Papers by Keyword: Toughness

Abstract: In this study, the strength properties and durability of polymeric fibre-reinforced concrete containing renewable oil palm shell (ROPS) lightweight aggregate were investigated. The effect of individual Polyvinyl Alcohol (PVA) fibre, individual Polypropylene (PP) fibre and hybrid PVA-PP fibre with various percentage of volume fraction, V_f (0, 0.3 and ‘0.25+0.05’%) on the compressive strength and toughness indices of ROPS LWC were examined. The research outcomes show that compressive strength of ROPS lightweight concrete strengthened with individual PVA fibre or PP fibre enhanced with the increase of V_f fibre. From the results, toughness indices increased significantly by 38.3% compared to control mix. Furthermore, the hybrid ‘PVA0.25/PP0.05’ had revealed the optimum results as associated to other mixes. Thus, the outcomes of this paper showed that the blend of both PVA and PP polymeric fibre could potentially be utilized in concrete industry.

Abstract: This work is based on an investigation study to develop bio-composite materials that are renewable, biodegradable, and environmentally safe. The fibers used in this work are extracted from the plant Ampelodesma Mauritanica, It is a wild plant that is produced in abundance in the Mediterranean regions. Through this work, an overview of Diss fibers was provided, developing bio-composite using different starch matrices reinforced by Diss fibers, and evaluate their mechanical behavior using Charpy-tests to determine standard test specimens to estimate Weibull parameters suitable for the composite using statistical methods based on Weibull distribution. The obtained results, it was found that the bio-composite starch/Diss 40% Glycerol and 5% fiber reinforcement (SG40/RF5) had better results compared to the rest of the bio-composite, The Charpy impact energy modulus was about 31.25 (KJ/m²), which is 2.1 times higher than that achieved Measured from SG40 matrix (40% glycerol), and 1.3 times higher than those fortified with 10% fiber SG40/RF10 (40% glycerol reinforcement 10% fiber), and the statistical study confirmed the distribution of the results obtained, especially Weibull, which has three parameters.

Abstract: In this study, stereolithography (SLA) 3D printing was used to prepare toughened composites by facile blending of chemically compatible nanoscale polyhedral oligomeric silsesquioxanes (POSS) to commercial photoreactive resin. Due to the complex nature of 3D printing, the mechanical performance of the final parts cannot be simply determined or even estimated until they are manufactured and tested. Thus, response surface methodology (RSM) and artificial neural network (ANN) were used to build regression models for determining the toughness of fabricated composites as function of toughener (POSS) amount and printing conditions (layer thickness and annealing temperature). The influence of the mentioned process parameters on toughness were investigated through a 17-run three-factor three-level Box-Behnken RSM design (BBD). The same experimental design was also used to acquire a data set for ANN. Finally, both the modeling methodologies were compared by coefficient of determination (R²) and residual distribution values. Results reveal that ANN possesses a better data fitting and predictive power as compared to RSM.

Abstract: The flexural behavior of Incinerated Bio-Medical Waste Ash (IBWA) – Ground Granulated Blast Furnace Slag (GGBS) based Reinforced Geopolymer Concrete (RGPC) beams with Waste Glass Powder (WGP) as fine aggregate is explored in this research. The fine aggregate (M-Sand) is substituted by varying the waste glass powder as 0 percent, 5 percent, 10 percent, 15 percent, 20 percent, 25 percent, 30 percent, 35 percent, 40 percent, 45 percent, and 50 percent, and the mixture is cured under atmospheric curing. The impact of the WGP weight percentage on the flexural behavior of GPC beams is analyzed. The conduct of RGPC beams varies from that of ordinary Portland Concrete (OPC) beams, which is defined and examined. Deflection, ductility factor, flexural strength, and toughness index were measured as flexural properties for beams. In contrast to the reference beams, the RGPC beams containing 50% Waste Glass Powder as fine aggregate demonstrated a major increase in cracking resistance, serviceability, and ductility, according to the experimental finding. The RGPC beam without WGP ended in failure with a brittle manner whereas those beams with WGP encountered ductile failure. The RGPC beams' load ability improved by up to 50% as the weight percentage of WGP was enhanced.

