Determination of Rational Design and Geometric Parameters of a High-Performance Drill Based on a Mathematical Model of the Cutting Part

Processing of high-precision holes in one technological operation is an urgent problem of advanced manufacturing. Processing of precise holes in parts for aerospace and machine-building industries with a diameter of up to 30 mm is performed during countersinking, deployment or grinding operations. These operations are applied only if there already exists a pre-treated hole. Monolithic three-fluted drills have been becoming common for processing high-precision holes of 7-8 quality over the last few years. The processing of various types of materials such as stainless steels, cast iron and heat-resistant steels requires rational geometric and structural parameters of the cutting tool. The nature of the load distribution between all the teeth during drilling plays a huge role in the processing efficiency. Even load distribution between the three teeth and a positive geometry improves self-centering and reduces the deviation from the specified axis of the hole. The drill sharpening provides positive geometry along the entire main cutting edge. The influence of the geometric parameters of the cutting edge of the screw groove on the shape of the drill bit is equally important. Existing approaches to the design of the thinning do not account for the influence of the geometric parameters of the cutting edge on the section of the screw groove. Analytical approaches to modelling of the main cutting edges are typically married with difficulties associated with achieving a smooth change in the angle of inclination to the tangent of the cutting edge. The complexity of the aforementioned task is largely due to the presence of critical points at the interface of the spiral groove and thinning. Determining the rational shape of two sections of the main cutting edge performed in this study is a complicated task that includes several steps needed to find the number of nodal points. Achieving a positive rake angle in the normal section to the cutting edge at the gash area that was formed via a special sharpening is one of the most important results of this paper. The rational shape of the cutting edge and the front surface provides an increase in the strength of the cutting part by 1.3 times.

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Visual high-precision detection method for tool damage based on visual feature migration and cutting edge reconstruction

The International Journal of Advanced Manufacturing Technology ◽

10.1007/s00170-021-06919-5 ◽

2021 ◽

Author(s):

Zukun Ye ◽

Yulun Wu ◽

Guocai Ma ◽

Heng Li ◽

Zhijuan Cai ◽

...

Keyword(s):

High Precision ◽

Detection Method ◽

Cutting Edge ◽

Visual Feature ◽

Edge Reconstruction ◽

Tool Damage

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Design, Analysis and Test of a Hyperbolic Magnetic Field Voice Coil Actuator for Magnetic Levitation Fine Positioning Stage

Energies ◽

10.3390/en12101830 ◽

2019 ◽

Vol 12 (10) ◽

pp. 1830

Author(s):

Yiheng Zhou ◽

Baoquan Kou ◽

He Zhang ◽

Lu Zhang ◽

Likun Wang

Keyword(s):

Magnetic Field ◽

High Precision ◽

Magnetic Levitation ◽

Structural Parameters ◽

Industrial Applications ◽

Degree Of Freedom ◽

Force Density ◽

Precision Positioning ◽

Element Analysis ◽

Voice Coil Actuator

The multi-degree-of-freedom high-precision positioning system (MHPS) is one of the key technologies in many advanced industrial applications. In this paper, a novel hyperbolic magnetic field voice coil actuator using a rhombus magnet array (HMF-VCA) for MHPS is proposed. Benefiting from the especially designed rhombus magnet array, the proposed HMF-VCA has the advantage of excellent force uniformity, which makes it suitable for multi-degree-of-freedom high-precision positioning applications. First, the basic structure and operation principles of the HMF-VCA are presented. Second, the six-degree-of-freedom force and torque characteristic of the HMF-VCA is studied by three-dimensional finite element analysis (3-D FEA). Third, the influence of structural parameters on force density and force uniformity is investigated, which is conducive to the design and optimization of the HMF-VCA. Finally, a prototype is constructed, and the comparison between the HMF-VCA and conventional VCAs proves the advantage of the proposed topology.

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Live Load Distribution Factors for Skew Stringer Bridges with High-Performance-Steel Girders under Truck Loads

Applied Sciences ◽

10.3390/app8101717 ◽

2018 ◽

Vol 8 (10) ◽

pp. 1717 ◽

Cited By ~ 1

Author(s):

Iman Mohseni ◽

Yong Cho ◽

Junsuk Kang

Keyword(s):

