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In the current study, promising glass composites based on vanadium pentoxide (V2O5)- doped zinc borate (ZnB) were investigated in terms of their nuclear-radiation-shielding dynamics. The mass and linear attenuation coefficient, half-value layer, mean free path, tenth-value layer, effective atomic number, exposure-buildup factor, and energy-absorption-buildup factor were deeply simulated by using MCNPX code, Phy-X PSD code, and WinXcom to study the validation of ZBV1, ZBV2, ZBV3, and ZBV4 based on (100−x)(0.6ZnO-0.4B2O3)(x)(V2O5) (x = 1, 2, 3, 4 mol%) samples against ionizing radiation. The results showed that attenuation competencies of the studied glasses slightly changed while increasing the V2O5 content from 1 mol% to 4 mol%. The domination of ZnO concentration in the composition compared to B2O3 makes ZnO substitution with V2O5 more dominant, leading to a decrease in density. Since density has a significant role in the attenuation of gamma rays, a negative effect was observed. It can be concluded that the aforementioned substitution can negatively affect the shielding competencies of studied glasses. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

This paper focuses on a recently developed concept, in which glass is combined with timber to provide post-breakage strength and ductility. This combination allows for good post-breakage performance and overall robustness of timber-glass composite beams and wall elements, which has been reported in several publications. The application of timber-glass elements in practice, however, raises important issues related to structural fire performance. The paper elaborates on this issue and provides general information about the behavior of glass, timber and adhesives at elevated temperatures and under fire conditions. Furthermore, it presents ideas and strategies developed for potential application of timber-glass composites in practical situations. The paper presents also initial results from an on-going research project on fire performance of timber-glass composites Copyright © with the authors. All rights reserved.

Fibrous composite materials are being extensively used not only in the industrial application, but also in the daily life. The specific use of short fibres with thermosetting polymer has broadened its application owing to its economical constituents and simple manufacturing process. However, engineering designers and maintenance engineers have lacked confidence in using short-fibre composite on a long term basis. Hence, the development of fatigue model for short-fibre system is difficult due to the complexity of interaction between fibre ends and matrix. Furthermore, the sensitivity of thermosetting polymers to heat augments the difficulty in damage modelling of short-fibre reinforced composites. The exhaustive literature review on the fatigue modelling of composite materials is conducted, regarding a new finding that Poisson’s ratio plays a significant role in modelling damage in fatigue. The literature review identified the most suitable damage modelling approaches to predict remaining life of short-fibre composites under cyclic loading and elevated temperatures. Two types of modelling approaches are suggested in the present study, viz. phenomenological approach and the surrogate-assisted optimization modelling. First of all, a combined phenomenological mode is proposed using residual strength and stiffness degradation model combining with a temperature model as a function of strength variation. Second, a function approximation is developed in the present study using optimization technique assisted by a surrogate algorithm. Based on a considerable number of experimental data, the surrogate model was trained to define the non-linearity of the function to model the fatigue damage of short-fibre composites at elevated temperatures. Two sets of experiment were conducted with an objective of acquiring the material constants for the phenomenological model to train the data sets for the surrogate model as well as to verify the models proposed. The first set of exper

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In order for composites to become an accepted material for infrastructure application, life prediction and durability must be understood. The majority of studies have examined the strength and fatigue response of composites under hot and/or moist conditions. Various researchers have also studied life prediction methods for composite materials under fatigue, primarily for high performance applications. Little work has been done to study durability under combined service conditions for composites used in civil infrastructure applications. This thesis focuses on the development of a life prediction model for use with fiber reinforced polymer composites in bridge service environments. The Tom's Creek Bridge of Blacksburg, VA is used as a guiding case study. First, the tensile properties of the composite were studied as a function of temperature and moisture. Damage accumulation was studied as a function of cyclic loading and temperature cycles. The enviro-mechanical conditions, including moisture, temperature and fatigue loading, were then used in a computer simulation to predict the life of a vinyl ester/glass composite under an approximate bridge service environment. Finally, a laboratory simulation was conducted that approximates the temperature and humidity that is seen at the Tom's Creek Bridge, but in an accelerated time frame. A multi-stress fatigue pattern, mimicking cars and trucks passing over the bridge, was used. One year of conditions was accelerated to approximately six hours and thirty-three minutes using a servo-hydraulic test frame and environmental chamber. The final results showed that life prediction methodology conservatively predicted the lifetime of a vinyl ester/glass composite under the enviro-mechanical conditions. The damage of the composite was predominately driven by cyclic loading. The environmental conditions of moisture and temperature had only a small affect on the lifetime of the composite. This lack of environmental sensitivity is larg

A simulation model which incorporates the statistical- and numerical-based Lattice Green Function Local Load Sharing Model and a Fracture Mechanics-based Residual Strength Model has been developed. The model simulates creep rupture by imposing a fixed load of constant stress on the composite over the simulation duration. Simulation of the fatigue of glass fiber-reinforced composites is achieved by replacing the constant stress parameter in the model with a sinusoidal wave function. Results from the creep rupture model using fused silica fiber parameters, compare well with S-2 glass/epoxy systems. Results using Mandell's postulate that fatigue failure in glass fiber-reinforced polymeric composites is a fiber-dominated mechanism, with a characteristic slope of 10 %UTS/decade are consistent with available experimental data. The slopes of fatigue curves for simulated composites for three frequencies namely: 2, 5 and 10 Hz are within 12-14 %UTS/decade compared with that of 10.6-13.0%UTS/decade for unidirectionl glass reinforced composites (epoxy and vinyl ester) obtained from Demers' [40] data.