Effect of Strain-Rate on Flexural Behavior of Composite Sandwich Panel

Abstract

In the past few decades, Composite Sandwich Panel (CSP) technology significantly influenced the design and manufacturing of high performance structures. Although using CSP increases the reliability of structure, the important concern is to understand the complex deformation and damage evolution process. This study is focused on the mechanical behaviour of CSP under flexural loading condition. A setup of three-point bending test is prepared using three support span of 40, 60 and 80 mm. The loading was controlled by three different displacement rates of 1, 10 and 100 mm per minute to examine the effects of strain-rate on bending behaviour of CSP material. The beam span significantly affects the flexural stiffness of CSP panel. The load-deflection response of the panel shows two different portions, that representing equivalent elastic and plastic regions in both the core and facesheets components of CSP. The non-combustible mineral-filled core appears to be nonlinear in the elastic region, at high loading rate. Consequently the failure occurs as the core/facesheets interface suffers debonding.

Polyester Pinning Effect on Flexural and Vibrational Characteristics of Foam Filled Honeycomb Sandwich Panels

“…Figure 8 shows the stress-deflection curve of PFHS panels under flexural test. The similar behavior was obtained from a study on sandwich panel of mineral filled core (Abdi et al 2012). At low strain rates, failure initiated on the core prior to face sheet and at high strain rates failure takes place on face sheet prior to core.…”

An Energy-Based Concept for Yielding of Multidirectional FRP Composite Structures Using a Mesoscale Lamina Damage Model

“…The general loading on composite structures, including axial, flexural, and torsional loads, generates a complex stress state in the material. Consequently, a mechanics-equivalent stress quantity is determined in comparison with the corresponding property at the yield of the material [14][15][16][17][18][19][20]. The Tsai-Wu theory (1970), as one of the first failure criteria, was established based on Hill's theory of the macroscopic yielding of anisotropic metals, to predict the yielding of composite materials [21,22].…”

Failure of Glass Fibre-Reinforced Polypropylene Metal Laminate Subjected to Close-Range Explosion

“…Furthermore, by comparing different thermoplastic resin such as polypropylene, high density polyethylene, low density polyethylene, nylon 6.6, and nylon 6, the lowest density polypropylene can reach 700% elongation at breakage [ 18 ] which is useful in dissipating the blast energy. Some researchers investigated fibre metal laminates [ 20 , 21 , 22 , 23 ] or sandwich structure with FML face sheet [ 24 ] over impulsive loading through experimental or FEM method [ 25 , 26 ]. Langdon et al have defined the blast pressure distribution as a function of time and radial position of FMLs experimentally [ 27 ].…”

“…The strain rate dependency of the glass fibre polypropylene laminate was experimentally proved by Brown et al [ 30 ]. Furthermore, this characterization was used to define strength rate dependent of candidate material GFPP in FMLs modelling during blast loading [ 25 , 26 , 27 , 28 , 29 ]. Different damage models have been used to calculate the effect of GFPP damage in FMLs modelling when exposed to localized loading.…”

“…Different damage models have been used to calculate the effect of GFPP damage in FMLs modelling when exposed to localized loading. Several studies have been conducted to use instant damage failure model and damage variables to control the degradation of the stiffness matrix, hence defining the damage evolution in composite material response [ 25 , 26 , 29 ]. In FML structures the stress wave propagation through thickness has a significant effect in the final damage mode and panel response.…”