An Investigation of the Vibration Testing Method for Small Diameter Endmills

2014 ◽  
Vol 625 ◽  
pp. 134-139
Author(s):  
Takenori Ono
Keyword(s):  
Small Diameter ◽  
Milling Process ◽  
Modal Parameters ◽  
Vibration Testing ◽  
Function Generator ◽  
Testing Method ◽  
Milling Tool ◽  
Compliance Curve ◽  
Vibration Tests ◽  
The Impact

This paper introduced about the in-process vibration testing method for small diameter endmill. By this method, the natural frequency and modal parameters such as mass, damping, and stiffness of the milling tool can be determined in the milling process. An oscillation of the vibrator is controlled by the function generator to apply the impact force at the appropriate cutting period. The measurement setup can determine the compliance curve by the measurement signals of the exiting force and tool deformation. To evaluate the feasibility of the new method, vibration tests were performed on a square endmill which has the diameter of 4 mm in the milling on brass material. Results of vibration tests show that modal parameters of the specific vibration mode can be determined by the new developed method.

Research on Tool Wear Form in Micro Turn-Milling Process

2012 ◽  
Vol 184-185 ◽  
pp. 663-667 ◽  
Author(s):  
Lin Hui Zhao ◽  
Jian Cheng Zhang ◽  
Wei Su
Keyword(s):  
Tool Wear ◽  
Small Diameter ◽  
Milling Process ◽  
Milling Tool ◽  
Key Factor ◽  
Part Surface ◽  
End Mills ◽  
Series Of Experiments ◽  
Turn Milling ◽  
Wear Condition

In micro machining, turn-milling tool wear is a key factor for part surface quality. This paper carries on experiments on end mills wear in micro turn-milling machining, aiming to research the wear form and provide some reference data for developing wear standard of small diameter end mills. To measure wear condition of end mills, machine vision technique is utilized. This paper designs and sets up an online end mill wear measurement system for a micro turn-milling process center. With a series of experiments on small diameter end mills, wear conditions of different cutting positions are researched. Based on analysis of experiment data, wear characteristics and wear rule for micro turn-milling process are summarized in this paper.

Vibration Testing as a Tool to Optimize the Configuration of the PCBs

2014 ◽  
Vol 2014 (1) ◽  
pp. 000050-000054
Author(s):  
I. Szendiuch ◽  
B. Psota ◽  
A. Otáhal ◽  
M. Klapka
Keyword(s):  
Mechanical Stress ◽  
Design Process ◽  
High Density ◽  
Harsh Environment ◽  
Vibration Testing ◽  
Stress Optimization ◽  
New Construction ◽  
Vibration Tests ◽  
Eu Project ◽  
The Impact

This paper is linked to the EU project Euripides Eureka BOB (Board on Board) which is a joint solution for companies from four European countries. Its goal is the development, design, implementation and validation of an innovative configuration of the PCBs in 2.5D arrangement, which is designed for applications with a high density of components, and must meet the requirements for reliability in harsh environment and the ability to repair. To minimize the effect of mechanical stress is one of the priorities of this new construction, where a high density of components occurs on both sides of the PCB configuration. Therefore, any new solution, especially in 2.5D configuration, designed for harsh environment, requires mechanical stress optimization, already in the board's design process. Shock and vibration tests are also essential steps to reliability and quality assurance. This paper suggests as a simple example of one possible way to achieve this goal using vibration testing, including vibration simulations in ANSYS, to optimize the layout during the PCB design process. The optimization process consists of a sequence of necessary steps that need to be performed. The main contribution of this work is to show the first approach in the simulation of vibrations, and demonstrate that this path can help you choose the best design and layout of PCB, so as to avoid later problems caused by mechanical influences. In summary, specific rules are provided for verification of mechanical reliability by vibration testing and the most important properties of PCBs are defined. This procedure is in general suitable for use primarily in the design of any PCB, where you can prevent possible complications due to the impact of mechanical stress on the reliability of newly developed products.

scholarly journals Coir Fibers Treated with Henna as a Potential Reinforcing Filler in the Synthesis of Polyurethane Composites

