Papers by Keyword: Impact Resistance

Abstract: Sabo soil-cement has the advantages of reducing the amount of sediment transported, reducing costs by using local sediment, and a zero-emission construction method. In addition, the strength development of Sabo soil-cement is based on the interaction between soil compaction and cement hydration. The strength can be determined based on the compressive strength obtained from uniaxial compression tests. However, dynamic loads, such as debris flows, are not evaluated. In this study, an impact loading experiment is conducted on a Sabo soil-cement specimen to examine the impact resistance. In addition, the relationship between the dropping weight accumulation energy and the collapsed volume and the relationship between the dropping weight energy and compressive strength are evaluated to determine the impact resistance of Sabo soil-cement. The results show that the greater the compressive strength, the greater the accumulated weight energy. In addition, there is a proportional relationship between the collapsed volume and dropping weight accumulation energy, and the relationship between the maximum impact load and weight energy increases linearly until cracks occur in the specimen. The impact spectrum of the specimen with a low compressive strength reduces the impact load on the collision surface. Therefore, if the compressive strength of the Sabo soil-cement is high, it has a high impact resistance against the impact load on the collision surface. On the other hand, if the compressive strength is low, Sabo soil-cement absorbs the impact force.

Abstract: This study investigates the impact resistance of 3D-printed polymers, including PLAWM, PLA, and ABS. ABS showed the highest impact resistance with an average damage area of 150 mm² and a standard deviation of 8 mm². PLA had moderate resistance, averaging 180 mm² with a 10 mm² standard deviation. PLA-WM exhibited the least resistance, with an average damage area of 220 mm² and a 15 mm² standard deviation—50% more than ABS and 22% more than PLA. These findings provide insights for optimizing 3D printing processes for high-durability applications.

Abstract: Shape memory alloys (SMAs) are smart materials that have the ability to recover large strain. The shape memory and superelasticity in these alloys is due to stress induced martensitic transformation that strongly depends upon the phase transformation temperatures. These alloys are being investigated for a number of applications due to their remarkable properties such as improved impact and damage resistance, vibration damping, seismic damping, shape morphing and crack closure properties. In this work, these alloys were integrated in fiber reinforced polymers (FRPs) to develop hybrid composite structures that can benefit from both fiber strength and intrinsic properties of SMAs resulting in weight efficient smart materials with better mechanical properties. The experimental investigation on impact performance of nitinol SMAs wire reinforced glass fiber composites (GFRP) showed 18% increase in toughness, as compared to steel wire reinforced glass fiber composites. In this paper, the effect of shape memory alloys wires in composite materials and their targeted applications especially for aerospace industry is presented.

Abstract: This study is an experimental study aims to examine the effect of utilization of straight, and low cost steel fibers on the impact resistance of concrete. The impact resistance of steel fiber reinforced concrete (SFRC) was assessed using drop weight test as per ACI committee 544. The steel fibers were randomly dispersed in concrete during mixing. Five mixes made with steel fibers dosages of 0% (control mix), 0.5%, 1%, 1.25% and 1.5% by volume of concrete were examined in the study. The results show that mixes containing steel fibers show better impact resistance than plain concrete (control Mix). The results also indicate that increasing the dosage of fiber increases the impact resistance of concrete but up to a certain content of fibers. The maximum increase was recorded at steel fiber dosage of 1.25% by volume of concrete. Also the patterns of failure of the concrete specimens show that fibers are very effective in increasing the concrete toughness which enhance the ductility of concrete and delays the crack initiation.

Abstract: Processes of modeling the optimal composition of structural epoxy composites filled with dispersed metal waste are investigated in the article. The influence character of dispersed metal wastes introduction on the operational and strength properties of cold-cured structural epoxy composites is shown. A model for predicting the operational and strength properties of structural epoxy composites depending on dispersed solid phase of metal waste content and a highly active accelerator in them is designed.

Abstract: Phase formation, impact resistance, and fracture surface were investigated in unreinforced Al6061, Al6061-5wt% fly ash and Al6061 hybrid composites containing 5wt% fly ash and 1,3 wt% CaO. The Al6061 composites were fabricated the stir casting process. The XRD patterns reveal the formation of second phases (MgAl₂O₄, CaAl₄O₇ and MgSiO₃), which were found in the Al6061 hybrid composites. The average grain size of Al6061 hybrid composite are much smaller than that of unreinforced Al6061.The impact resistance was enhanced by approximately 67% in Al6061 hybrid composite as compared to unreinforced Al6061 alloy. Brittle fracture indicting brittle fracture was observed in unreinforced Al6061 alloy while evidence of a mixture of brittle and ductile fracture was found in the Al6061 hybrid composites.

Abstract: This study also investigates the effectiveness of multiple surface modification of recycled concrete aggregate (RCA) with respect to mechanical properties of the resultant recycled aggregate concrete (RAC) when exposed to various curing conditions, namely, normal water (N_w) and seawater (S_w). The properties included compressive and flexural strength and impact resistance. Findings show that effect inclusion of the treated coarse RCA is significant in enhancing the mechanical properties of RAC. The exposure to S_w appears to affect the degradation of the compressive strength of RAC remarkably in a marine environment. In this case, however, using of treated RCA is found beneficial in decreasing the deterioration in the compressive strength of RAC.

Abstract: In this paper, a complex study of composite materials of different nature for the presence of internal defects after the application of impact damage was carried out. The dependence of the initiation energy on material damage from the magnitude of the impact energy is obtained. The areas of sample bundles were investigated by ultrasonic testing (UT). The structure of samples from composite materials was monitored using an industrial microtomography system. A technique was developed that allows highly accurate determining the size of internal sample defects by means of computed tomography (CT).

Abstract: There are shown studies on influence of film-forming components on the corrosion resistance of powder coating. Protective and decorative powder coatings - one of the most promising types of paints and varnishes for industrial use. Their main advantages are: absence of solvents, practically waste-free coating technology (the degree of powder utilization during application is close to 100 relative simplicity and cost-effectiveness of the production process of coating. The study of protective properties of powder coatings is associated with the detection of high performance properties and high corrosion resistance of the material. Although corrosion resistance of powder coating performance continues to improve via the design of more effective film-forming components the nomenclature of which is wide enough.

Abstract: Hybrid metal matrix composites are being widely investigated for use in light weight, high strength applications. In the present study, Aluminium alloy Al7075 was reinforced with B₄C and TiO₂ at 4% and 2% weight fractions respectively. The powders of the reinforcements were ball milled for uniform distribution in the Al matrix, and later fabricated by stir casting technique primarily due to simplicity and economy of the method. The specimen were prepared as per ASTM standards and later subjected to hardness, double shear, wear and impact tests and the results were compared with that of pure aluminium specimen fabricated by the same method. The hardness, shear strength, impact strength of the composite were found to be higher than pure aluminium by 4.97%, 32.28% ands 6.41% respectively.