The effect of carbon nanotubes modified polyurethane adhesive on the impact behavior of sandwich structures

Abstract

Sandwich panels with aluminum honeycomb cores have emerged as an essential class of lightweight building materials in a wide variety of structural engineering areas, including marine, railway, aerospace, and automotive structures. Although sandwich structures offer remarkable mechanical properties, for instance, high specific strength and stiffness, these structures are open to the damage created by the low-velocity impact. This study investigates the dynamic behavior of aluminum honeycomb sandwich panels with different core cell sizes based on neat and multi-walled carbon nanotube (MWCNT) reinforced polyurethane (PU) adhesives that are aimed. The enhancement in impact performance of honeycomb sandwich structures obtained by the inclusion of MWCNTs in the PU adhesive is investigated. The effect of the MWCNT reinforcements on square sandwich panels at 50 J energy level is examined using an instrumented drop tower test setup. After acquiring load-time histories, the numerical integration method is implemented to obtain loaddeflection and energy-time curves. Also, energy balance modeling (EBM) is

Experimental investigation on low-velocity impact response of spherical core sandwich structure

“…Similar types of failure patterns with multiple peaks are observed for the 5 and 7 m/s velocities also. The honeycomb sandwich structures 33,47 as well as truss core, 48 also exhibit a similar type of multiple failure patterns.…”

Preparation and characterization of an eco‐friendly sand‐fixing agent utilizing nanosilica/polymer composites

“…For example, nanosilica, nanocarbon tubes, and various nanosized fillers or intensifiers are added to the materials to form composite materials 36,37 . The improvements caused by nanomaterials can be attributed to two aspects: (1) Nanosized particles of nanomaterials can cause changes in physical aspects, resulting in filling effects, and further improvement in mechanical properties 38–40 ; (2) Nanomaterials have higher surface energies, which strengthens the cementation between adjacent materials 41–44 . Among various nanomaterials, nano‐SiO 2 (NS) is a useful nanomaterial, and it has low production costs and a good cementation effect.…”

“…36,37 The improvements caused by nanomaterials can be attributed to two aspects: (1) Nanosized particles of nanomaterials can cause changes in physical aspects, resulting in filling effects, and further improvement in mechanical properties [38][39][40] ; (2) Nanomaterials have higher surface energies, which strengthens the cementation between adjacent materials. [41][42][43][44] Among various nanomaterials, nano-SiO 2 (NS) is a useful nanomaterial, and it has low production costs and a good cementation effect. With the development of nanotechnology, the nanomaterials have been applied as new additives for sand improvement.…”

Assessment of damage tolerance of bolted composite structures via “bearing‐after‐impact” tests

“…[10,11] Previous studies have indicated that the primary concern for the composite structures is the losing their reliability after the impact damage. [12][13][14] Furthermore, fabric design and resin toughness, ambient conditions, impactor geometry, and multiple impact loadings have a role on FRP impact resistance and damage tolerance. [12,15] Moreover, the effects of these factors on the damage tolerance of FRPs were intensively investigated by tensile, compression, and flexural tests after the impact test.…”