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1128
Author(s):  
Sylwia Członka ◽  
Anna Strąkowska ◽  
Agnė Kairytė
Keyword(s):  
Mechanical Properties ◽  
High Energy ◽  
Dynamic Mechanical Properties ◽  
Milling Process ◽  
Coir Fiber ◽  
Lawsonia Inermis ◽  
Coir Fibers ◽  
Mechanical Performances ◽  
The Impact ◽  
Reinforcing Filler

In this study, coir fibers were successfully modified with henna (derived from the Lawsonia inermis plant) using a high-energy ball-milling process. In the next step, such developed filler was used as a reinforcing filler in the production of rigid polyurethane (PUR) foams. The impact of 1, 2, and 5 wt % of coir-fiber filler on structural and physico-mechanical properties was evaluated. Among all modified series of PUR composites, the greatest improvement in physico-mechanical performances was observed for PUR composites reinforced with 1 wt % of the coir-fiber filler. For example, on the addition of 1 wt % of coir-fiber filler, the compression strength was improved by 23%, while the flexural strength increased by 9%. Similar dependence was observed in the case of dynamic-mechanical properties—on the addition of 1 wt % of the filler, the value of glass transition temperature increased from 149 °C to 178 °C, while the value of storage modulus increased by ~80%. It was found that PUR composites reinforced with coir-fiber filler were characterized by better mechanical performances after the UV-aging.

scholarly journals Optimization and Tuning of Passive Tuned Mass Damper Embedded in Milling Tool for Chatter Mitigation

2020 ◽  
Vol 5 (1) ◽  
pp. 2
Author(s):  
Wenshuo Ma ◽  
Jingjun Yu ◽  
Yiqing Yang ◽  
Yunfei Wang
Keyword(s):  
Tuned Mass Damper ◽  
Structural Features ◽  
Milling Process ◽  
Diameter Ratio ◽  
Depth Of Cut ◽  
Receptance Coupling ◽  
Milling Tool ◽  
Mass Damper ◽  
Large Length ◽  
Deep Depth

Milling tools with a large length–diameter ratio are widely applied in machining structural features with deep depth. However, their high dynamic flexibility gives rise to chatter vibrations, which results in poor surface finish, reduced productivity, and even tool damage. With a passive tuned mass damper (TMD) embedded inside the arbor, a large length–diameter ratio milling tool with chatter-resistance ability was developed. By modeling the milling tool as a continuous beam, the tool-tip frequency response function (FRF) of the milling tool with TMD was derived using receptance coupling substructure analysis (RCSA), and the gyroscopic effect of the rotating tool was incorporated. The TMD parameters were optimized numerically with the consideration of mounting position based on the maximum cutting stability criterion, followed by the simulation of the effectiveness of the optimized and detuned TMD. With the tool-tip FRF obtained, the chatter stability of the milling process was predicted. Tap tests showed that the TMD was able to increase the minimum real part of the FRF by 79.3%. The stability lobe diagram (SLD) was predicted, and the minimum critical depth of cut in milling operations was enhanced from 0.10 to 0.46 mm.

scholarly journals Elastic Modulus and Elasticity Ratio of Malignant Breast Lesions with Shear Wave Ultrasound Elastography: Variations with Different Region of Interest and Lesion Size

Diagnostics ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1015
Author(s):  
Antonio Bulum ◽  
Gordana Ivanac ◽  
Eugen Divjak ◽  
Iva Biondić Špoljar ◽  
Martina Džoić Dominković ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Shear Wave ◽  
Large Diameter ◽  
Small Diameter ◽  
Shear Wave Elastography ◽  
Lesion Size ◽  
Ultrasound Elastography ◽  
Breast Lesions ◽  
Malignant Breast ◽  
The Impact

