9 research outputs found
On the Nonlinear Tribological Jerk Dynamics at Sliding Interfaces
No full textAs the world desires the next industrial revolution, the potential threats that will undermine energy efficient innovations include detrimental frictional effects that exacerbate wear, hasten equipment breakdowns, and worsen heat dissipation. Capturing the inherently nonlinear manifestations of friction fundamentally has been difficult. A fundamental modeling scheme elucidating friction will bolster novel technologies synthesizing wear resistant materials and lubricants needed for sustainable energy efficiency. Frictional dissipation at dynamical sliding interfaces has been studied for generations. Interfacial sliding frictional effects are prevalent in natural and artificial phenomena such as earthquake, hip and knee joints, and the moving parts of energy-producing and energy-consuming equipment. Hitherto, despite significant research efforts, no consensus fundamental modeling technique exists that deterministically ties friction with system degradation. Yet, elucidating the basic physics of nonlinear friction-resisted motion will clarify how heat generation, efficiency, lubrication, wear, and material lifetime evolve in sliding contacts. In this study, we unify Newtonian mechanics with classical thermodynamics to elicit nonlinear tribological jerk dynamics at a sliding interface. Jerk, the rate of change of acceleration has been elusive in classical mechanics. By showing jerk originating in a friction-resisted motion a new fundamental scientific modeling tool emerges. For example, although Coulomb's law of friction precludes significant friction-velocity coupling our reassessment using jerk dynamics results shows otherwise. We find Coulomb's law may seemingly be an oversimplification by reproducing the Stribeck effect known to capture friction-velocity coupling. Furthermore, negative frictional jerk opposes relative motion while positive lubricating jerk supports relative motion. A frictionless unconstrained motion recaptures constant acceleration Newtonian-Galilean mechanics. Using the kinematic and dynamic results as inputs, we quantified wear and wear rates, subsurface temperature and mechanical sliding efficiency. Our modeling results quantitatively match experimental results from tribometer and thermal compliance tests very well. We constructed an analytical algebraic partitioning technique to solve the jerk balance equations which are third order and nonlinear ordinary differential equations. The algebraic technique works well and may facilitate engineering and scientific modeling efforts. By placing jerk in basic physics context, we proffer a fundamental tool that likely will transform how relative motions in artificial and natural phenomena are modeled.2017-06-0
On the Nonlinear Tribological Jerk Dynamics at Sliding Interfaces
No full textAs the world desires the next industrial revolution, the potential threats that will undermine energy efficient innovations include detrimental frictional effects that exacerbate wear, hasten equipment breakdowns, and worsen heat dissipation. Capturing the inherently nonlinear manifestations of friction fundamentally has been difficult. A fundamental modeling scheme elucidating friction will bolster novel technologies synthesizing wear resistant materials and lubricants needed for sustainable energy efficiency.
Frictional dissipation at dynamical sliding interfaces has been studied for generations. Interfacial sliding frictional effects are prevalent in natural and artificial phenomena such as earthquake, hip and knee joints, and the moving parts of energy-producing and energy-consuming equipment. Hitherto, despite significant research efforts, no consensus fundamental modeling technique exists that deterministically ties friction with system degradation. Yet, elucidating the basic physics of nonlinear friction-resisted motion will clarify how heat generation, efficiency, lubrication, wear, and material lifetime evolve in sliding contacts.
In this study, we unify Newtonian mechanics with classical thermodynamics to elicit nonlinear tribological jerk dynamics at a sliding interface. Jerk, the rate of change of acceleration has been elusive in classical mechanics. By showing jerk originating in a friction-resisted motion a new fundamental scientific modeling tool emerges. For example, although Coulomb\u27s law of friction precludes significant friction-velocity coupling our reassessment using jerk dynamics results shows otherwise. We find Coulomb\u27s law may seemingly be an oversimplification by reproducing the Stribeck effect known to capture friction-velocity coupling. Furthermore, negative frictional jerk opposes relative motion while positive lubricating jerk supports relative motion. A frictionless unconstrained motion recaptures constant acceleration Newtonian-Galilean mechanics. Using the kinematic and dynamic results as inputs, we quantified wear and wear rates, subsurface temperature and mechanical sliding efficiency. Our modeling results quantitatively match experimental results from tribometer and thermal compliance tests very well.
We constructed an analytical algebraic partitioning technique to solve the jerk balance equations which are third order and nonlinear ordinary differential equations. The algebraic technique works well and may facilitate engineering and scientific modeling efforts.
By placing jerk in basic physics context, we proffer a fundamental tool that likely will transform how relative motions in artificial and natural phenomena are modeled
A study of digital platform for physical product development
No full textThe world is currently in the middle of a digital revolution where digital platforms have become an important part of industrial engineering, management solutions and economic values. There is huge potential for digital platforms to contribute to various manufacturing processes such as physical product development. In this study we will be discussing the various stakeholders collaborating in the new product development process, their challenges and how digital platforms can ease those challenges. The aim of the study is to identify the challenges faced by the various stakeholders collaborating and engaging in various product development processes from product idea to mass production, and then suggest possible digital solutions to deal with those challenges. The theory used to discuss the results is the collaboration theory, “Five stage model of collaboration”. The study followed a qualitative study approach using semi-structured interview to gather data and thematic analysis for data analysis. Four stakeholders were identified, namely, idea owners, incubators, manufacturers, and financers. At least one participant from each category was interviewed and the data collected was coded into first order concepts, second order concepts and finally into themes. The challenges that were identified from data analysis were interaction problems, engagement challenges, time and work effectiveness problems, proficiency challenge, agreement challenges and endorsement problems and the theme communication was the major and most common challenge identified amongst the stakeholders. The digital solutions AI auto match technology, multi-flow communication channel, safe and encrypted file sharing and tracing of activities, planning, and monitoring progress, learning and equipment with a detailed product development guide, and collaboration on multiple projects through a digital platform have been suggested to overcome these challenges. The importance of stakeholder engagement on digital platforms and the role of digital platforms to provide an engaging and user-friendly experience have been discussed as well. We believe that digital platforms through digital solutions may encourage innovation and sustainable development in the future
Study the effect of nitrogen flow rate on tribological properties of tantalum nitride based coatings
No full textEffect of sputtering pressure on molybdenum oxide thin films prepared by RF magnetron sputtering
No full text
A study of correlation between posterior palatal seal width and soft palatal angulation with palatal contour
No full textContext: The spatial relationship of posterior palatal seal (PPS) width and vibrating lines varies among individuals. Such variability could be related to contour of the palate.
Aims: The study was carried out to evaluate the relationship between PPS width of the patient intra-orally and cephalometric tracing of the same patient. Second part of the study was formulated to determine whether the anterior and posterior vibrating lines can be distinguished as two separate lines by different observers.
Materials and Methods: A lateral cephalogram was made to trace the hard and soft palatal contour, and the angle of the palatal contour was measured with the v-ceph program. Correlation analysis was conducted to examine the relationship between the distance from anterior to posterior vibrating lines and the angle of the palatal contour at the junction of the hard and soft palate.
Statistical Analysis Used: The data were analyzed using the Karl Pearson Correlation test.
Results: Correlation of the angle of the palatal contour to PPS width, showed perfectly positive value; whereas, correlation of angle between anterior nasal spine-posterior nasal spine (ANS-PNS) and PNS-Uvula (U) to PPS width showed partially positive value.
Conclusion: The correlation of angle between hard tissue and soft tissue to PPS width, and the angle between ANS-PNS and PNS-U to PPS width, increases with an increase in PPS width
