Evaluation Of Mechanical Performance Research Articles

Evaluation of Key Performance of Aircraft Fabric Rubber Seal During Flight

In this Paper, the mechanic properties and sealing performance of the aircraft fabric rubber seal during flight are studied. First, the mechanic parameters, geometric structure, loading method of different aircraft cabin door fabric rubber seals, and gas conditions are analyzed. Second, the modified gas leakage rate formula of fabric rubber seal within wide ranges of temperature and gas pressure is derived based on the previous gas leakage rate formula of fabric rubber seal and the gas leakage rate experimental results. Then, the gas leakage rate prediction method of multicontact sealing surfaces is established. Finally, the variation law of the aircraft gas leakage rate with the altitude are determined based on the configuration number of the aircraft fuselage doors and the finite element results of the aircraft door seals. The research results will provide reliable scientific guidance for the mechanical performance evaluation and sealing performance prediction of fabric rubber seals.

Compatibility effect of r-ABS/r-HIPS/r-PS blend recovered from waste keyboard plastics: evaluation of mechanical, thermal and morphological performance

The primary aim of this study was to identify the polymers recovered from keyboard waste, and formulate a ternary blend from the recovered polymers, with improved mechanical, thermal and morphological characteristics, and encouraging product-based recycling. The recycling and reuse of polymers recovered from E-waste is one of the prime topics in solid waste management. The major drawbacks of utilizing recycled polymers are its lower mechanical strength. This was majorly evidenced in styrene based polymers such as acrylonitrile butadiene styrene (ABS) and high impact polystyrene (HIPS). In our case, the polymers ABS, HIPS and polystyrene (PS) were recovered from waste keyboards, and their impact strength was 29 J/m, 42 J/m and 20 J/m respectively. After formulating a ternary blend with PS as a major phase, the impact strength observed was 66 J/m. The thermal stability of the blends also improved from 380℃ to 396℃, after the addition of PS to the blends, but the glass transition temperature had negligible effect. The morphology of ternary blend shows salami structures after the addition of ABS/HIPS blends. This shows that the r-PS morphology had a brittle to ductile transition which leads to the improvement of impact properties.

Evaluation of mechanical performance on a developed AA 6061matrix-Mg/0.9-Si/0.68 reinforced with B4C based composites

Aluminum matrix composites are chosen for electronic, aircraft, and automobile components due to the lightness of their weight and high specific strength. High-quality aluminum-based composites are well known for their microhardness and high refractoriness performance in aerospace with the advantage of structural applications. The boron carbide ceramic as a reinforcement plays an outstanding function in the base matrix to enhance the mechanical behavior of the composites. The present effort revealed that the synthesized composites were fabricated by the stir casting process and B4C having a particulate size of 50 µm were reinforced from 1% to 15% in the AA 6061 by varying weight percentages. Microhardness such as Brinell and Rockwell hardness moreover impact testing was performed experimentally. The mechanical characterization of fabricated composites with high mechanical performance-based composites has been investigated in this research work. Using microstructural characterization by scanning electron microscopy and x-ray diffraction we examinded high mechanical performance-based composites.

The Mechanical Performance evaluation of Vertical Stability Coil under Electromagnetic-structure Coupling Analyses

The vertical stability coil is a set of active feedback control coil that is used to deal with the vertical instability of plasma. To improve the response performance, the coil is mounted in the vacuum vessel, which denotes the coil-body will suffer from large electromagnetic force from the plasma current and poloidal field coils. Besides the current flowing in the feeder is nearly perpendicular with magnetic field originated from toroidal coil. It implies large electromagnetic force will be generated on the feeder. In order to withstand the impact from the electromagnetic force, a series of reinforce compo-nents are designed and installed on the coil. It is necessary to verify whether or not the coil conductor and auxiliary components could successfully bear the shock of large electromagnetic force. A three-dimensional magnetic field model is built to accurately calculate the magnetic field and electromag-netic force. Corresponding to the magnetic field calculation model, a more detailed me-chanical anal-ysis model is created to launch the electromagnetic-structural coupling analysis. Based on the stress analysis results, the local structure of the coil is optimized to decrease the peak stress. The updated model is reanalyzed and stress linearization is exerted to extract the different kinds of stress on the coil components. Finally, the stress is evaluated based on ASME analytical design. The evaluation result is helpful to guide the further design optimization.

