Compression properties of a novel foam-core sandwich cylinder reinforced with stiffeners

In some applications such as roofs and walls, it is important to supply low thermal conductivity and high bending stiffness to structures. Generally, foam materials are preferred, which have low thermal conductivity. However, bending stiffness and compression properties of foam materials are low. In this study, composite tubes were inserted to the foam core material to improve the compression and bending properties of the sandwich structure. Vacuum infusion method was used to manufacture the sandwich structure. The bending and compression performance of the structures with and without composite tubes were compared. To measure the bending stiffness and compression properties of the structure, three-point bending and compression tests were conducted according to American Society for Testing and Materials (ASTM) standards. The manufacturing procedure can be easily automated and applied to large and complex shape panels. In addition, a parametric analysis was done to investigate the effect of the number of tubes and the diameter of the tubes on bending and compression stiffness of the structure. According to the test results, the samples including the composite tubes gave six times higher bending stiffness as compared to the samples without the composite tubes. As the diameter of the tubes increased the bending stiffness and the ultimate core shear strength increased. In addition, the structures including 14 mm diameter tubes had higher specific absorbed energy values under compression loading.

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Experimental Study on Mechanical Properties of X-Cor Sandwich

Materials Science Forum ◽

10.4028/www.scientific.net/msf.686.411 ◽

2011 ◽

Vol 686 ◽

pp. 411-418 ◽

Cited By ~ 1

Author(s):

Jian Ping Bi ◽

Xu Dan Dang ◽

Xin Li Wang ◽

Jun Xiao ◽

Hai Jun Chen ◽

...

Keyword(s):

Mechanical Properties ◽

Experimental Study ◽

Foam Core ◽

Molding Process ◽

Shear Properties ◽

Insertion Angle ◽

Compression Properties ◽

Tension Properties ◽

Tension Strength

In this study, by changing Z-pin’s insertion parameters, the X-cor sandwich was prepared with vacuum curing molding process. The effects of Z-pin’s insertion angle, insertion density and diameter on compression, shear and tension properties were studied. The results show that Z-pin’s insertion parameters can significantly affect the mechanical properties of X-cor sandwich. The compression properties of X-cor sandwich are reduced, while shear properties are improved by the increase of Z-pin’s insertion angle. As Z-pin’s insertion angle increases the tension modulus increases while the tension strength firstly increases and secondly decreases. The mechanical properties increase with the increase of Z-pin’s insertion density and diameter. Compared with the foam core sandwich, the mechanical properties of X-cor sandwich are significantly improved in both modulus and strength.

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Effect of Core Architecture on Charpy Impact and Compression Properties of Tufted Sandwich Structural Composites

Polymers ◽

10.3390/polym13101665 ◽

2021 ◽

Vol 13 (10) ◽

pp. 1665

Author(s):

Chen Chen ◽

Peng Wang ◽

Xavier Legrand

Keyword(s):

Impact Resistance ◽

Charpy Impact ◽

Foam Core ◽

Structural Composites ◽

Absorbed Energy ◽

Compression Properties ◽

Obvious Benefit ◽

Negative Effect ◽

Charpy Absorbed Energy ◽

Liquid Resin Infusion

This study presents a novel sandwich structure that replaces the polypropylene (PP) foam core with a carbon fiber non-woven material in the tufting process and the liquid resin infusion (LRI) process. An experimental investigation was conducted into the flatwise compression properties and Charpy impact resistance of sandwich composites. The obtained results validate an enhancement to the mechanical properties due to the non-woven core and tufting yarns. Compared to samples with a pure foam core and samples without tufting threads, the compressive strength increased by 45% and 86%, respectively. The sample with a non-woven layer and tufting yarns had the highest Charpy absorbed energy (23.85 Kj/m2), which is approximately 66% higher than the samples without a non-woven layer and 90% higher than the samples without tufting yarns. Due to the buckling of the resin cylinders in the Z-direction that occurred in all of the different sandwich samples during the compression test, the classical buckling theory was adopted to analyze the differences between the results. The specific properties of the weight gains are discussed in this paper. The results show that the core layers have a negative effect on impact resistance. Nevertheless, the addition of tufting yarns presents an obvious benefit to all of the specific properties.

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