Load Distribution ◽

Shear Force ◽

High Performance ◽

Structural Parameters ◽

Highway Bridges ◽

Live Load ◽

High Performance Steel ◽

Live Load Distribution Factors ◽

Live Load Distribution ◽

Load Distribution Factors

Because the methods used to compute the live load distribution for moment and shear force in modern highway bridges subjected to vehicle loading are generally constrained by their range of applicability, refined analysis methods are necessary when this range is exceeded or new materials are used. This study developed a simplified method to calculate the live load distribution factors for skewed composite slab-on-girder bridges with high-performance-steel (HPS) girders whose parameters exceed the range of applicability defined by the American Association of State Highway and Transportation Officials (AASHTO)’s Load and Resistance Factor Design (LRFD) specifications. Bridge databases containing information on actual bridges and prototype bridges constructed from three different types of steel and structural parameters that exceeded the range of applicability were developed and the bridge modeling verified using results reported for field tests of actual bridges. The resulting simplified equations for the live load distribution factors of shear force and bending moment were based on a rigorous statistical analysis of the data. The proposed equations provided comparable results to those obtained using finite element analysis, giving bridge engineers greater flexibility when designing bridges with structural parameters that are outside the range of applicability defined by AASHTO in terms of span length, skewness, and bridge width.

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The Super-Thin Rod Cylindrical Honing Technology Research

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.503-504.764 ◽

2012 ◽

Vol 503-504 ◽

pp. 764-767 ◽

Cited By ~ 1

Author(s):

Lin Zhu ◽

Lin Pan

Keyword(s):

Surface Roughness ◽

High Precision ◽

High Efficiency ◽

Slenderness Ratio ◽

Flexible Production ◽

Technology Research ◽

Processing Efficiency ◽

Stroke Length ◽

Roundness Error ◽

Cylindrical Grinding

The super-thin rod cylindrical grinding is a problem in the machining, super-thin rod with large slenderness ratio, poor rigidity, large roundness error after grinding, and with low processing efficiency. This study uses cylindrical honing processing super-thin rod parts, and designing the super-thin rod cylindrical honing head, carrying on a honing test. The results show that the super-thin rod cylindrical coarse honing capacity reach up to 0.002mm/double stroke(length 1698mm), surface roughness reach up to Ra 0.8 ~ 0.025μm after honing, roundness error reach up to 2μm. It fully shows that super-thin rod cylindrical honing technology has high precision, low surface roughness, flexible production processing and high efficiency.

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Lipophilicity and Click Reactivity Determine the Performance of Bioorthogonal Tetrazine Tools in Pretargeted in Vivo Chemistry

10.26434/chemrxiv.13482594 ◽

2020 ◽

Author(s):

Johanna Stéen ◽

Jesper Tranekjær Jørgensen ◽

Denk Christoph ◽

Umberto Maria Battisti ◽

Kamilla Nørregaard ◽

...

Keyword(s):

Targeted Delivery ◽

Rational Design ◽

Structural Parameters ◽

Early Time ◽

High Rate ◽

Drug Conjugates ◽

Compound Libraries ◽

Drug Concentrations ◽

The Impact

The development of highly selective and fast biocompatible reactions for ligation and cleavage has paved the way for new diagnostic and therapeutic applications of in vivo chemistry. The concept of bioorthogonal pretargeting has attracted considerable interest, in particular for the targeted delivery of radionuclides and drugs. In nuclear medicine, pretargeting can provide increased target-to-background ratios at early time-points compared to traditional approaches. This reduces the radiation burden to healthy tissue and, depending on the selected radionuclide, enables better imaging contrast or higher therapeutic efficiency. Moreover, bioorthogonally triggered cleavage of pretargeted antibody-drug conjugates represents an emerging strategy to achieve controlled release and locally increased drug concentrations. The toolbox of bioorthogonal reactions has significantly expanded in the past decade, with the tetrazine ligation being the fastest and one of the most versatile in vivo chemistries. Progress in the field, however, relies heavily on the development and evaluation of (radio)labeled compounds, preventing the use of compound libraries for systematic studies. The rational design of tetrazine probes and triggers has thus been impeded by the limited understanding of the impact of structural parameters on the in vivo ligation performance. In this work, we describe the development of a pretargeted blocking assay that allows for the investigation of the in vivo fate of a structurally diverse library of 45 unlabeled tetrazines and their capability to reach and react with pretargeted trans-cyclooctene (TCO)-tagged antibodies in tumor-bearing mice. This study enabled us to assess the correlation of click reactivity and lipophilicity of tetrazines with their in vivo performance. In particular, high rate constants (>50,000 M-1s-1) for the reaction with TCO and low calculated logD7.4 values (below -3) of the tetrazine were identified as strong indicators for successful pretargeted in vivo click chemistry. Click-radiolabeling gave access to a set of selected 18F-labeled tetrazines, including highly reactive scaffolds, which were used in pretargeted PET imaging studies to confirm the results from the blocking study. These insights thus enable the rational design of tetrazine probes for in vivo application and will thereby assist the clinical translation of bioorthogonal pretargeting.