Comparative evaluation of mechanical properties and shaping performance of heat-treated nickel titanium rotary instruments used in the single-length technique.

This study aimed to evaluate the mechanical properties of contemporary heat-treated nickel-titanium (NiTi) rotary instruments used in the single-length technique [ProTaper Next (PTN), HyFlex EDM (EDM), and JIZAI (JZ)]. Bending loads, cyclic fatigue resistance, torque/force values and canal-centering ratios were evaluated for the three instruments and a non-heat-treated experimental NiTi instrument with the same geometry as JZ (nJZ). EDM and JZ exhibited significantly lower bending load and more cycles to failure compared with nJZ and PTN (p<0.05). PTN and JZ exhibited significantly better centering ability than nJZ and EDM (p<0.05). JZ and nJZ generated significantly smaller upward force and maximum torque than PTN and EDM (p<0.05). Under the present experimental condition, JZ exhibited flexibility and cyclic fatigue resistance comparable to EDM, better maintained the canal curvature than the other instruments, and generated smaller torque and screw-in force than PTN and EDM.

Molecular Mechanism and Absorption Performance Evaluation of CO2 Capture from the PCC Process by Monoethanolamine-Based Deep Eutectic Solvents

In the field of green chemistry, deep eutectic solvents (DESs) and their applications have always been a research hotspot. In this work, the absorption performance of CO₂ in DESs is studied by molecular dynamics(MD) simulation and process simulation. The microbehaviors of hydrogen bond acceptors (HBAs)/ hydrogen bond donors (HBDs) and DES/H₂O are studied by MD simulation. Through the analysis of interaction energy, radial distribution function, spatial distribution function, and diffusion coefficient the potential relationship between the absorption effect and molecular structure and aggregation characteristics is clarified. The key factors such as absorption mechanism and regeneration ability under various conditions are discussed. Because the high viscosity of DES hinders its commercial application, we studied the effects of temperature and water on the viscosity and absorption capacity of DES. After comprehensively considering the diffusion coefficient and the interaction energy, we recommend the use of 10% DES in industrial applications. In industrial applications, increasing system temperature has a more positive effect on ChCl/monoethanolamine (MEA) viscosity than adding water. The CO₂ removal process of MEA-based DESs is modeled and simulated using Aspen Plus. The feasibility and development trend of carbon dioxide capture is evaluated by sensitivity analysis. The CO₂ capture rate (RCO₂) is 99.03%, and the CO₂ purity in the product gas (PCO₂) is 99.06%. Global warming potential and eutrophication potential are considered. Compared with the traditional MEA process, this process has obvious advantages in product yield and environmental pollution. This work provides a technical reference for the realization of more efficient and environmentally friendly solvents in industrial applications. It will help industries such as coal and electricity to achieve low carbon emissions and promote sustainable development.

Assessing the use of finite element analysis for mechanical performance evaluation of intervertebral body fusion devices.

