scholarly journals Influence of Selected Diagnostic Parameters on the Quality of AWJ Cutting Surface

2022 ◽  
Vol 16 (1) ◽  
pp. 129-140
Author(s):  
Tomasz Wala ◽  
Krzysztof Lis
Author(s):  
Liping Wang ◽  
Binbin Zhang ◽  
Jun Wu ◽  
Qinzhi Zhao ◽  
Junjian Wang

The stiffness of a spindle at high speeds has a significant effect on the quality of the cutting surface and the machining accuracy. However, the spindle stiffness is difficult to be detected directly when the spindle is rotating, and the measured stiffness values are usually coupled with other parts of the spindle–tool system (such as toolholder, spindle–toolholder joint, tool). This paper presents a comprehensive method to deal with the stiffness modeling, identification, and measuring of a rotating spindle. Based on the deflection equation and the principle of superposition, the stiffness model is derived, for a spindle–tool system including a spindle, a specially manufactured toolholder, and a spindle–toolholder joint. A three-step identification algorithm is proposed to decouple and identify the actual spindle stiffness value. First, when the spindle is static, the stiffness values of the shaft, toolholder, and joint are obtained by using the least-squares method. Second, when the spindle is rotating, the stiffness values of the rear bearings and front bearings are identified based on the spindle error analysis method. Third, the stiffness values of the spindle under different rotating conditions are calculated based on the identification results from the previous two steps. Furthermore, the stiffness model and identification algorithm are verified experimentally on an instrumented spindle. The static stiffness value of the same spindle is also measured and compared with the stiffness value under rotating conditions subsequently. This work is useful and can be utilized as a guide for spindle stiffness testing and spindle performance evaluation to spindle manufacturers.


2015 ◽  
Vol 8 (1) ◽  
pp. 37-42 ◽  
Author(s):  
Aleksandrs Gasparjans ◽  
Aleksandrs Terebkovs ◽  
Anastasia Zhiravetska

Abstract A method of technical diagnostics of ship diesel engine – generator installation – is proposed. Spectral-power diagnostic parameters of the synchronous generator voltage and currents are used. The electric machine in this case is the multipurpose sensor of diagnostic parameters. A judgment on the quality of the operational processes in diesel engine cylinders and its technical condition is possible on the basis of these parameters. This method is applicable to piston compressor installations with electric drive. On the basis of such parameters as rotating torque, angular speed and angular acceleration it is possible to estimate the quality of the operating process in the cylinders of a diesel engine, the condition of its cylinder-piston group and the crank gear mechanism. The investigation was realized on the basis of a diesel-generator with linear load. The generator operation was considered for the case of constant RL load. Together with the above mentioned, the condition of bearings of synchronous machines, uniformity of the air gap, windings of the electric machine were estimated during the experiments as well. The frequency spectrum of the stator current of the generator was researched and analyzed. In this case the synchronous machine is becoming a rather exact multipurpose diagnostic sensor. The signal of non-uniformity in the operation process of diesel engine cylinders and its technical condition is the increasing of the amplitudes of typical frequencies.


2014 ◽  
Vol 974 ◽  
pp. 389-393 ◽  
Author(s):  
Sen Liu ◽  
Dong Mei Wu ◽  
Jun Zhao

In orthopedic surgery, it is easy to do harm to surrounding tissues, so the study of bone cutting is necessary. In this article, a finite element model (FEM) of orthogonal bone cutting is developed. Cutting force intra-operatively can provide the surgeon with additional on-line information to support him to control quality of cutting surface. The obtained cutting force decreased little with cutting speed increasing, but ascended evidently with cutting depth increasing. The results of finite element simulations are aimed at providing optimization of cutting parameters and the basic information for hybrid force-velocity control of a robot-assisted bone milling system.


2013 ◽  
Vol 652-654 ◽  
pp. 2369-2373
Author(s):  
Gui Min Yin ◽  
Zhan Guo Li ◽  
Meng Li

Using high power Nd3+:YAG pulse laser for precision cutting stainless sheet, study the effects of the laser cutting technological parameters on quality of cutting surface and joint-cutting width. The data of single factor experiment proved: With the increasing of scanning velocity, the joint-cutting width decreased; the width increased with the increasing of scanning velocity, laser current, impulse frequency and impulse width; the increasing of impulse frequency may improve the processing quality and ultimate cutting speed; the data of two-factors experiment proved: when the output power and impulse width are fixed, the impulse frequency will be increased, the joint-cutting width will be decreased; when the output power and impulse frequency are fixed, the impulse width will be increased, the joint-cutting width will be decreased.


Author(s):  
Алексей Морозов ◽  
Aleksey Morozov ◽  
Владимир Гусев ◽  
Vladimir Gusev

Grinding disks with high frequency discretization of a cutting surface allow not only breaking a cutting process and de-creasing its thermal intensity, but decreasing a vibration level of a technological system which has a positive effect upon quality of a surface worked. But, for realization of intensive grinding modes these tools should possess a mechanical strength not only in the central hole, but that of a discrete cutting surface. In this connection in modern CAE-complex CosmosWorks a computer simulation of a stressed state of a cutting surface and a central hole of the grinding disk subjected to a high-frequency discretization is carried out. On the basis of the simulation results there is developed a durable tool allowing the fulfillment of discrete grinding in intensive modes.


