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Crash boxes are safety elements generally made of metallic materials and mounted on the chassis of vehicles to prevent possible injuries to driver and passengers by absorbing the energy generated during a collision and ensuring integrity of vehicle. In order to save fuel and reduce harmful gases released into the environment, the proportion of metallic materials used in vehicles is decreasing and being replaced by composite materials. While composite materials are as durable as metallic materials, they are preferred because they are lighter. In this study, circular composites consisting of glass (S1), aramid (S2), carbon (S3), and hybrid combinations of aramid‐carbon‐glass (S4), carbon‐glass‐aramid (S5), and glass‐aramid‐carbon (S6), all with epoxy resin matrices, were produced using the vacuum infusion method and investigated. Crush parameters, maximum peak loads and specific energy absorption of hybrid tubes with different fiber types and winding order were compared. S3 tube had the best energy absorption performance among all samples of 257.288 Joules, while the worst energy absorption performance was obtained for S2 tube with 30.944 Joules. Among the hybrid samples, the best result was determined as 166.50 Joule with hybrid S5. Although the energy absorption capacities of hybrid composite tubes were close to each other, they had lower results for energy absorption and specific energy absorption than S1 and S3. For specific energy absorption, as with energy absorption, the best result was obtained with S3, while the lowest result was obtained with S2. Highlights: The aim of this study is to evaluate the performance of composite crash boxes.The effect of fiber type and hybridization was examined.Specific energy absorptions and maximum contact forces were compared.Cylindrical samples were produced by vacuum infusion.The variation of damage depending on fiber type was investigated. [ABSTRACT FROM AUTHOR]

Nanoparticles are used in many areas related to composite materials. Recently, the importance of nanoparticle‐reinforced materials in advanced technology has been gradually increasing. In this study, epoxy reinforced with various nanoparticles, and neat epoxy were used to produce woven composites. The fatigue behaviors of woven composites reinforced with various nanoparticles under tension‐compression fatigue loads were investigated. The tensile and fatigue strengths of woven composites enhanced with nanoparticles were compared with woven composites without nanoparticles. Tensile tests showed that the woven composites reinforced with nanoparticles were damaged at high loads. Fatigue tests revealed that the woven composites reinforced with nanoparticles exhibited high cycle numbers. Adding 0.5%, 1%, and %3 nano‐CuO to epoxy increased the cycle numbers of the woven composites by 25%, 67%, and 75% respectively at 60% load level. The failure mechanisms of woven type composite materials were investigated by scanning electron microscopy (SEM). Fiber fractures and delamination damages of samples were observed. [ABSTRACT FROM AUTHOR]

Abstract In this study, single lap joints were formed by adding nano-Al 2 O 3 , nano-TiO 2 and nano-Al 2 O 3 powders in various proportions to the epoxy adhesive and using the additive-free epoxy adhesive; and also the mechanical properties of the connections were experimentally investigated at 20, 25, 30, 50 and 70 mm overlap lengths under shear load. In the experimental work, DP460 epoxy adhesive was used as adhesive and AISI 304 stainless steel plate as adherent material. When the results obtained from the experiments were examined, it was revealed that the average damage load in connection with the use of nanoparticle-added adhesives increased considerably in general. As a result of the experiments, the most effective nanoparticle in increasing the failure strength of the adhesive joints with nano-Al 2 O 3 particles and the maximum failure strength increase rate was 20 mm in overlap length and 97% in 4 wt% nano-Al 2 O 3 reinforced specimens. It was also found that the nanoparticle strain was an important parameter in the tensile strength of the adhesive joints. In addition, it has been found that the addition of nanoparticles into the adhesive increases the elongation of the joints. When the adhesion surfaces of the samples were examined as in the case of plain adhesives, damage was observed as adhesion separation while nanoparticle reinforcement was observed as a mixture of adhesion and cohesion. Graphical abstract Image 1 Highlights • Behaviour of nano-particle used in the adhesive joints was analyzed by experimental. • The effects on the tensile strength of nano-particles were investigated in single lap joints added nano-particle. • Three type nano-particles are used to mix with adhesive. • Experimental analyses were carried out to predict the failure loads. • The maximum failure strength increase rate was 20 mm in overlap length and 97% in 4 wt% nano-Al 2 O 3 reinforced specimens. [ABSTRACT FROM AUTHOR]

