scholarly journals Vibration Control of Weakly Rigid Casing Based on Gasbag-rubber Damping Flexible Fixture

2021 ◽  
Author(s):  
Xiaohua Zhu ◽  
Yao Zhang ◽  
Tian Li ◽  
Liangliang Dong ◽  
Junlei Tang ◽  
...  
Keyword(s):  
Vibration Control ◽  
Research Work ◽  
Nonlinear Problems ◽  
Vibration Damping ◽  
Machining Process ◽  
Processing Efficiency ◽  
Factors Affecting ◽  
New Type ◽  
Thin Walled ◽  
Fixture System

Abstract Combustion chamber casing is a key component of aeroengine, because of its poor rigidity, severe chattering occurs during milling, which seriously affects the surface quality and processing efficiency of the casing, and the existence of geometric nonlinear problems in the machining process makes it difficult to predict machining vibration. Therefore, it is of great significance to study the vibration law of thin-walled casing and reduce machining vibration. Aiming at the problem of vibration control of thin-walled casing, this paper proposes a new type of gasbag-rubber damping flexible fixture, which differ from the ordinary rigid fixture, this fixture has adjustable clamping force and good vibration damping ability. The key factors affecting the vibration response of the thin-walled casing are studied through establishing an equivalent dynamic model of the workpiece-fixture system. The research results show that the gasbag-rubber damping flexible fixture can effectively provide support stiffness, which is beneficial to reduce the vibration of the workpiece during processing; According to the actual thickness of different workpieces, the appropriate gasbag pressure is recommended to give play to the vibration damping performance of the fixture; It is recommended that the thickness of the rubber damping block in practice is 8~12mm. The research work in this paper has important guiding significance for the design and use of the gasbag-rubber damping flexible fixture, and provides an effective theoretical prediction for the vibration of the thin-walled casing.

scholarly journals Experimental study on cutting parameters and machining paths of SiCp/Al composite thin-walled workpieces

2020 ◽  
Vol 29 ◽  
pp. 2633366X2094252
Author(s):  
Yunan Liu ◽  
Shutao Huang ◽  
Keru Jiao ◽  
Lifu Xu
Keyword(s):  
Cutting Force ◽  
Volume Fraction ◽  
Cutting Speed ◽  
Aluminum Matrix ◽  
Machining Process ◽  
Cutting Depth ◽  
Processing Efficiency ◽  
Al Composite ◽  
Edge Defects ◽  
Thin Walled

Thin-walled workpieces of silicon carbide particle-reinforced aluminum matrix (SiCp/Al) composites with outstanding properties have been widely applied in many fields, such as automobile, weapons, and aerospace. However, the thin-walled workpieces exhibit poor rigidity, large yield ratio, and easily deform under the cutting force and cutting heat during the machining process. Herein, in order to improve the processing efficiency and precision of higher volume fraction SiCp/Al composite thin-walled workpieces, the influence of different high-speed milling parameters and machining paths on the edge defects is analyzed. The results reveal that the cutting force initially increased and then decreased with the cutting speed. Besides, the cutting force steadily increased with radial cutting depth and feed per tooth, but the influence of feed per tooth is less than radial cutting depth. After up-milling cut-in and cut-out processing and down-milling cut-out processing, the cut-in end of the workpiece exhibited higher breakage and obvious edge defects. However, the workpiece edges remained intact after down-milling cut-in processing. In conclusion, a higher cutting speed, a smaller radial cutting depth, and moderate feed per tooth are required to decrease the cutting force during the milling of SiCp/Al composite thin-walled workpiece. Furthermore, down-milling cut-in processing mode can reduce the edge defects and improve the processing efficiency and precision of the workpiece.

Experimental Investigation on Boring Tool Vibration Control Using MR Fluid Damper

2016 ◽  
Vol 15 (01) ◽  
pp. 13-25 ◽  
Author(s):  
E. Mohan ◽  
U. Natarajan
Keyword(s):  
Vibration Control ◽  
Research Work ◽  
Machining Process ◽  
Work Piece ◽  
Mr Fluid ◽  
Tool Vibration ◽  
Fluid Damper ◽  
Boring Tool ◽  
Mr Fluid Damper