Abstract: This present study has been re-established to investigate failure mode and resistance characteristics of the PC/ABS blends and their ABS constituents under impact for a range of rubber contents. This present study has still been experimentally performed under an instrumented-drop weight impact test (DWIT) at a room temperature. It has been finally revealed that with a particular size of rubber particle, content of rubber significantly influenced impact failure modes and impact resistances of the PC/ABS blends and their ABS constituents as well. The test results showed that impact strength of the blends was improved about 23.22% and 155.33% due to increase in content of rubber up to 15 wt% and 20 wt%, respectively. There was also found that an increase in impact toughness of the blends for 57.48% and 239.23% was due to increase in content of rubber up to 15 wt% and 20 wt%, respectively. Whilst, impact strength of the ABS was improved about 392.98% and 190.12% due to increase in content of rubber up to 15 wt% and 20 wt%, respectively. An increase in impact toughness of the ABS for 308.20% and 172.56% was due to increase in content of rubber up to 15 wt% and 20 wt%, respectively.

Abstract: The effect of solution temperature and aging temperature on mechanical properties and microstructure of the new ultrahigh strength stainless steel S280 was investigated by heat treatment process experiment. The results showed that the optimal heat treatment process was as follows: heating to 1080 °C，holding for a hour, and quenching in oil; cooling to -73 °C, holding for 2 hour, and warming in air to room temperature; heating to 540~550 °C, holding for 4 hour, and cooling in air. Choosing this heat treatment process, the steel can get good coordination between strength and toughness. Analyzed by HREM, the steel had desirable microstructures, which were fine lath martensite matrix with high density dislocation and finely dispersed precipitate strengthening phase, and film-like reversed austenite precipitated from the boundary of martensite.

Abstract: The maraging steel are considered ultra-high strength due to its yield strength greater than 1400Mpa and are part of a set of advanced materials of interest for technological development, mainly for aeronautics and aerospace industry. For this purpose they should exhibit good toughness, fatigue resistance and acceptable weldability. Since the maraging steels are of higher cost we are intended to make the Medium Carbon Low Alloy Steel (MCLA) for the purpose of aeronautical and aerospace industry instead of Maraging steel as the cost of MCLA is comparatively less. An attempt is made to study on the basic properties of MCLA steels and Maraging steels by process modifications and comparing the results with that of the standard properties of the Maraging steel.

Abstract: This paper presents the results of mechanical properties study for samples of RIN-insulation material (Resin Impregnated Nonwoven – non-woven resin impregnated fabric) for high-voltage inputs at various temperatures, determined by three-point bending tests, impact strength tests and tensile tests with registration of test diagrams. The mechanical properties of RIN-insulation, which ensure working ability of the whole construction of high-voltage inputs, operating in difficult climatic conditions, are determined.

Abstract: The present work investigated the effects of Al, Si, and N content on the impact toughness of the coarse-grained heat-affected zone (CGHAZ) of Ti-containing low-carbon steel. Simulated CGHAZ of differing Al, Si, and N contents were prepared, and Charpy impact toughness was determined. The results were interpreted in terms of microstructure, especially martensite-austenite (M-A) constituent. All elements accelerated ferrite transformation in CGHAZ but at the same time increased the amount of M-A constituent, thereby deteriorating CGHAZ toughness. It is believed that Al, Si, and free N that is uncombined with Ti retard the decomposition of austenite into pearlite and increase the carbon content in the last transforming austenite, thus increasing the amount of M-A constituent. Regardless of the amount of ferrite in CGHAZ, its toughness decreased linearly with an increase of M-A constituent in this experiment, indicating that HAZ toughness is predominantly affected by the presence of M-A constituent. When a comparison of the effectiveness is made between Al and Si, it showed that a decrease in Si content is more effective in reducing M-A constituents.

Abstract: The structural features of epoxy polymer samples of different thicknesses under the influence of thermal energy are studied. The structure of fracture patterns of epoxy polymers, which are intensively structured in the thermal field, is investigated. The optimum temperature and duration of exposure are determined, which allows intensive production of products based on epoxy polymers with high physical and mechanical characteristics.