This paper presents a novel two-dimensional vibration-assisted compliant cutting system (2-D VCCS) to be used on conventional machines for generating textured surfaces with uniform and accurate topography. The proposed is specifically designed capable of delivering high-amplitude vibrations decoupled guidance at the tool tip, while keeping high resistance forces during texturing process. matrix-based compliance modeling method adopted dynamic 2-D VCCS. With optimized structural parameters,...

This research study focuses on the experimental analysis of three-dimensional (3D) surface topography and roughness workpiece machined with ultrasonic vibration assisted turning (UAT) in comparison to conventional (CT). For challenge that machining difficulties 304 austenitic stainless steel (ASS 304) high demands for quality precision represent, starting cutting principle processing technology, method is employed scheme out a system (MS-UAT). The experiments ASS are conducted without using...

We examined the role of ventromedial prefrontal cortex (VMPFC) in memory retrieval monitoring. Event-related potentials were recorded while patients with VMPFC lesions and matched controls viewed faces personal acquaintances, famous nonfamous people, indicated whether they had personally encountered these individuals. Patients more likely than to make both false positive negative errors. Both groups showed a large posterior wave peaking at approximately 170 ms after face onset (N170). In...

The discrimination of concurrent sounds is paramount to speech perception. During social gatherings, listeners must extract information from a composite acoustic wave, which sums multiple individual voices that are simultaneously active. observers' ability identify two presented vowels improves with increasing separation between the fundamental frequencies (f0) vowels. Event-related potentials stimuli during attend and ignore conditions revealed activity 130 170 msec after sound onset...

The aim of this paper is to present an experimental investigation the cutting forces, surface quality, tool wear and chip shape in ultrasonic vibration assisted turning (UAT) 304 austenitic stainless steel (ASS 304) comparison conventional (CT). This study focuses on solution machining difficulties ASS high demands for processing quality efficiency. system UAT schemed out assure desired effect by utilizing method. Meanwhile, a series systematic experiments are performed with without using...

With excellent properties, high-temperature superalloys have become the main application materials for aircraft engines, gas turbines, and many other devices. However, are typically difficult to machine, especially thread cutting. In this article, an ultrasonic vibration–assisted turning system is proposed cutting operations in superalloys. A theoretical analysis of carried out. An was integrated into a standard lathe demonstrate Inconel 718 superalloy. The influence machining on workpiece...

Alumina (Al2O3) is an extremely hard and brittle ceramic that usually used as abrasive or a cutting tool insert in manufacturing. However, its growing applications industrial products make it necessary to conduct study of the machinability alumina themselves with cost-effective flexible method, rather than conventional diamond grinding laser-assisted processing methods. In this paper, polycrystalline tools are investigate machining nonporous pure by applying inclined ultrasonic elliptical...

Most of the acoustic cloak designs are based on stationary medium, which, however, may be inaccurate in many practical applications with non-uniform flows. The optimization cloaking performance was described as an active noise control problem, and theoretical model by Huang, Zhong, Stalnov [J. Acoust. Soc. Am. 135(5), 2571-2580 (2014b)] employed for quick evaluation sound scattering. In this work, extensions made to address unsolved but essential issues model. First, impact discontinuities...

Previous studies on autoignition propagation modes were often performed based constant-volume configuration. However, the reactant mixture in reciprocating engines always experiences significant variable volume and ever-changing thermodynamic conditions, which may affect initiation subsequent development during knocking combustion. In this study, reaction wave induced by thermal stratifications was investigated numerically, with addressing role of piston motion primary flame compression....

Auto-ignition phenomena are paid more attention due to their close relation with abnormal combustions in advanced internal combustion engines. Previous investigations on intensive auto-ignition and knocking have been mainly conducted under standard flow conditions, whereas the role of turbulence is not fully clarified engine-relevant conditions. In this study, forced affected modes were investigated a novel rapid compression facility fueled isooctane/air mixtures. combination instantaneous...

Ultrasonic vibration cutting can be widely used in lathe, planer, milling machine, grinding thread processing and gear processing, etc. system is composed mainly of ultrasonic generator, transducer, luffing rod, tool, Here, generator the most important. The stand or fall signal, which produced by has direct influence on anticipated effect ability machining. In order to generate a suitable for machining, studied, signal based digital frequency synthesis (DDS) designed conducted test with this...

A novel ultrasonic vibration‐assisted structure for radial milling is proposed, and the (UVARM) further studied in terms of theoretical model experiment. The motion feed characteristics UVARM are also analyzed. special fixture designed to construct experimental platform UVARM, which vibration applied workpiece along direction. preliminary results show that with increase spindle speed, force both conventional cutting (CC) experiments tends increase. In addition, when per tooth increased,...

Balconies can provide noise shielding for residents who live in high-rise apartment buildings. The efficiency of reduction induced by a balcony largely depends on the shape ceiling. This study aims to optimize ceiling two-dimensional simplified urban building enhance mitigation using level-set based topology optimization, which is capable providing distinct and smooth interface. Noise sources at both single multi-frequency optimization are considered. In single-frequency two peak frequencies...

This study examined whether 1-hour perceptual training could elicit feature-specific improvement of performance and corresponding cortical plasticity in humans during speech segregation by using magnetoencephalography (MEG). One group participants learned to segregate concurrent vowels difference fundamental frequency (f0) while the other use sound location. MEG recordings were conducted after required identify two different vowels, which may have same f0 location or differ only, only both...