Compression Capacity of Corrugated Core Hybrid Composite Sandwich Structure

Abstract

Improvement of mechanical properties of light-weight corrugated core sandwich structures is a big demand in aerospace applications. Among these applications, space vehicles which encounter pressure loads and severe aerodynamic heating during ascent and reentry. The open-cell corrugated core is useful for active cooling of the sandwich structures. In this work, hybrid composite structural members with fiberglass corrugated core and carbon fiber skin facings were manufactured using vacuum bag technique. Different specimen configurations with rectangular cross-section area have been subjected to the load in the longitudinal direction of the corrugation and examined by edgewise compression test. The proposed testing has been applied to take advantage of the highest inertia of the specimen in such orientation. The test provides a basis for estimating the load carrying capacity when these structure members are used as individual webs in the aircraft interiors. Also as the core sheet is turned by 90° to the regular load direction, this structure member is similar to the so-called honeycomb when ordered in parallel rows and hence it is appropriate for floor sandwiching. In contrary to a honeycomb, this core consists of fiberglass laminate and therefore higher compressive resistance is associated. The results exhibit high values of both stiffness and ultimate compression force in the corrugation direction. For the rectangular area and the open corrugated contour, specific properties relative to the weight are extremely high. Also, the results and graphs indicate that there must be at least three corrugated ligaments with a trapezoidal cross section of 0.5” height and 63o per cell to grantee stability under load and high absorbed energy in the non-linear stage as well.

Fracture Resistance of Composite Structurs From Hemp Bio-Fibers

“…Some failures modes have been observed by [14] in metallic skin sandwiches (general buckling, wrinkling, core crushing, and core/skin debonding) are similar to the composite skin sandwich in the current work [14]. Also, failure mode in the form of tearing at the carbon sheet edges is similar to the same composite sheets when holding fiberglass corrugated laminate core inside [1].…”

“…The cores are balsa wood, foam, and paper board (carton) honeycomb. The curing process was carried out using a vacuum bag technique for 2 hours at 130 o C. The details of the curing system of the carbon composite were discussed before by Nagwa Elzayady & Eltahry Elghandour [1]. The cooked specimens (Figure 3) were cut using a diamond saw into groups according to the skin and core types (Figure 4).…”

“…Improvement of mechanical properties of structures is a big demand in aerospace applications as they are highly efficient when it comes to light-weight and stiff components [1][2][3][4][5]. The sandwich structure plays an essential role in such modern manufacturing industries [6][7][8].…”

Design optimization to improve the performance of the aircraft composite structures

“…The failure mode in Ref. [19] exhibited fracture at the mid-plane of the core which was perpendicular to the load direction, whilst the carbon skin plies underwent less delamination and their edges experienced less tearing (i.e., less energy absorbed) as shown in Fig. 10(a).…”