Papers by Keyword: Mechanical Testing

Abstract: For the single-particle erosion of an iron target under low impact angles, normal impact mechanism and tangential cutting mechanism operate through a synergistic interaction yet also compete with each other, each demonstrating distinct emphases. Their relative roles under varying low-incidence angles are worth studying. In this paper, physical experiments of single-particle erosion are conducted on an iron target by impingement of an Al₂O₃ particle at an impact velocity of 120 m/s and impact angles of 30, 20 and 10 degrees. Results show that tangential cutting dominates the penetration stage for three degree cases. However, normal impact also plays a relatively important role during the penetration stage at 30º. Normal impact dominates the critical stage between penetration and rebound for all three low incident angles, but its influence is weaker at 20º and 10º compared to 30º. Normal impact dominates the rebound stage at 30º, while tangential cutting dominates the rebound stage at both 20º and 10º. Additionally, the influence of normal impact is more pronounced at 20º than at 10º during the rebound stage.

Abstract: In this work, jute and bamboo fiber is used as reinforcement to prepare hybrid composites. The alkali treatment of both the fibers are carried out and the strength of composites prepared with the alkali treated fiber is compared with the composites made from untreated fibers. The bamboo fibers are chopped and pulverized and added to matrix while the jute fiber is used in continuous form. Tensile, flexural, impact, hardness, thermal absorptivity test is carried along with the flammability test. The tensile strength of jute –bamboo-epoxy composite (JBEC) with untreated fibers is observed to be 12.21 MPa while the tensile strength of jute-epoxy composite (JEC) with untreated fiber composite is observed to be 11.72 MPa. Further, the alkali treatment of fiber increases the tensile strength of both the JEC and JBEC by 8%. About 11.12% rise in tensile strength in JEC and 14.35% rise in JBEC is observed due to alkali treatment of fibers. JBEC with alkali treated fibers [JBEC(AT)] shows 42.5HV hardness, while JBEC shows the hardness of 40.2HV. The hardness of JEC increased from 31.3HV to 35.5HV due to alkali treatment. JBEC and JEC with alkali treated fibers [JBEC(AT), JEC (AT)] shows higher thermal absorptivity than JBEC and JEC owing to the fact that higher thermal conductivity of bamboo fibers. The JBEC(AT) shows an ignition temperature of 301°C, while JBEC starts burning at a temperature of 285.6°C. JEC starts burning at 256.56°C and JEC burns by 248.52°C.

Abstract: Nowadays, there is a spike in 3D printing and additive manufacturing technology all over the world. Starting from the prototype state to the final production process, a high demand is noticed due to the fact that this technology is rapid, economical and good-fit for finding out the mechanical behavior of the material and the structure. Thermoplastic polyurethane (TPU) is widely used in automotive industry, sport industry, medical industry, even in footwear industry. High abrasion resistance, shear strength, elasticity with low-temperature performance make TPU widely used and so important. In this study, we focused on the effect of infill pattern and density in mechanical behavior of 3D printed TPU part. We controlled the density and pattern both resulting in changing mechanical properties, helping us reduce the use of material, cost and production time accordingly. It is necessary to prepare a database on the test results, which can help us to understand the parameters related to internal structure or infill pattern of the material.

Abstract: This paper delves into further analysis of the best infill structure for mechanical applications in 3D printing. Infill plays a crucial role in determining the strength, weight, and overall mechanical properties of printed objects. This study aims to explore and evaluate different infill structures to identify the optimal choice for mechanical applications. Specifically, the focus is on investigating the gyroid infill pattern due to its unique properties and potential advantages. The research includes an assessment of the structural integrity and mechanical performance of objects printed with gyroid infill compared to other commonly used infill patterns. Experimental testing, including tensile strength and load-bearing capacity, will be conducted to quantify and compare the mechanical properties of the printed parts. The results of this study will provide valuable insights and guidance for selecting the most suitable infill structure in mechanical applications, contributing to enhanced design and manufacturing capabilities in the field of 3D printing.

Abstract: This study aims to represent an approach for transferring the materials testing datasets to the digital schema that meets the prerequisites of the semantic web. As a use case, the tensile stress relaxation testing method was evaluated and the testing datasets for several copper alloys were prepared. The tensile stress relaxation testing ontology (TSRTO) was modeled following the test standard requirements and by utilizing the appropriate upper-level ontologies. Eventually, mapping the testing datasets into the knowledge graph and converting the data-mapped graphs to the machine-readable Resource Description Framework (RDF) schema led to the preparation of the digital version of testing data which can be efficiently queried on the web.