BackgroundIntervertebral body fusion devices (IBFDs) are a widely used type of spinal implant placed between two vertebral bodies to stabilize the spine for fusion in the treatment of spinal pathologies. Assessing mechanical performance of these devices is critical during the design, verification, and regulatory evaluation phases of development. While traditionally evaluated with physical bench testing, empirical assessments are at times supplemented with computational models and simulations such as finite element analysis (FEA). However, unlike many mechanical bench tests, FEA lacks standardized practices and consistency of implementation.ObjectivesThe objectives of this study were twofold. First, to identify IBFD 510(k) submissions containing FEA and conduct a comprehensive review of the elements provided in the FEA reports. Second, to engage with spinal device manufacturers through an anonymous survey and assess their practices for implementing FEA.MethodsFirst, a retrospective analysis of 510(k) submissions for IBFDs cleared by the FDA between 2013 and 2017 was performed. The contents of FEA test reports were quantified according to FDA guidance. Second, a survey inquiring about the use of FEA was distributed to industry and academic stakeholders. The survey asked up to 20 questions relating to modeler experience and modeling practices.ResultsSignificant gaps were present in model test reports that deemed the data unreliable and, therefore, unusable for regulatory decision‐making in a high percentage of submissions. Nonetheless, the industry survey revealed most stakeholders employ FEA during device evaluation and are interested in more prescriptive guidelines for executing IBFD models.ConclusionsThis study showed that while inconsistencies and gaps in FEA execution do exist within the spinal device community, the stakeholders are eager to work together in developing standardized approaches for executing computational models to support mechanical performance assessment of spinal devices in regulatory submissions.

The Incubation Mechanism and Incubation Performance Evaluation of &amp;quot;Co-creation Space&amp;quot; in Colleges and Universities

The construction of "co-creation space" in colleges and universities has created a comprehensive support platform for their students to start their own businesses, and plays an important role in implementing the innovation-driven development strategy of the country. However, china's " co-creation space " in colleges and universities started relatively late, the law of business incubation has not yet been clarified, the entrepreneurship incubation mechanism, performance evaluation and other research is relatively weak, indirectly affecting the practice of innovation and entrepreneurship guidance. The purpose of this paper is, through the study of the incubation mechanism and performance evaluation of the university's co-creation space, to provide some reference for better use of the superior resources of colleges and universities to improve the incubation efficiency and improve the quality of the incubation of the “co-creation space”. This paper analyzes the meaning of " co-creation space " and the function of incubation service in colleges and universities, and expounds the mechanism of the incubation capacity of the university's creation space, that is, the cultivation mechanism of the spirit of creation, the nesting mechanism of the entrepreneurial network, the mechanism of heterogeneous synergy of entrepreneurship, the mechanism of upgrading the incubation capacity and the interrelated role between them. Based on the meaning of the incubation mechanism of "university co-creation space", the influence factors of incubation performance are extracted, and the evaluation index system of incubation performance of "creation space" in colleges and universities is constructed on this basis. And designed a set of operational evaluation procedures. Data sources are obtained by means of questionnaires and interviews, respectively. using the scoring method of Licht's five-point scale, the incubation performance of selected case universities was tested and evaluated, the evaluation scores were obtained, and the corresponding evaluation results were determined by reference to other evaluation criteria. Reasonable suggestions are put forward for the problems found in the evaluation.

Design, performance evaluation and investigation of the dynamic mechanisms of earthworm-microorganisms interactions for wastewater treatment through vermifiltration technology

The study brings insight to earthworms-microorganism's symbiotic interactions for wastewater treatment for the most essential mechanisms (antimicrobial and enzymatic activity) during vermifiltration. The results showed that vermifilter (VF) resulted in effluent with biochemical oxygen demand (BOD) <5 mg/L, chemical oxygen demand (COD) <30 mg/L, coliforms <103 MPN/100 mL, signifying higher treatment efficacy. The study reported the microbial community diversity for influent, effluent, filter media, earthworm's body, casts and its coelomic fluid to understand the correlations & symbiosis to decipher the mechanisms. The results further showed that earthworm body were dominated by Gammaproteobacteria, and the percentages arrived to 60% of the microbial species, while VF showed presence of Firmicutes and Actinobacteria, which signifies that earthworms had a profound effect on controlling microbial biomass and improving microbial activity. The protein profiling of the bacteria associated with VF showed that earthworms feeding and earthworm–microorganisms interactions were responsible for enhanced treatment performance.