Abstract Because of their many advantages, adhesively bonded joints are intensively used in many engineering fields. So, the mechanical research of the adhesively bonded joints is very important to use these joints safely. There are many studies performed by researchers to investigate the mechanical properties of the adhesive joints. There has been a considerable interest in nanoparticles added to structural adhesives recently because nanoparticles improve the mechanical properties of adhesives and joints. In this paper, different nanoparticles reinforced by epoxy adhesive, and neat adhesive were used to produce single lap joints. The static and fatigue strengths of single lap joints incorporating nanoparticles were compared to those without nanoparticles. Experiments were performed at 20 mm overlap length. DP460 epoxy was used as the adhesive material, and nano-Al 2 O 3 , nano-TiO 2 and nano-SiO 2 were used as the nanoparticles; and AISI 304 stainless steel plates were used as the adherents. The results of the experimental research revealed that average failure load increased significantly in nanoparticle-reinforced adhesive joints. The highest average failure load was obtained with 4 wt% nano-Al 2 O 3 in epoxy adhesive. Fatigue tests were performed at 10 Hz frequency, and 0.1 loading ratio (R). When the fatigue test results were examined, it was observed that the addition of the nano-Al 2 O 3 and nano-SiO 2 to the adhesive increased fatigue strength of the adhesive joints, on the other hand, the addition of the nano-TiO 2 to the adhesive reduced fatigue strength of the adhesive joints. Graphical abstract Image 1 Highlights • Behavior of nano-particle used in the adhesive joints was analyzed as experimental. • The effects of nano-particles were investigated in the single lap joints on the static and fatigue strength. • Three type nano-particles are used to mix with adhesive. • The highest average failure load was obtained with 4 wt% nano-Al 2 O 3 in epoxy adhesive. • It was observed that the addition of the nano-Al 2 O 3 and nano-SiO 2 increased fatigue strength of the adhesive joints. [ABSTRACT FROM AUTHOR]

In this study, the effect of the adherend width on the tensile strength and the failure load of Z joints was analyzed both experimentally and numerically using two adhesives with different properties. Atlac™ 580 and Flexsotix™ were used as adhesives, and adherends were prepared with two different composite materials. To identify the mechanical properties of the adhesives, the bulk specimen method was used. Then, the Z joints were prepared using the aforementioned adhesives. The Z joints were subjected to tensile loads in the experiments. The stress analyses were performed using a three-dimensional finite element method (3D FEM). The 3D FEM analyses were performed with ANSYS (10.0). The 3D FEM analyses were performed to investigate the stress distributions in the adhesive layers in the Z joints. The numerical results compared favorably with the experimental results, and were found to be quite reasonable. The results showed that the joint strength increased when the specimen width (b) was increased. To maximize the performance of the joint for either adhesive, b = 15 mm was found to be the most suitable value for the width. [ABSTRACT FROM PUBLISHER]

Abstract: In this paper, the mechanical behavior of the scarf lap joints (SLJs) bonded with adhesive (Vinylester Atlac 580) under a tensile load was analyzed. The effects of scarf angle at the interface strain distributions of SLJs were examined. The stress analyses were performed via three dimensional Finite Element Method (3D-FEM). The 3D-FEM code employed was Ansys (12.0). Experimental results were compared with the 3D-FEM results and were found quite reasonable. The results indicated that the maximum values of the normalized εx strain values were determined at θ =60° in all joints. [Copyright &y& Elsevier]

In this experimental work, raw cottonseed oil was converted by KOH-catalyzed transesterification reaction with methyl alcohol to the cottonseed oil methyl ester (biodiesel) and then tested in a single cylinder, four strokes and direct injection diesel engine at the constant engine speed (2000 rpm) under different engine loads. The composition and the fuel-related properties of produced biodiesel were determined by using gas chromatography (GC) and related instruments. An increase in brake specific fuel consumption (BSFC) and decrease in brake thermal efficiency (BTE) for fuel blends were observed compared with diesel fuel. Compared with diesel fuel, exhaust emissions were found to be lower in carbon monoxide, hydrocarbon, nitrogen oxides and smoke with the use of fuel blends. It was concluded that cottonseed oil methyl ester-diesel fuel blends could be substituted for the diesel fuel without any modifications in diesel engines, with better environmental characteristics of fuel blends. [ABSTRACT FROM AUTHOR]