2019 ◽  
Vol 2 (02) ◽  
pp. 19-24
Author(s):  
Kasijanto Kasijanto ◽  
Sadar Wahjudi ◽  
Listiyono Listiyono ◽  
Muhammad Fakhruddin

Metal cutting process (cutting process) is to cut metal to get the shape and size and quality of the planned cutting surface. The metal cutting process is carried out with special tools, according to the type of cutting process. So the tools for one process cannot be used in another process, even for similar processes, the tools cannot be exchanged if the cutting plans are not the same. Lathe process is a machining process to produce cylindrical machine parts which are carried out using a Lathe. Its basic form can be defined as the machining process of the outer surface of cylindrical or flat lathe objects. Polyvinyl Chloride, commonly abbreviated as PVC, is the third-order thermoplastic polymer in terms of total usage in the world, after Polyethylene (PE) and Polypropylene (PP). Worldwide, more than 50% of PVC produced is used in construction. PVC is produced by polymerizing vinyl chloride monomers (CH2 = CHCl). Because 57% of its mass is chlorine, PVC is the polymer that uses the lowest petroleum feedstock among other polymers. This research follows up the selection of configuration of the lathe machining process using plastic work pieces. In this study, Maximat V13 lathe and PVC type plastic were used. The variation of machining processes are spindle rotation (320, 540, and 900 rpm), feeding speed (0.07, 0.14, and 0.28), the use of tool types (carbide and HSS) and cooling (without cooling, coolant, and oil). So, with this research, it is expected that the optimal parameters in determining the configuration of the lathe machining process on a PVC work piece to produce a good turning surface can be achieved  


HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 1051B-1051
Author(s):  
Jinhe Bai ◽  
Kristi Barckley ◽  
John Manthey

Pear texture is similar to that of apple—firm and crispy—and is one of the potential alternatives to apple. However, at a crispy stage the taste is flat. Improving the taste of pears is considered the key to the success of pear salad. This study evaluated the effect of harvest maturity on the quality of pear salad. Fruit were harvested at commercial maturity or 1 month delayed. After 2 and 5 months (1 and 4 months for delayed harvested fruit) of storage at –1 °C, fruit were sliced (eight to 10 wedges per fruit), treated with an anti-browning dip, packaged in zip-lock bags (10 pieces per bag), and stored at 1 °C for up to 21 days. Delayed harvested fruit were larger in size (≈12.5% increase in weight), had lower flesh firmness (≈5 N decrease), lower titratable acidity content (≈20% decrease), and a lower phenolic content (≈45% decrease in pulp). There was no significant difference in soluble solids content. After 2 months of storage, ethylene production and respiration rate were initially lower in delayed harvested fruit in either the intact fruit or cut slices, but tended to similar after 7 days in storage. Sensory evaluation results show that about 80% of the panel preferred delayed-harvested fruit over commercial harvest, especially in terms of visual quality (71% to 92%), sweetness (75% to 93%), taste (69% to 92%), texture of skin (61% to 92%), texture of flesh (53% to 92%), and overall quality (73% to 92%) during 21 days of storage at 1 °C. After 5 months of storage, cutting surface was dry-looking in delayed harvested fruit. However, sensory evaluation showed panels still preferred the delayed-harvested fruit. The results indicate that salad quality of pears can be improved by delaying harvest.


Author(s):  
Dika Surya Rizky Rahayu ◽  
M. Ridha Mak'ruf ◽  
Syaifudin Syaifudin

The lighting of the operating/surgical site depends on the quality of the lighting from the overhead light source and the reflection from the curtain. Light measurement on the operating table is very necessary because it generates light that is irradiated into the cutting wound without dazzling the cutting surface so that pathological conditions can be recognized and must provide depth contrast and anatomical relationships, to ensure this proper calibration method is needed. Long-term use of medical devices can cause changes in accuracy. Therefore, the author makes a tool to measure the intensity of light which is equipped with a distance meter. The purpose of this study was to develop a measuring instrument for measuring the intensity of light in operating lamps, namely a luxmeter by making Luxmeter equipped with a TFT Display Distance Sensor. This tool uses an ultrasonic sensor HC-SR04 to measure the distance between the light source and the sensor module and the MAX44009 sensor to measure the light intensity of the operating lamp displayed on the TFT screen. Based on the module distance setting to the roll meter, the distance error value for the measurement of the Surabaya electromedical engineering workshop lamp at the 75 cm roll meter distance setting is 0.0127% for the 100 cm roll meter distance setting is 0.0045%. The error rate of the light intensity module on the results of the measurement of light intensity on the luxmeter by setting the roll meter distance of 75 cm between the tool and the lamp of the electromedical engineering workshop is getting an error value of 0.082% lux and for the light intensity on the results of the measurement of light intensity on the luxmeter with a roll meter distance setting of 100 cm between the tool and the lamp in the electromedical engineering workshop, that is, the error value of lux is 0.055%. The design of a luxmeter equipped with a proximity sensor can measure the intensity of light and the distance between the tool and the light source and can assist in the learning process with a more effective Luxmeter design that will assist electromedics in testing operating lamps in hospitals to be more efficient.


2001 ◽  
Author(s):  
Juha Inberg ◽  
Jouni Mattila ◽  
Tapio Virvalo

Abstract This paper concentrates on the forest machines, which are working in the cut-to-length method. The cutting function is an essential part of a harvester’s work in the cut-to-length method. The quality of cutting is the most significant feature of a cut. Trees should be cut without causing damage, especially end checks, to the cutting surface of wood. Nowadays end checks of logs are main problem of the cutting process. It has been observed that end checks are found in as many as 70% of the logs. The cutting damages reduce the amount of useful material and cause considerable economical loss to the sawmill and veneer industries. The study deals with the boom lowering function, which is a potential solution to avoid cutting damages during the timber cutting process. The purpose is to momentarily counterbalance the gravitational force of a log during the cross-cut. This paper presents model derivation and analysis of the kinematics, dynamics and hydraulics of the studied forest boom. The paper also shows that the model can be used as a design tool to examine the influences of hydraulics and control system to the behaviour and performance of boom tip acceleration control in a horizontal timber cutting in future studies.


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