Hot isostatic pressing of a near α-Ti alloy: Temperature optimization, microstructural evolution and mechanical performance evaluation

Hot isostatic pressing (HIP) shows distinct advantages in the manufacture of difficult-to-process materials into components with geometric complexity and high mechanical performance. In this work, a near-α titanium alloy Ti–6Al–2Zr–1Mo–1V (TA15) designed for service temperatures of ~500 °C in the aerospace industry was processed by HIP at three representative temperatures. A systematic study on the phase constitutions, microstructural evolution, and tensile properties measured at 20, 500, 600, and 700 °C was carried out for the assessment of HIP TA15 specimens. The relationships among HIP temperature, crystallographic characteristic, and mechanical performance of HIP TA15 were elucidated in detail. Spark plasma sintering (SPS) was selected to compare with the HIP technique regarding the fabrication of TA15 alloy. The tensile strength and ductility of the HIP specimens at 500 °C were 14.8% and 52.8% higher than those of the SPS counterparts. Furthermore, the high-temperature tensile properties of HIP TA15 specimens were comparable to those of the forged IMI 685 and even better than those of sintered Ti60 parts. These findings can serve as a guideline for the HIP process of TA15 alloy and the HIP parameter optimization for other near-α Ti alloys applied in harsh environments.

Evaluation of Mechanical and Durability Performance of Coir Pith Ash Blended Cement Concrete

India is one of the prominent producers of coconuts in the world. Along with the desired products, many undesirable by-products are also generated from the coconut and coir industry. Among the various by-products, coir pith and short coir fibres are the major ones and are obtained during the extraction of long coconut fibres. Raw coir pith was heated in a metallic vessel at 450 ℃ to obtain coir pith ash. In this study, the impact of the presence of CPA as a supplementary cementitious material, on the various mechanical and durability parameters are taken into consideration. The various parameters considered for assessing the mechanical performance include compressive strength, split tensile strength, flexural strength and Ultrasonic pulse velocity. Water absorption and resistance to sulphuric acid environments were considered to evaluate the durability of CPA blended concrete. The resistance of CPA blended concrete against sulphuric acid environment was evaluated by considering the variation in weight, water absorption and percentage loss in compressive strength. Five concrete mixes were used for the study with CPA content ranging from 0% to 20%. Indian standard method of concrete mix design with water-cement ratio 0.45 was adopted. To understand the effect of change in water-cement ratio on the durability parameters of concrete, the study also considered other water-cement ratios like 0.40 and 0.50. Results indicated that the mechanical and durability performance improves when CPA is used as supplementary cementitious material. Also, the specimens with water-cement ratio 0.40 performed better than other ratios.

Mechanical and tribological performance evaluation of maleic anhydride grafted ethylene octene copolymer toughened acrylonitrile butadiene styrene/polyamide 6 composites strengthened with glass fibres

Maleic anhydride grafted ethylene octene copolymer toughened acrylonitrile butadiene styrene/polyamide 6 composites, strengthened with varying amounts of E-glass fibre (EG) were successfully developed via compounding technique. The tribological investigations of compounded composites support excellent wear resistance potential of glass fibre, with 15 wt% EG reinforced composites displaying ∼10 times superior wear resistance. While, mechanical performance evaluation validates the strengthening abilities of EG, with tensile strength and tensile modulus displaying a substantial improvement. The microstructure of worn composite surfaces, characterised by scanning electronic microscopic studies suggest the inherent ability of glass fibre in PA6 matrix to enact the role of reinforcements by choice.