Shear wave elastography (SWE) is a type of ultrasound elastography with which the elastic properties of breast tissues can be quantitatively assessed. The purpose of this study was to determine the impact of different regions of interest (ROI) and lesion size on the performance of SWE in differentiating malignant breast lesions. The study included 150 female patients with histopathologically confirmed malignant breast lesions. Minimal (Emin), mean (Emean), maximal (Emax) elastic modulus and elasticity ratio (e-ratio) values were measured using a circular ROI size of 2, 4 and 6 mm diameters and the lesions were divided into large (diameter ≥ 15 mm) and small (diameter < 15 mm). Highest Emin, Emean and e-ratio values and lowest variability were observed when using the 2 mm ROI. Emax values did not differ between different ROI sizes. Larger lesions had significantly higher Emean and Emax values, but there was no difference in e-ratio values between lesions of different sizes. In conclusion, when measuring the Emin, Emean and e-ratio of malignant breast lesions using SWE the smallest possible ROI size should be used regardless of lesion size. ROI size has no impact on Emax values while lesion size has no impact on e-ratio values.

The Impact of Ball Milling Process Parameters on the Preparation of Nano Silicon Powder

2021 ◽  
Vol 217 (1) ◽  
pp. 255-264
Author(s):  
Xiaomeng Zhu ◽  
Xiaolan Cai ◽  
Shuang Zhang ◽  
Lei Wang ◽  
Xudong Cui
Keyword(s):  
Ball Milling ◽  
Process Parameters ◽  
Silicon Powder ◽  
Milling Process ◽  
Ball Milling Process ◽  
Nano Silicon ◽  
The Impact

scholarly journals The Impact of Changing to an Algorithm-Based Clostridioides difficile Test on the Decision to Treat Clostridioides difficile

2020 ◽  
Vol 41 (S1) ◽  
pp. s407-s407
Author(s):  
Lana Dbeibo ◽  
Joy Williams ◽  
Josh Sadowski ◽  
William Fadel ◽  
Vera Winn ◽  
...  
Keyword(s):  
Critical Care ◽  
Toxic Megacolon ◽  
Adverse Outcomes ◽  
Clinical Criteria ◽  
Testing Method ◽  
Clostridioides Difficile ◽  
Critical Care Admission ◽  
The Impact ◽  
Test Result ◽  
Pcr Test

Background: Polymerase chain reaction (PCR) testing for the diagnosis of Clostridioides difficile infection (CDI) detects the presence of the organism; a positive result therefore cannot differentiate between colonization and the pathogenic presence of the bacterium. This may result in overdiagnosis, overtreatment, and risking disruption of microbial flora, which may perpetuate the CDI cycle. Algorithm-based testing offers an advantage over PCR testing as it detects toxin, which allows differentiation between colonization and infection. Although previous studies have demonstrated the clinical utility of this testing algorithm in differentiating infection from colonization, it is unknown whether the test changes CDI treatment decisions. Our facility switched from PCR to an algorithm-based testing method for CDI in June 2018. Objective: In this study, we evaluated whether clinicians’ decisions to treat patients are impacted by a test result that implies colonization (GDH+/Tox−/PCR+ test), and we examined the impact of this decision on patient outcomes. Methods: This is a retrospective cohort study of inpatients with a positive C. diff test between June 2017 and June 2019. The primary outcome was the proportion of patients treated for CDI. We compared this outcome in 3 groups of patients: those with a positive PCR test (June 2017–June 2018), those who had a GDH+/Tox−/PCR+ or a GDH+/Tox+ test result (June 2018–June 2019). Secondary outcomes included toxic megacolon, critical care admission, and mortality in patients with GDH+/Tox−/PCR+ who were treated versus those who were untreated. Results: Of patients with a positive PCR test, 86% were treated with CDI-specific antibiotics, whereas 70.4% with GDH+/Tox+ and 29.25% with GDH+/Tox−/PCR+ result were treated (P < .0001). Mortality was not different between patients with GDH+/Tox−/PCR+ who were treated versus those who were untreated (2.7% vs 3.4%; P = .12), neither was critical care admission within 2 or 7 days of test result (2% vs 1.4%; P = .15) and (4.1% vs 5.4%, P = .39), respectively. There were no cases of toxic megacolon during the study period. Conclusions: The change to an algorithm-based C. difficile testing method had a significant impact on the clinicians’ decisions to treat patients with a positive test, as most patients with a GDH+/Tox−/PCR+ result did not receive treatment. These patients did not suffer more adverse outcomes compared to those who were treated, which has implications for testing practices. It remains to be explored whether clinicians are using clinical criteria to decide whether or not to treat patients with a positive algorithm-based test, as opposed to the more reflexive treatment of patients with a positive PCR test.Funding: NoneDisclosures: None

scholarly journals Analysing Random Vibration of KLT Box during Transporting by Finite Element Method

