Search results for "Polymer Matrix Composites"
showing 5 items of 5 documents
Infrared Thermography assisted evaluation of static and fatigue Mode II fracture toughness in FRP composites
2019
Abstract The work proposes the combined use of a Modified Transverse Crack Tension (MTCT) test coupon and Infrared Thermography, to evaluate the static and fatigue behaviour of Fibre Reinforced Polymer composites under Mode II delamination. Artificial delaminations starters are added to the TCT coupon, whose effects on the Strain Energy Release Rate are discussed. Infrared Thermography and Thermoelastic Stress Analysis are implemented to investigate stresses and delaminations growths on two FRP materials: a pre-preg IM7/8552 carbon fibre-epoxy and a glass-fibre reinforced epoxy laminates. The thermographic, thermoelastic and second harmonic signals have been obtained and used to monitor the…
Empirical model for stress ratio effect on fatigue delamination growth rate in composite laminates
2004
An empirical model is proposed for the stress ratio effect on the fatigue delamination growth rate in composite laminates under single-mode loading, intending to provide a simple and accurate description tool in engineering application. The model is based on heuristic considerations of damage accumulation ahead of the crack. Linear cumulative assumption is used for damage estimation. Comparison of the prediction based on the proposed model with the test results for different carbon, glass, and alumina fibre-reinforced composites at several stress ratios shows reasonable agreement.
Environmentally Friendly Composites and Surface Treatments for Metal-to-Composite Hybrid Joints for Marine Application
2022
In this study, the use of natural fibres (flax and basalt) in combination with a recyclable epoxy matrix based on cleavable amines is suggested for improving the sustainability of marine industry. In addition, a new and eco-friendly anodizing process based on tartaric sulfuric acid solution (TSA) and a pore widening step in a NaOH aqueous solution was carried out on aluminium alloy (AA5083) to evaluate its effect on the adhesion strength and damage tolerance after low velocity impact of co-cured adhesive joints with a basalt fibre reinforced and recyclable laminate. The durability in marine environment was simulated by exposing samples to salt-fog spray conditions over a period of 90 days. …
Reinforcement Efficiency of Cellulose Microfibers for the Tensile Stiffness and Strength of Rigid Low-Density Polyurethane Foams
2020
Rigid low-density closed-cell polyurethane (PU) foams are widely used in both thermal insulation and structural applications. The sustainability of PU foam production can be increased by using bio-based components and fillers that ensure both enhanced mechanical properties and higher renewable material content. Such bio-based foams were produced using polyols derived from rapeseed oil and microcrystalline cellulose (MCC) fibers as filler. The effect of MCC fiber loading of up to 10 wt % on the morphology, tensile stiffness, and strength of foams has been evaluated. For estimation of the mechanical reinforcement efficiency of foams, a model allowing for the partial alignment of filler fibers…
Predicting stiffness and strength of birch pulp:Polylactic acid composites
2016
This paper studies failure of birch pulp–polylactic acid composites. Stiffness and strength are calculated using the theory of short fibre composites and the results are compared to experimental data. The results differed from the experimental values by 0–6%. With less aligned fibres the short fibre theory is not feasible. The performance of the 40 wt% birch pulp – polylactic acid composite is predicted with X-ray microtomography based finite element modelling, and the results are compared with experiments. Stiffness results differed from experiments by 1–17% . By adding into the models a third material phase representing the interface between the fibres and the matrix, the stress–strain c…