Evaluation of Mechanical and Wear Performances of Natural Fiber Reinforced Epoxy Composites

ABSTRACT The possible usage of natural fiber reinforced composites (NFC) for various industrial applications is being explored. In the present work, mechanical and wear behavior of three different NFCs were analyzed. Natural fibers like prosopis juliflora (PJ), abuliton indicum (AI), and tapsi (T) fibers in the form of straws were considered in the present study. Composites were fabricated for three different fibers with 20 wt.% by hand layup method. Mechanical tests like tensile, flexural, and impact were performed along with tribological tests. Tensile and flexural were performed on universal testing machine, impact on izod impact tester, and wear test on pin-on-disc test setup. Wear tests on the fabricated composite samples were performed with varying the process parameters like sliding speed and applied load with a maximum sliding distance of 3000 m. SEM analysis was also performed on the fractured and worn out samples to know the bonding behavior, failure, and material removal mechanism of three NFCs. Among all the NFCs, prosopis juliflora fiber attained an improved mechanical and wear behaviors when contrasted to the other two NFCs.

Process Simulation-Based Design, Mold Construction and Mechanical Performance Evaluation of an Insert-Injection Molded Thermoplastic Polyurethane Part

Abstract This paper presents a case study of simulation-based design and experimental validation of the insert-injection molding process of a complex polyurethane part. The part under consideration is a dowel holder which is a machine element used in the concrete railway sleepers production. A simulation study was carried out to define the relevant mold design options and optimal molding parameters as well as to evaluate their influence on the part's quality indexes. Simulation was performed using the software Moldex3D. The mold was constructed according to the optimization analysis and a batch of pieces was manufactured under the optimized conditions. A mechanical testing experiment – representing the actual service loading conditions – was designed and performed to validate the mold and process designs and the part performance. Simulation and statistical analysis results allowed determining those conditions that lead to a better assembly between the part and the metallic insert and to its structural integrity. The mechanical performance evaluation demonstrated that the part meets all its functional and structural requirements, validating simulation predictions.

Preparation of hybrid poly(lactic acid)/flax composites by the insert overmolding process: Evaluation of mechanical performance and thermomechanical properties

AbstractThis article presents research into the development of a new type of composite materials prepared with the use of the overmolding method. The overmolded insert for the tested samples was in the form of composite prepreg. Poly(lactic acid) (PLA)/flax laminate was prepared by the compression molding technique from the commingled fabric. Two types of materials were used during the injection molding stage: pure PLA and PLA/harl composite prepared with 20 wt% of the flax harl particles. Harl straw is a waste byproduct of the flax fiber manufacturing process. All samples were subjected to a detailed analysis of their mechanical properties, dynamic thermomechanical analysis (DMTA), and structure observations. The reinforcing efficiency of the used prepreg overmolding procedure was found to be very high. In addition to the significant increase in sample modulus, the most favorable improvement relates to impact test results. Most of the conducted studies confirm that high adhesion occurs between the composite insert and the injection‐molded material, which confirms the effectiveness of the used methodology.

Adaptive data-driven collaborative optimization of both geometric and loaded contact mechanical performances of non-orthogonal duplex helical face-milling spiral bevel and hypoid gears

Considering the duplex helical face-milling characteristics, an innovative adaptive data-driven collaborative optimization of both tooth flank geometric accuracy and loaded contact mechanical performance evaluations is developed for non-orthogonal spiral bevel and hypoid gears. Firstly, an advanced duplex helical face-milling is simulated for tooth flank modeling and an improved tooth contact analysis (TCA) is proposed for the sensitive assembly problem. Numerical loaded tooth contact analysis (NLTCA) is used to determine data-driven relations between the loaded contact mechanical performance evaluations and assembly error. Then, a new adaptive data-driven collaborative optimization model is established by modifying assembly error evaluations. In addition to tooth flank geometric accuracy, the loaded contact mechanical evaluations including loaded contact pattern, loaded transmission error, loaded contact pressure and loaded contact stress are used as main targets. Here, to get high accuracy and efficiency, the decision-making of collaborative optimization is divided into two sub-systems: i) Loaded contact mechanical performance multi-objective optimization (MOO) for target flank determination. Here, an achievement function approach is used to get Pareto optimal solution. ii) Tooth flank geometry optimization by assembly error modification. Where, sensitivity analysis strategy is applied to select the optimal design variables. The given numerical instance can verify the proposed method.