Abstract: Within the technologies that make up Additive Manufacturing (AM), one of the ones that have taken the greatest prominence in recent times is DED (Direct Energy Deposition), particularly that of wire feedstock. The W-DED/LB technique has some benefits compared to other AM methods, such as the fabrication of relatively larger parts, repair capabilities of the damaged areas of a component, cladding of different materials on existing parts, and reduced material waste.This study describes the optimisation of processing parameters for the manufacturing stainless steel (SS316L) and Inconel 718 alloys (INC718) using W-DED/LB. This is performed by modifying processing aspects like deposition trajectories, laser power, displacement speeds of the DED head, etc, with the aim of obtaining high deposition rates and a density above 99.5%. Once the alloy systems are optimised, a characterisation campaign has been performed, which includes a series of tests as well for defectology analysis using X-ray Computed Tomography (CT). Finally, the influence of different heat treatments on the tensile behaviour is analysed.This work has developed the technology of DED assembling in a Kuka-robot, so the challenge has not only been to control the DED system, but also the communication with the robotic arm to guarantee perfect harmony between all the parts that make up the W-DED/LB system.

Abstract: This paper aims to analyse in detail a structural support steel beam from the years 1920 which has been in-use since then. Some tests will show that the steels from the analysed beams are not consistent, which given the time it was manufactured it does make sense since the metallurgy was not nearly as developed as it is now. It will present the analysis of the beam’s chemical composition; tensile and impact properties as well as the hardness of the material.

Abstract: Using austenitic steel in welding structures requires both destructive and non-destructive testing (NDT) to approve the use of intended welding specification, but also testing of material properties, even if they are guaranteed by manufacturer. In this particular case, X2CrNiMo17-12-2 (commercial trademark AISI 316L) is the material that has to be partly replaced by NiCr21Mo (commercial trademark Incoloy 825) in a piece of process equipment exposed to elevated temperature and highly corrosive environment. This research presents an investigation of overmatching V groove welded joint made of these two austenitic steels. Due to materials properties and specific application conditions, low heat input TIG welding was utilized. Mechanical properties of welded joint have been examined to check criteria which guarantees safe work and integrity of welded components. Chemical composition of used filler material was close to the one of NiCr21Mo alloy, providing weld overmatching, which needs to be checked as well. Mechanical testing (tensile, bending, impact, hardness), macro-and microstructure analysis provided detailed insight into welded joint characteristics and a ground for further investigation concerning heterogeneous austenitic welded joint, taking into account overmatching effect.

Abstract: To meet the demands of higher speeds, higher power density and the ability to adapt to harsh operating environments over a long period of time, structural designers use various materials to fabricate rotor parts for turbine assemblies. This introduces high requirements for stable rotation and rotor life. It is therefore important to analyse and determine the mechanical properties for a turbine rotor taking into account the manufacturing process. This paper focuses on laboratory mechanical testing for determination and analysis of turbine components consisting of a rotor, from 42CrMo4 (DIN EN 10083-3) and a turbine, made from Inconel 713C in laser welded assembly. The tests carried out consists of tensile testing for the turbine – rotor assembly, microhardness measurements, macro and microscopic examinations of the welded joint. The obtained results stand as a validation for the welding process technology used for this type of application ensuring the superior mechanical characteristics required for operation in harsh enviornments.

Abstract: In the modern world, the difficulty of manufacturing has gradually decreased by many new technologies. 3D printing is one of those technologies which completely improved the flexibility of manufacturing to overcome any complex design where any complex part can be manufactured using different types of 3D printers with different materials indeed. 3D printers are differentiated by materials FDM is one of the 3D printers used to print plastic and composite materials. A CAD design is converted into STL file and sent to slicing software to check any tessellation errors. Component is then fed into MakerBot software to check for proper orientation and changing the printing parameters. 3D printers also have input parameters like conventional manufacturing process, which have high impact on the printed part. In this paper we mainly focused on Input parameters like printing temperature, layer thickness, raster angle is changed using Taguchi method to observe the changes in the material properties.