Browsing NTNU Open by Author "Krauklis, Andrey"
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Dissolution kinetics of R-glass fibres: Influence of water acidity, temperature, and stress corrosion
Krauklis, Andrey; Gagani, Abedin; Vegere, Kristine; Kalnina, Ilze; Klavins, Maris; Echtermeyer, Andreas (Journal article; Peer reviewed, 2019)Glass fibres slowly degrade due to dissolution when exposed to water. Such environmental aging results in the deterioration of the mechanical properties. In structural offshore and marine applications, as well as in the ... -
Dissolving Cylinder Zero-Order Kinetic Model for Predicting Hygrothermal Aging of Glass Fiber Bundles and Fiber-Reinforced Composites
Krauklis, Andrey; Echtermeyer, Andreas (Chapter, 2018)Glass fibers and fiber-reinforced composites degrade when exposed to water. Understanding the dissolution behaviour of glass in fiber-reinforced composites is necessary to predict the changes in physical and mechanical ... -
Hygrothermal Aging of Amine Epoxy: Reversible Static and Fatigue Properties
Krauklis, Andrey; Gagani, Abedin; Echtermeyer, Andreas (Journal article; Peer reviewed, 2018)Fiber-reinforced polymers (FRP) are widely used in structural applications. Long-term properties of such materials exposed to water are of high concern and interest, especially for subsea and offshore applications. The ... -
Long-Term Dissolution of Glass Fibers in Water Described by Dissolving Cylinder Zero-Order Kinetic Model: Mass Loss and Radius Reduction.
Krauklis, Andrey; Echtermeyer, Andreas (Journal article; Peer reviewed, 2018)Glass fibers are degraded when they are exposed to water. In this work, a model is developed that uses zero-order kinetics for predicting a decreasing glass fiber radius. The model is used to describe experimental test ... -
Long-Term Hydrolytic Degradation of the Sizing-Rich Composite Interphase
Krauklis, Andrey; Gagani, Abedin; Echtermeyer, Andreas (Journal article; Peer reviewed, 2019)Glass fiber-reinforced composites are exposed to hydrolytic degradation in subsea and offshore applications. Fiber-matrix interphase degradation was observed after the matrix was fully saturated with water and typical water ... -
Long-term ISO 23936-2 sweet oil ageing of HNBR
Akulichev, Anton; Alcock, Benjamin; Krauklis, Andrey; Tiwari, Avinash; Echtermeyer, Andreas (Journal article; Peer reviewed, 2021)A hydrogenated nitrile butadiene rubber (HNBR) compound is subjected to ageing in a simulated oil and gas environment in accordance with ISO 23936-2 standard at two elevated temperatures (130 °C and 150 °C) for a period ... -
Modified Ginstling-Brounstein Model for Wet Precipitation Synthesis of Hydroxyapatite: Analytical and Experimental Study.
Krauklis, Andrey; Kreicbergs, Imants; Dreyer, Ilo (Journal article; Peer reviewed, 2018)Purpose: Hydroxyapatite is the main mineral component in bones and teeth, thus being an important material in bone tissue engineering, e.g., for replacement and elimination of defects. Hydroxyapatite is widely used in ... -
Orthotropic fluid diffusion in composite marine structures. Experimental procedure, analytical and numerical modelling of plates, rods and pipes
Gagani, Abedin; Krauklis, Andrey; Echtermeyer, Andreas (Journal article; Peer reviewed, 2018)Finite elements simulations of fluid diffusion for composite structures are becoming more common in marine and offshore applications. Input parameters for such simulations are the orthotropic diffusion constants for the ... -
Prediction of Orthotropic Hygroscopic Swelling of Fiber-Reinforced Composites from Isotropic Swelling of Matrix Polymer
Krauklis, Andrey; Gagani, Abedin; Echtermeyer, Andreas (Journal article; Peer reviewed, 2019)Swelling in fiber-reinforced composites is anisotropic. In this work, dealing with glass fiber epoxy composite immersed in distilled water, swelling coefficients are obtained in each direction experimentally. Swelling ... -
Time-Temperature-Plasticization Superposition Principle: Predicting Creep of a Plasticized Epoxy
Krauklis, Andrey; Akulichev, Anton; Gagani, Abedin; Echtermeyer, Andreas (Journal article; Peer reviewed, 2019)Long-term creep properties and the effect of water are important for fiber reinforced polymer (FRP) composite materials used in offshore applications. Epoxies are often used as a matrix material in such composites. A typical ... -
Use of Synthetic and Natural Zeolites Tailored for As(V) Sorption
Krauklis, Andrey (Chapter, 2018)Arsenic in drinking water poses serious potential health risks in more than 30 countries with total affected population of around 100 million people. Natural and synthetic zeolites can be tailored in order to obtain improved ... -
Zero Stress Aging of Glass and Carbon Fibers in Water and Oil—Strength Reduction Explained by Dissolution Kinetics
Echtermeyer, Andreas; Krauklis, Andrey; Gagani, Abedin; Sæter, Erik (Journal article; Peer reviewed, 2019)Understanding the strength degradation of glass and carbon fibers due to exposure to liquids over time is important for structural applications. A model has been developed for glass fibers that links the strength reduction ...