Bio-composites have gained significant attention within the aerospace industry due to their potential as a sustainable solution that addresses the demand for lightweight materials with reduced environmental impact. These materials blend natural fibers sourced from renewable origins, such as plant-based fibers, with polymer matrices to fabricate composite materials that exhibit desirable mechanical properties and environmental friendliness. The aerospace sector's growing interest in bio-composites originates from those composites’ capacity to mitigate the industry's carbon footprint and decrease dependence on finite resources. This study aims to investigate the suitability of utilizing plant derived flax fabric/PLA (polylactic acid) matrix-based bio-composites in aerospace applications, as well as the recyclability potential of these composites in the circular manufacturing economy.
The present study discusses about the determination of the Seal drag force in the application where elastomeric seal is used with metallic interface in the presence of different fluids. An analytical model was constructed to predict the seal drag force and experimental test was performed to check the fidelity of the analytical model. A Design of Experiment (DoE) was utilized to perform experimental test considering different factors affecting the Seal drag force. Statistical tools such as Test for Equal Variances and One way Analysis of Variance (ANOVA) were used to draw inferences for population based on samples tested in the DoE test. It was observed that Glycol based fluids lead to lubricant wash off resulting into increased seal drag force. Additionally, non-lubricated seals tend to show higher seal drag force as compared to lubricated seals. Keywords: Seal Drag, DoE, ANOVA
A typical high-pressure hose assembly consists of hose made with synthetic polymer braids and Teflon tube crimped with metallic fittings. These hose assemblies are mainly used for aircraft landing gear application considering its high-pressure sustenance and better flexibility. The proposed study investigates the effect of thermo-mechanical stress generated due to cyclic soaking and flexibility testing at thermostatic subzero (-65°F) and high temperature (+275°F) on performance of high-pressure hose assembly. This effect is further studied through hose tear-down which was envisioned to investigate the hose layer degradation and focused on changes in inner PTFE tube, which ultimately leads to product performance issues. Keywords: braids, tear down analysis, thermo-mechanical, inter-layer abrasion.
Nowadays, Bismuth (Bi) is being applied as an overlay material for engine bearings instead of Lead (Pb) which is an environmentally harmful material. Bi overlay has already been a solid performer in some automotive engine sectors due to its superior load carrying capacity and good robustness characteristic which are necessary to maintain its longevity during the lifetime of engines. The replacement is also seen on relatively larger size engines, such as Trucks and Off-highway heavy duty applications. Basically, these applications require higher power output than passenger cars, and the expected component lifecycle becomes longer. Even Bi has similar material characteristic with traditional Pb, it becomes challenging for the material alone to satisfy these requirements. Polymer overlay is known for its superior anti-wear performance and longer lifetime due to less adhesion against a steel counterpart than metal materials (included Bi).
Polyurethane foams (PUF) are a class of cellular polymers with a large range of applications. It is possible to control some properties of PUF by adjusting some chemicals, aiming to reach the best performance with lower cost, weight and process easiest. On the same way, graphene and its derivatives may be used for the modification of PUF, aiming to improve many properties. Depending on the dispersion technique, increases in mechanical, dynamical mechanical, thermal and acoustical properties may be reached, even when a low content of the nanomaterial is employed. This brief review presents some techniques used for the dispersion and incorporation of graphene and its derivatives into PUF, focusing on the enhancement of acoustical applications. Some techniques such as mechanical stirring, sonication and layer-by-layer are presented. It was observed that depending on the techniques, a real and significant difference was observed in some properties, mainly in acoustical
A natural fiber based polymer composite has the advantage of being more environment-friendly from a life cycle standpoint when compared to composites reinforced with widely-used synthetic fibers. The former category of composites also poses reduced health risks during handling, formulation and usage. In the current study, jute polymer laminates are studied, with the polymeric resin being a general purpose polyester applied layer-by-layer on bi-directionally woven jute plies. Fabrication of flat laminates following the hand layup method combined with compression molding yields a jute polymer composite of higher initial stiffness and tensile strength, compared to commonly used plastics, coupled with consistency for engineering design applications. However, the weight-saving potential of a lightweight material such as the current jute-polyester composite can be further enhanced through improvement of its behavior under mechanical loading.
To characterize the stress flow behavior of engineering plastic glass fiber reinforced polypropylene (PPGF) commonly used in automotive interior and exterior components, mechanical property is measured using a universal material testing machine and a servo-hydraulic tensile testing machine under quasi-static, high temperature, and high strain rate conditions. Stress versus strain curves of materials under different conditions are obtained. Based on the measured results, a new parameter identification method of the Johnson-Cook (J-C) constitutive model is proposed by considering the adiabatic temperature rise effect. Firstly, a material-level experiment method is carried out for glass fiber reinforced polypropylene (PPGF) materials, and the influence of wide strain rate range, and large temperature span on the material properties is studied from a macroscopic perspective.
This study delves into the dynamic properties of hybrid composite materials, specifically focusing on the natural frequency and modal damping characteristics of Jute Fiber-Rubber Particles Reinforced Polymer Composites (JRP) and Coir Fiber-Rubber Particles Reinforced Polymer Composites (CRP). Comprehensive experimental investigations were conducted utilizing an FFT analyzer. Initial experiments involved the preparation of specimens with varying rubber content, ranging from 2% to 5%. Jute, known for its cellulose-rich composition, was selected due to its innate damping properties, making it highly effective in mitigating vibrations. The primary motivation behind this research is to provide cost-effective solutions for reducing vibrations in mobility vehicles, addressing challenges associated with passenger comfort, durability, and overall performance. The study yielded promising results, with JRP exhibiting substantial reductions in vibrations, followed closely by CRP.
