; however, when this behavior was not observed before failure initiation, perfect bonding between layers was assumed instead [25][26][27][28][29][30][31][32]. Nonlinear behavior was included in the material models of facings [29], core [16,25], or both [26][27][28]30] depending on failure progression. It was shown, that the consideration of the postyield core behavior has a significant role in the modeling of soft foam panels [16,25] and that the complex phenomena occurring at the supports before failure depend strongly on the combination of normal and shear stress distribution [28].…”

“…It was shown, that the consideration of the postyield core behavior has a significant role in the modeling of soft foam panels [16,25] and that the complex phenomena occurring at the supports before failure depend strongly on the combination of normal and shear stress distribution [28]. The geometrical nonlinearity was included, when significant deformation affected the load distribution [14,[25][26][27][28][29].…”

Numerical modelling of sandwich panels with a non-continuous soft core

“…One of the few papers devoted to the structural behavior of sandwich panels with mineral wool concentrates on wrinkling phenomenon [12]. In the paper [13], the results of laboratory tests and numerical simulations of panels with a hybrid core were presented. The influence of different proportions of mineral wool and polyurethane foam on the results of the fourpoint bending tests were investigated.…”