Parametric study on factors influencing the stiffness of honeycomb sandwich panels using impulse excitation technique

Abstract

Metallic thermal protection systems are used to protect the airframe and pay load from aerodynamic and aerothermal heating in hypersonic cruise vehicles that are powered with advanced scramjet engines. Metallic thermal protection systems is a composite structure that contains honeycomb sandwich panels at the top and bottom and a variety of thermal insulating materials placed in between them. Several design factors influence the structural and thermal performance of the honeycomb sandwich panels. Panel bending stiffness is one important structural property that is generally estimated using a destructive 3-point or 4-point bending test. In this study, a numerical model based on the impulse excitation nondestructive evaluation technique has been developed to estimate the effect of various design parameters that affect the bending stiffness of the honeycomb sandwich panels. The results obtained are analyzed using standard statistical procedures. A major advantage of this method lies in evaluating the panel stiffness at the design stage without resorting to actual fabrication of the panels for destructive testing.

Analysis of effect of variation of Honeycomb core cell size and sandwich panel width on the stiffness of a sandwich structure

“…• It has been observed that honeycomb core cell size doesn't have a significant effect on the stiffness properties of a composite sandwich panel. This is in accordance with the observations made by Kiran et al [21] and Zhang and Ashbey [22] that the core cell size of a honeycomb core has negligible effect on the stiffness property of a composite sandwich panel. • Also it has been found that with increased panel width the stiffness of composite panel increases significantly.…”

“…Lister [18] also observed that Core ribbon orientation has an important role in a sandwich beam's bending behavior. Kiran et al [21] described that core cell size and core sheet thickness has negligible effect i.e. they contribute only 4% towards the stiffness per unit weight as compared to other design factors.…”

The efficient design of hybrid and metallic sandwich structures under air blast loading

“…The lightweight composite sandwich structure provided better impact resistance, maximum energy absorption, specific strength and stiffness as well as protection against blast [1][2][3][4][5]. Sandwich structures with a square honeycomb core are most commonly used for the protective layer against blast loading [2][3][4][5][6][7].…”

“…The lightweight composite sandwich structure provided better impact resistance, maximum energy absorption, specific strength and stiffness as well as protection against blast [1][2][3][4][5]. Sandwich structures with a square honeycomb core are most commonly used for the protective layer against blast loading [2][3][4][5][6][7]. The numerical results show that the sandwich failure behaviour undergoes large elastic deformation, shear band and bending failure at the end [2][3][4][5][6][7][8].…”

“…Sandwich structures with a square honeycomb core are most commonly used for the protective layer against blast loading [2][3][4][5][6][7]. The numerical results show that the sandwich failure behaviour undergoes large elastic deformation, shear band and bending failure at the end [2][3][4][5][6][7][8]. Al-Rifaie et al [6] numerically performed air-blast on layered trapezoidal, triangular, sinusoidal and rectangular corrugated sandwich panels by using 0.5 kg TNT at a 500 mm stand-off distance.…”