Plastic materials have advantages such as low specific gravity and excellent design freedom, so they are widely applied to automotive parts. However, mechanical properties of plastic materials change very sensitively to environmental temperature changes compared to metals, and mechanical properties decrease when exposed to high temperatures. Therefore, it is important to predict the performance of plastic materials and parts when exposed to a high-temperature environment in order to assure heat resistance quality under automotive environmental temperature conditions. In this paper, reliability analysis process to estimate the maximum service temperature of plastic parts was developed using aging data of material properties, environmental condition data of automotive parts, and field driving condition data.
This paper investigates the tire-terrain interaction for a Mixed Service Drive (MSD) truck tire with two different solid rubber material definitions using a Finite Element Analysis (FEA) virtual environment. An MSD truck tire sized 315/80R22.5 is designed with two different solid rubber material definitions: a legacy Hyperelastic Solid Mooney-Rivlin material definition and an Ogden Visco-Hyperelastic solid material definition. The popular Mooney-Rivlin is a material definition for solid rubber simulation that is not built with element elimination and is not easily applicable for thermal applications. The Ogden Visco-Hyperelastic material definition for rubber simulations allows for element destruction and is more suited for designing tire wear models. Both the Mooney-Rivlin and Ogden-equipped MSD truck tires are subjected to a static vertical stiffness test to validate their static domain characteristics.
Fast charging of traction batteries in passenger cars enables comfortable travel with electric vehicles, even over longer distances, without having to oversize the installed batteries in the vehicle for everyday use. As an enabling technology for fast charging, we would like to present the implementation of 2-phase immersion cooling at Kautex, where the traction battery serves as an evaporator in a refrigeration process. The 2-phase immersion cooling enables very high heat transfer rates of measured 3400 W/m^2*K and at the same time maximum temperature homogeneity within the battery pack at optimal battery operating temperature; Thus, charging rates of more than 6C can be safely and permanently maintained. We present the integration of this technology in a plastic battery housing, which we adapt in design to the requirements of a production in the injection molding process, to achieve readiness for serial production of the system.
Rubber isolators are widely used under random vibrations. In order to predict their fatigue life, a study on the fatigue analysis methodology for rubber isolators is carried out in this paper. Firstly, taking a mount used for isolating air conditioning compressor vibrations as studying example, accelerations versus time of rubber isolator at both sides are acquired for a car under different running conditions. The acceleration in time domain is transformed to frequency domain using the Fourier transform, and the acceleration power spectral density (PSD) is the obtained. Using the PSD as input, fatigue test is carried for the rubber isolator in different temperature and constant humidity conditions. A finite element model of the rubber isolator using ABAQUS is established for estimating fatigue life, and dynamic responses of the rubber isolator at frequency domain is calculated if a unit load is applied.
Issues and development needs in the field of NVH, one of the main performance of vehicles, have been constantly being discussed for a long time, and in recent years, as the fundamental structure of the automobile industry has changed from internal combustion engines to electric vehicles, the importance of NVH performance has been increasing. In the rapidly changing future environment of the electric and autonomous vehicle industries, in order to remain competitive, especially in the field of NVH, the vehicle NVH performance development work should be performed more quickly and concisely. However, through simulation analysis, it is necessary to expect a shorter development period and a lower cost. In the field of sound-absorbing parts and material analysis, there are many additional research points for improvement. In this study, porous foam materials, which are widely used as sound absorption parts materials for automobile interior materials, are used.
A systematic review based on the PRISMA protocol was used to evaluate compounds developed for 3D printing with the incorporation of cellulose nanofibrils into polymers to be used in the automotive sector. The processing parameters is a data of great relevance for the development of durable structural parts and this study was carried out using the state of the art on this subject. This way, the research was made using a search strategy from three different databases (Web of Science, Scopus and ScienceDirect) limiting studies between the years 2019 and 2023. The keywords used on these searches were: "3D Print" OR "FDM" OR "Fused Deposition Modeling" OR "FFF" OR "Fused Filament Fabrication" and "Natural Nanofiber" OR "Natural Nanofibril" OR "Cellulose Nanofiber" OR "Cellulose Nanofibril". The same criteria described were also used to search for patents on the PatentScope, Google Patents, and Espacenet platforms.
As we move toward electrification in future mobility, weight and cost reduction continue to be priorities in vehicle development. This has led to continued interest in advanced molding processes and holistic design to enable polymer materials for demanding structural applications such as pickup truck beds. In addition to performance, it is necessary to continue to improve styling, functionality, quality, and sustainability to exceed customer expectations in a competitive market. To support development of a lightweight bed design, a cross-functional team objectively explored the latest materials and manufacturing technologies for this application. In Phase 1 of this work, presented in 2022, the team considered a variety of alternatives for each functional area of the bed, including thermoplastic and thermoset materials with a range of processing technologies.
Additive manufacturing is currently being investigated for the production of components aiming for near net shape. The presence of chopped glass fibers with PA6 increases the melt viscosity and also changes the coefficients of thermal expansion and increase the heat resistance. The great dimensional stability obtained with the fusion of the PA6 with the fiber results in an extremely durable material even in adverse environments for many other materials used in 3D printing. PA6 is a material oriented for users who need to make structural parts and exposed to high mechanical stresses. The impact, test tensile, and flexural results for as-built PA6 with various infill patterns, including grid, triangle, trihexagon, and cubic, are tested.