In the manufacturing industry, most of the components are made by machining operations. The performance of the product to a large extent is dependent on the accuracy and consistency of the machining processes. Various parameters are considered to achieve the high quality of the machining. Out of which, vibration is one of the important parameters that will lead poor quality of the product and also reduce the tool life. Vibrations are induced by metal cutting operation during machining. Turning operations and especially boring operations are associated with severe vibration-related problems. Boring operation is often done with a boring bar, which is necessarily long and slender so that it can fit into the multipart work piece geometry. Such tools are lack of dynamic stiffness and stability, this manufacturing operation is repeatedly plagued with self-excited vibrations known as chatter. Magnetorheological (MR) fluid is employed in this research work to control the vibration of a boring tool. The MR fluid damper has received great attention due to its ability to reversibly change from a free flowing, linear, viscous liquid to a semi-solid when exposed to magnetic fields in just a few milliseconds and was also found to be effective in suppressing tool vibration. Vibration control during machining process is an important tactic to suppress the chatter vibration. The aim of this approach is to reduce the relative displacements between the tool and the work piece during the machining process.

Air Thin-Walled Parts Machining Precision Control

2014 ◽  
Vol 496-500 ◽  
pp. 1252-1255
Author(s):  
Liang Li
Keyword(s):  
Structural Characteristics ◽  
Complex Structure ◽  
Machining Process ◽  
Aviation Industry ◽  
Precision Machining ◽  
Thin Wall ◽  
Processing Efficiency ◽  
Precision Control ◽  
Machining Precision ◽  
Thin Walled

With the development of the aviation industry, the aircraft's increasingly high performance requirements, the overall application of thin-walled structural components became more widespread. However, due to the complex structure parts, thin wall, high precision machining process was complexity, the cutting force, cutting heat, clamping force under the influence of other factors, prone to machining distortion, and with the lower part wall thickness, decreased in rigidity, it was difficult to ensure processing quality. In this paper, we proposed several effective aviation thin-walled parts machining precision control program to solve the problems in the processing of machine structural characteristics of thin-walled parts .The results of experiments and production practice proved that these methods effectively control the air thin-walled parts machining precision machining to meet quality requirements, while reducing the processing time, improve processing efficiency, it was convenient and efficient processing methods.

scholarly journals Prediction of Frequency Response Function for Cylindrical Thin-Walled Workpiece with Fixture Support Constraints

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Jinjie Jia ◽  
Yuwen Sun ◽  
Jinbo Niu
Keyword(s):  
Frequency Response ◽  
Response Function ◽  
Frequency Response Function ◽  
Machining Process ◽  
Analytical Mechanics ◽  
Efficient Prediction ◽  
Thin Walled ◽  
Vector Mechanics ◽  
Fixture System ◽  
Variable Separation Method

Auxiliary fixtures are widely used to enhance the rigidity of cylindrical thin-walled workpieces (CTWWs) in the machining process. Nevertheless, the accurate and efficient prediction of frequency response function (FRF) for the workpiece-fixture system remains challenging due to the complicated contact constraints between workpiece and fixture. This paper proposes an analytical solution for the comprehensive FRF analysis of the CTWW-fixture system. Firstly, based on the vector mechanics, the mode shape functions of the workpiece are presented using the classical theory of thin shell. The variable separation method is utilized to deal with the inter-mode coupling of the workpiece. Secondly, the motion equation of the CTWW with fixture constraints is established using analytical mechanics from the viewpoint of energy balance. Finally, the FRFs of the CTWW-fixture system are derived by means of modal superposition. Experimental modal tests verify that the predicted FRFs are in good agreement with the measured curves.

Preparation and characterization of magnetorheological elastic polishing composites

2019 ◽  
Vol 30 (10) ◽  
pp. 1481-1492 ◽  
Author(s):  
Zhiqiang Xu ◽  
Qiuliang Wang ◽  
Kejun Zhu ◽  
Shengqiang Jiang ◽  
Heng Wu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Testing Machine ◽  
Optical Microscope ◽  
Scratch Resistance ◽  
Machining Process ◽  
X Ray Diffraction ◽  
Processing Efficiency ◽  
New Type ◽  
The Magnetic Field

