Traditional regenerative stability theory predicts a set of optimally stable spindle speeds at integer fractions the natural frequency most flexible mode system. The assumptions this become invalid for highly interrupted machining, where ratio time spent cutting to not (denoted ρ) is small. This paper proposes new machining that doubling in number as value ρ becomes results are supported by numerical simulation and experiment. It anticipated will be relevant choosing optimal parameters...

We present an optically-detected mechanical accelerometer that achieves a sensitivity of 100 ng/rtHz over bandwidth 10kHz and is traceable. have incorporated Fabry-Perot fiber-optic micro-cavity currently capable measuring the test-mass displacement with sensitivities 200 am/rtHz, whose length determination enables traceability to International System Units (SI). The compact size high mQ-product achieved combined simplicity implemented optical detection scheme highlight our device this...

To have confidence in force measurements made with atomic microscopes (AFMs), the spring constant of AFM cantilevers should be known good precision and accuracy, a topic not yet thoroughly treated literature. In this study, we compared stiffnesses uncoated tipless uniform rectangular silicon among thermal, loading, geometric calibration methods; loading was done against an artifact from National Institute Standards Technology (NIST). The calibrated at NIST using forces that were traceable to...

Quantifying uncertainty in measured properties of nanomaterials is a prerequisite for the manufacture reliable nanoengineered materials and products. Yet, rigorous quantification (UQ) rarely applied material property measurements with atomic force microscope (AFM), widely used instrument that can measure at nanometer scale resolution both inorganic biological surfaces nanomaterials. We present framework to ascribe local nanomechanical any nanoparticle or surface AFM by taking into account...

For the past two years, measurements have been performed with a watt balance at National Institute of Standards and Technology (NIST) to determine Planck constant.A detailed analysis these their uncertainties has led value h = 6.626 069 79(30) × 10 -34 J s.The relative standard uncertainty is 45 -9 .This result 141 fractionally higher than h90.Here h90 conventional constant given by ≡ 4/(K 2 J-90 RK-90), where KJ-90 RK-90 denote values Josephson von Klitzing constants, respectively.

A precise instrument, called a watt balance, compares mechanical power measured in terms of the meter, second, and kilogram to electrical volt ohm. direct link between action Planck constant is established by practical realization units derived from Josephson quantum Hall effects. We describe this paper fourth-generation balance at National Institute Standards Technology (NIST), report our initial determination obtained data taken late 2015 beginning 2016. comprehensive analysis associated...

Although mass is typically defined within the International System of Units (SI) at kilogram level, pending SI redefinition provides an opportunity to realize any scale using electrical metrology.We propose use electromechanical balance milligram level units.An integrated concentric-cylinder vacuum gap capacitor allows us leverage highly precise references available for capacitance, voltage and length generate electrostatic reference force.Weighing experiments performed on 1 mg 20 artifacts...

The role of perturbation methods and bifurcation theory in predicting the stability complicated dynamics machining is discussed using a nonlinear single-degree-of-freedom model that accounts for regenerative effect, linear structural damping, quadratic cubic stiffness machine tool, linear, quadratic, terms. Using width cut w as parameter, we find, theory, disturbances decay with time hence chatter does not occur if < wc grow exponentially occurs > wc. In other words, increases past wc,...

This paper reviews the current status of small force metrology for quantitative instrumented indentation and atomic microscopy (AFM), in particular focuses on new electrical deadweight standards developed at National Institute Standards Technology (NIST). These provide metrological infrastructure so that users AFM can achieve nanomechanical testing materials, engineered surfaces micro nanoscale devices terms forces are expressed internationally accepted units measure with quantified uncertainty.

We have developed a fiber-optic interferometer optimized for best performance in the frequency range from dc to 1 kHz, with displacement linearity of 1% over +/- 25 nm, and noise-limited resolution 2 pm. The uses tunable infrared laser source (nominal 1550 nm wavelength) high amplitude wavelength stability, low spontaneous self-emission noise, sideband suppression, coherence control feature that broadens linewidth dramatically lowers low-frequency noise system. stability source, combined use...

Measurements of forces less than a micronewton are critical when examining the mechanical behaviour materials and devices at characteristic length scales below micrometre. As result, specification standards for nanomechanical tests test equipment being proposed by international organizations, an infrastructure traceable small force calibration is developing. In this context, results reported from first interlaboratory comparison micronewton-level metrology. The basis was set five...

We present an optomechanical accelerometer with high dynamic range, bandwidth and read-out noise levels below 8 ${\mu}$g/$\sqrt{\mathrm{Hz}}$. The straightforward assembly low cost of our device make it a prime candidate for on-site reference calibrations autonomous navigation. experimental data taken vacuum sealed, portable prototype deduce the achieved bias stability scale factor accuracy. Additionally, we comprehensive model physics that use to analyze fundamental sources accuracy...

A theoretical and experimental investigation into the stability of a slender boring bar under regenerative cutting conditions is presented. The has been equipped with actuators sensors for feedback control its structural dynamics. It modelled at tool point by mass–spring–damper system free to move in two mutually perpendicular directions. Our aim demonstrate effect simple on parameter space chatter–free machining process using theory experiment. We reinforce notion that design should provide...

A series of extremely uniform prototype reference cantilevers has been created that can be used to calibrate the spring constants atomic force microscopy (AFM) and other micromechanical structures. By utilizing optimal combinations material, design latest microfabrication processing techniques, arrays were from single crystal (1 0 0) silicon. Nominal estimated in range 0.02 N m−1 0.2 m−1. Resonance frequency measurements assess uniformity devices different portions a silicon-on-insulator...

We describe a method to calibrate the spring constants of cantilevers for atomic force microscopy (AFM). The makes use "piezosensor" composed piezoresistive cantilever and accompanying electronics. piezosensor was calibrated before with an absolute standard, NIST electrostatic balance (EFB). In this way, acts as transfer standard traceable International System Units. Seven single-crystal silicon rectangular geometries nominal from 0.2 40 Nm were measured method. values obtained constant...

Researchers at the National Institute of Standards and Technology(NIST) have measured value Planck constant to be $h =6.626\,069\,934(89)\times 10^{-34}\,$J$\,$s (relative standard uncertainty $13\times 10^{-9}$). The result is based on over 10$\,$000 weighings masses with nominal values ranging from 0.5$\,$kg 2$\,$kg Kibble balance NIST-4. has been reduced by more than twofold relative a previous determination because three factors: (1) much larger data set previously available, allowing...

Researchers at the National Institute of Standards and Technology have been using a watt balance, NIST-3, to measure Planck constant h for over ten years. Two recently published values disagree by more than one standard uncertainty. The motivation present short communication is twofold. First, we correct latest number take into account discovered systematic error in mass dissemination Bureau International des Poids et Mesures. Second, provide guidance on how combine two numbers final result....

Experiments show that the torsion modes of nanostructures can experience dissipation dilution, yielding a new class ultrahigh-Q resonators with broad applications to quantum experiments and precision measurement.

The National Institute of Standards and Technology (NIST) has launched a five-year Microforce Realization Measurement Project focusing on the development an instrument laboratory capable realizing measuring SI unit force below 5/spl times/10/sup -6/ N using electrical units as link to International System Units (SI). As proof principle, prototype electromechanical balance been developed allow comparisons between mechanically electrically derived forces up 300 /spl mu/N with resolution 15 nN....