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Analysis of load distribution and contact stiffness of the single-nut ball screw based on the whole rolling elements model

Transactions of the Canadian Society for Mechanical Engineering ◽

10.1139/tcsme-2018-0023 ◽

2019 ◽

Vol 43 (3) ◽

pp. 344-365 ◽

Cited By ~ 2

Author(s):

Ye Chen ◽

Chun-yu Zhao ◽

Si-yu Zhang ◽

Xian-li Meng

Keyword(s):

Load Distribution ◽

Contact Stiffness ◽

Structural Parameters ◽

Contact Angles ◽

Ball Screw ◽

Distribution Model ◽

Axial Stiffness ◽

Feed System ◽

Normal Contact ◽

Rolling Elements

This paper aims to investigate the load distribution and contact stiffness characteristics of the single-nut ball screw pair (SNBSP). First, the transformed relationship of coordinate systems is established. Then, the whole rolling elements load distribution model of the SNBSP is presented. Based on this, the whole rolling elements contact stiffness model is obtained. Applying the Newton–Raphson iterative method to solve the model, the normal force of rolling elements and the contact angles between balls and raceway surface are determined. The calculation results are reasonably consistent with those of the half pitch model. Then, the local contact stiffness and global contact stiffness are obtained. Furthermore, the effects of axial load and structural parameters of the SNBSP on the normal contact force, contact angle, and local and global contact stiffness are discussed using numeric analysis. Finally, a dynamic model of the z-axis feed system with time-varying axial stiffness is established, and the accuracy of the model is verified by experiments.

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Automation Tool Preparation in the Conditions of Production

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.770.739 ◽

2015 ◽

Vol 770 ◽

pp. 739-743 ◽

Cited By ~ 6

Author(s):

A.S. Yuanyushkin ◽

D.V. Lobanov ◽

D.A. Rychkov

Keyword(s):

Comparative Analysis ◽

Rational Design ◽

Economic Effect ◽

Optimal Choice ◽

Processing Efficiency ◽

Time Required ◽

The Given ◽

High Processing ◽

Selection Of

The key task of the tool manufacturing is to create or to choose such a type of tool, which would permit to provide high processing efficiency, the best tool`s workability and the quality of the machined surfaces with minimum expenses and resources. The optimal choice of the constructive tool modifications from a variety of options takes much time required for the preparation of the tool to work. To solve this problem, we have developed software that allows you to create, organize and carry out a comparative analysis of structural instruments in order to identify rational option for the given conditions of production. Ordering and selection of a rational design of the instrument is carried out in accordance with established procedures of modeling and comparative analysis of design solutions. Application software can reduce design time technological process by 80...90%, and get a substantial annual economic effect.

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MODELING OF HIGH PRECISION POSITIONING SYSTEM / DIDELIO TIKSLUMO PADĖTIES NUSTATYMO SISTEMOS MODELIAVIMAS

Mokslas - Lietuvos ateitis ◽

10.3846/mla.2013.104 ◽

2013 ◽

Vol 5 (6) ◽

pp. 633-637

Author(s):

Giedrius Augustinavičius ◽

Audrius Čereška

Keyword(s):

Mathematical Model ◽

High Precision ◽

Positioning System ◽

Reduction Mechanism ◽

Precision Positioning ◽

Analytical Approaches ◽

The Mathematical Model ◽

Architecture Optimization ◽

Fine Adjustment

This paper presents the modeling of a flexure-based precisionpositioning system for micro-positioning uses. The positioningsystem is featured with monolithic architecture, flexure-basedjoints and ultra fine adjustment screws. Its workspace has beenevaluated via analytical approaches. Reduction mechanism isoptimally designed. The mathematical model of the positioningsystem has been derived, which is verified by resorting to finiteelement analysis (FEA). The established analytical and (FEA)models are helpful for a reliable architecture optimization andperformance improvement of the positioning system. Santrauka Straipsnyje pristatomas didelio tikslumo centravimo ir niveliavimo padėties nustatymo sistemos su besideformuojančiais mechanizmais kūrimas ir modeliavimas. Padėties nustatymo sistema optimizuota Solidworks Simulation programiniu paketu. Centravimo platformų poslinkiams apskaičiuoti sudarytas matematinis modelis, kurio patikimumas buvo patikrintas taikant baigtinių elementų metodą. Sudaryto matematinio modelio ir rezultatų, gautų pritaikius baigtinių elementų metodą, skirtumai buvo mažesni nei 10 %. Pasiūlyta modeliavimo metodika gali būti taikoma kuriant padėties nustatymo sistemas su besideformuojančiais mechanizmais.

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