멤브레인 형 2차 방벽 이방성 복합재료의 섬유방향에 따른 기계적 성능 평가

멤브레인 형 2차 방벽 이방성 복합재료의 섬유방향에 따른 기계적 성능 평가

Molecular Mechanism and Extraction Performance Evaluation for Separation of Methanol and n-Hexane via Ionic Liquids as Extractant

Biodiesel is considered as one of the best resources to replace fossil fuels. There are a lot of mixtures of methanol and hexane in the process of biodiesel production. In this study, a green solve...

Experimental failure analysis and mechanical performance evaluation of fiber-metal sandwich laminates interleaved with polyamide-6,6 interlayers through the combined usage of acoustic emission, thermography and microscopy techniques

Fiber-metal laminates are hybrid sandwich composite structures made of thin metallic sheets and layers of fiber-reinforced plastics. In this study, for the first time, the effects of polyamide 66 nonwoven interlayers on the tensile, three-point bending, interlaminar shear strength, and low velocity impact responses of fiber-metal laminates are investigated by coupling acoustic emission, thermography, and microscopy techniques. The fiber-metal laminates are interleaved with polyamide 66 nonwoven fabrics at two different areal weight density, namely, 17 gsm (grams per square meter) and 50 gsm. The tensile, bending, interlaminar shear strength, and low velocity impact tests are carried out in accordance with the ASTM standards. During the tensile and flexural tests, acoustic emission data are collected to understand damage types occurring under various loading conditions and, in turn, clearly shed light on the performance of polyamide 66 for interfacial strengthening in fiber-metal laminates. The results of acoustic emission investigation are correlated with the optical and scanning electron microscope-based microscopic analysis. It is shown that the interlaminar shear strength of fiber-metal laminates can be increased significantly (about 42%) by using polyamide 66 nonwoven interlayers. The impacted fiber-metal laminate specimens are examined to determine damage area and length using the lock-in thermography method. It is found that the polyamide 66 interlayers decrease the debonded length and damaged area up to 39 and 32%, respectively. The tensile and flexural strength and modulus of the fiber-metal laminate are not significantly affected by the presence of polyamide 66 interlayers, except a negligible drop in the value of tensile and flexural strength by 6 and 4%, respectively. The polyamide 66 interlayers are proved to be very successful in enhancing plastic deformation ability of the matrix and bonding efficiency between aluminum and composite sections.

Prediction method of bridge static load test results based on Kriging model

To solve the problems of expensive bridge load test cost, traffic congestion influence, and damage to bridges by load test, the dynamic experimental results based on the inexpensive, safety inspection data and maintenance process of existing bridges are presented in this paper. The Kriging model is used for the intelligent analysis and prediction of the actual stiffnesses of the existing bridges as well as for the high-accuracy prediction of their static load experimental results. In order to achieve the above objectives, a sensitivity coefficient is selected based on the sensitivity analysis of the whole bridge, and the Kriging model is established and optimized to forecast and modify sensitive parameters for the high-precision correction of the model. Relative to other machine learning algorithm models, the Kriging model has higher parameter sensitivity and reliability. To verify the correctness and feasibility of the above mentioned methods, a continuous rigid frame bridge is selected as an engineering test object, and ANSYS, a finite element software, is used for modeling and analysis. The research results show that the finite element model modification method based on the Kriging process can employ inexpensive and convenient bridge dynamic load tests to modify the actual parameters of the finite element model in the Kriging process of bridges; consequently, the test results of static load experiments can be more accurately predicted. The correction results obtained by the Kriging model are in good agreement with test results and exhibit high precision and reliability; moreover, the method is less costly and good safety, and has minimal influence on traffic. Moreover, in view of the potential for conducting a large number of bridge mechanical performance evaluations on all levels and the effective simulation and performance prediction of existing bridge project maintenance decisions, the proposed method affords a new train of thought.