10.29007/b1th ◽  
2022 ◽  
Author(s):  
Cong Hoa Vu ◽  
Ngoc Thien Ban Dang
Keyword(s):  
Finite Element ◽  
Spectral Density ◽  
Power Spectral Density ◽  
Automotive Industry ◽  
Random Vibration ◽  
Element Model ◽  
Vibration Testing ◽  
Time Data ◽  
Power Spectral ◽  
The Impact

Today, freight is an extremely important industry for the world we are living. Fast transportation, large volume...will optimize the cost, time and effort. Besides, ensuring the products safety is a matter of concern. During transporting, it is inevitable that the vibration caused by the engine, rough road surface...the cargo inside can be damaged. Automobile industries have prime importance to vibration testing. Sine vibration testing is performed when we have been given with only one frequency at given time instant. Trend to perform random vibration testing has been increased in recent times. As random vibration considers all excited frequencies in defined spectrum at known interval of time, it gives real-time data of vibration severities. The vibration severity is expressed in terms of Power Spectral Density (PSD). KLT box is an industrial stacking container conforming to the VDA 4500 standard that was defined by German Association of the Automotive Industry (VDA) for the automotive industry. The aim of this paper is study about random vibration and power spectral density analysis, how it can be used to predict the impact of hash road to the KLT box on container / truck during transportation. Finite element model is developed in ANSYS, modal analysis and random vibration analysis were done.

scholarly journals Impact of Tracheal Tube on Swallowing in Post-Operative Head and Neck Cancer Patients: Scintigraphic Analysis

Dysphagia ◽  
2020 ◽  
Author(s):  
Jacopo Galli ◽  
Maria Raffaella Marchese ◽  
Tiziana Di Cesare ◽  
Laura Tricarico ◽  
Giovanni Almadori ◽  
...  
Keyword(s):  
Head And Neck Cancer ◽  
Head And Neck ◽  
Cancer Patients ◽  
Tracheal Tube ◽  
Transit Time ◽  
Neck Cancer ◽  
Retention Index ◽  
Small Diameter ◽  
Swallowing Rehabilitation ◽  
The Impact

AbstractDysphagia is common in tracheostomized patients who underwent head and neck surgery for cancer treatment. The objective of this study was to evaluate, by means of oropharyngoesophageal scintigraphy (OPES), the impact of an occluded tracheal tube (TT) on swallowing in patients treated for head and neck cancer before hospital discharge, to provide further information to the benefit of out-patient care management. From October 2018 to November 2019, we enrolled 19 tracheostomized patients (6 females and 13 males; mean age 61 years) who underwent primary surgical resection of head and neck tumor and swallowing rehabilitation during hospitalization. All subjects underwent a double-standard OPES, one with occluded tracheal tube and the other without TT, with their tracheal stoma being closed directly by a plaster. For each study, we assessed and compared the following quantitative parameters: oral transit time (OTTsec), pharyngeal transit time (PTTsec), esophageal transit time (ETTsec), oral retention index (ORI%), pharyngeal retention index (PRI%), esophageal retention index (ERI%), and aspiration percentage (AP%). The mean values of OTT, PTT, ORI%, PRI%, and ERI% were abnormal during OPES both with TT and without TT and did not statistically differ between the two tests (p > 0.05). Aspiration was detected in 4 cases out of 19 (21.05%) cases during OPES with TT and in 4/19 (21.05%) cases without TT who showed a mean AP% of 11.4% and 11.5% respectively (p > 0.05). Patients with abnormal AP% (> 0%) during OPES with TT showed aspiration signs without TT. Our study showed that the mere presence of a closed tracheal tube does not impact significantly the oropharyngeal transit of bolus during swallowing. This result suggests the possibility to maintain a small-diameter occluded tracheal tube in place for the postsurgical management of head and neck cancer patients.

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