Impact damage characteristics of carbon fibre metal laminates : experiments and simulation

In this work, the impact response of carbon fibre metal laminates (FMLs) was experimentally and numerically studied with an improved design of the fibre composite lay-up for optimal mechanical properties and damage resistance. Two different stacking sequences (Carall 3–3/2–0.5 and Carall 5–3/2–0.5) were designed and characterised. Damage at relatively low energy impact energies (≤30 J) was investigated using Ultrasonic C-scanning and X–ray Computed Tomography (X-RCT). A 3D finite element model was developed to simulate the impact induced damage in both metal and composite layers using Abaqus/Explicit. Cohesive zone elements were introduced to capture delamination occurring between carbon fibre/epoxy plies and debonding at the interfaces between aluminium and the composite layers. Carall 5–3/2–0.5 was found to absorb more energy elastically, which indicates better resistance to damage. A good agreement is obtained between the numerically predicted results and experimental measurements in terms of force and absorbed energy during impact where the damage modes such as delamination was well simulated when compared to non-destructive techniques (NDT)

Surface Modification Effect of Volcanic Ash Particles Using Silane Coupling Agent on Mechanical Properties of Polyphenylene Sulfide Composites

The surface treatment of volcanic ash particles with various concentrations (1-3-5% (v/v)) silane coupling agent (3-aminopropyltriethoxysilane (3-APTS)) having organic functional group was conducted. After surface treatment, polyphenylene sulfide (PPS) composite samples containing surface treated volcanic ash particles at two concentrations (10 and 15 wt%) were manufactured by twin screw extruder and injection molding machine. This study investigated the effect of surface modification on mechanical properties of two different concentrated volcanic ash/PPS composites. All tests were performed using a Shimadzu AG-X Universal Tester. Tensile and three point bending tests were carried out at a crosshead speed of 1 mm/min and 2 mm/min according to ISO 527-2 and ASTM D790 standards, respectively. During the experiments, the relation between the mechanical properties and surface treatment concentrations of silane agent on volcanic ash/PPS composites was determined as a function of tensile strength and modulus, flexural strength and modulus. Moreover, fracture surface morphologies of volcanic ash/PPS composite samples were observed by using a scanning electron microscopy

Experimental study of temperature effect on the mechanical properties of GFRP and FML interface

Interface between laminates has always been the weakest part of bonded materials which is prone to delamination. This is even more prevalent in bonding of two different materials. The research aims to evaluate delamination of dissimilar materials under a range of temperature. This is a part of the experimental study to investigate the potential of fiber metal laminates (FML) to be used in high temperature environment. The mechanical response of interface of hybrid laminate was characterized at temperatures ranging from 30 to 110 °C. Double cantilevered beam (DCB) and end notched flexure (ENF) tests were conducted on glass fiber laminated aluminum specimens to obtain Mode-I and Mode-II delamination properties with use of data reduction. Mode-I fracture toughness (GIC) is significantly degraded by 59.45% at 70 °C and up to 83.65% at 110 °C. Mode-II fracture toughness (GIIC) only slightly degrades by 10.91% at 70 °C but drops rapidly by 82.84% at 110 °C