Magnetorheological elastic polishing composites, a new type of polishing material using magnetorheological elastomers as a binder, were developed to solve the problems of low processing efficiency and difficulty controlling the machining process in current polishing technology. A set of heat–magnet–force-coupled devices was designed and used to prepare isotropic and anisotropic silicon rubber–based magnetorheological elastic polishing composites by magnetic field–assisted compression molding technology. Then, the microstructure and properties of magnetorheological elastic polishing composites were characterized by X-ray diffraction, optical microscope, electronic universal testing machine, and microscratch tester. The results show that magnetorheological elastic polishing composite is a polymer-based composite composed of rubber and micro/nanoparticles, and the magnetic field applied during the preparation process causes the interior of the magnetorheological elastic polishing composites to appear as chains and columns formed by iron particles. The compressive elastic modulus and scratch resistance of magnetorheological elastic polishing composites increase with the increase in the surrounding magnetic field strength. The main reason for the above phenomena is related to the change in the microstructure of magnetorheological elastic polishing composites induced by an external magnetic field. Finally, a simple application of magnetorheological elastic polishing composites in polishing proves that magnetorheological elastic polishing composites can be applied to mechanical processing to achieve magnetically controlled polishing.

Optimization of Machining Process for Aluminum Alloy Thin-Walled Supporting Part on UG NX

2010 ◽  
Vol 129-131 ◽  
pp. 246-250
Author(s):  
Yi Shu Hao ◽  
Bao Gang Zhang ◽  
Xu Cui
Keyword(s):  
Aluminum Alloy ◽  
Process Parameters ◽  
Tool Path ◽  
Structural Features ◽  
Machining Process ◽  
Machining Simulation ◽  
Processing Efficiency ◽  
Productivity Cost ◽  
Process Plan ◽  
Thin Walled

According to the structural features of the supporting part, the manufacturing process plan of it is made and the fixtures are designed. The process parameters are optimized by the means of setting up multi-objective function that cover productivity, cost of production, processing efficiency; The NC Programs of supporting part are drawn with UG CAM and the machining tool-path is optimized through machining simulation.

Cut Flowers Being Sold as Impulse Items: A Look at Factors Affecting Impulse Product Merchandising

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 558c-558
Author(s):  
Jennifer B. Neujahr ◽  
Karen L.B. Gast
Keyword(s):  
Consumer Behavior ◽  
Marketing Strategies ◽  
Easy Access ◽  
Future Research ◽  
Grocery Stores ◽  
Cut Flowers ◽  
Factors Affecting ◽  
New Type ◽  
The 1950S ◽  
The Way

Consumer behavior research seems to play an big role in determining the wants and needs of an industry. This research helps to shape the way we market to the consumers and helps make marketing strategies more effective. In the 1950s grocery stores began to sell horticulture products in order to alleviate the growers' surplus. Supermarkets now have seem to found their niche in this market due to the fact that they can influence their consumers to buy their flowers right along with their bread, and get all of their shopping done at once. This new type of sale, commonly referred to as the impulse sale, can relate directly to how well the store is merchandised and maintained. A study was conducted at a local supermarket, to determine the following: good locations for impulse sales items, special conditions affecting impulse sales items, and what types of things could affect demand for impulse items. It was discovered that certain locations make better sales than other locations. Locations that were front and center and allowed easy access to seeing the mixed flower bouquet without having to touch it yielded the best results. The variables used to show a change in demand showed little to some variability and has raised some questions which may be used to conduct future research.

Experiment Study of Oil-Air Lubrication on Cooling of Turning Tools

2011 ◽  
Vol 189-193 ◽  
pp. 3187-3190 ◽  
Author(s):  
Jin Li Wang ◽  
Lin Cai ◽  
Hong Tao Zheng
Keyword(s):  
Metal Cutting ◽  
Research Work ◽  
Cutting Temperature ◽  
Cost Savings ◽  
Machining Process ◽  
Dry Cutting ◽  
Air Lubrication ◽  
Temperature Contrast ◽  
Cooling Technology ◽  
Lubrication Conditions

When lubricants are used according to special requirements, it is possible to achieve considerable cost savings. Compared to conventional coolant cooling technology used in metal cutting, oil-air lubrication increases cooling performance, avoids environmental pollution, reduces running and maintenance costs. The cutting temperature contrast experimental research was based on close to practice 45# steel in dry cutting, wet cutting and oil-air lubrication conditions. The research work concentrated on the superiority of oil-air lubrication cooling and the influence of cutting amount on temperature. The experimental results show that oil-air lubrication is more effective in reducing the cutting temperature than wet cutting or dry cutting, this paper details the cutting temperature curves at several different tests provides a basis for industrial production, improves the level of machining process and the significance was being reported.

Digital Twin-driven machining process for thin-walled part manufacturing

2021 ◽  
Vol 59 ◽  
pp. 453-466
Author(s):  
Zexuan Zhu ◽  
Xiaolin Xi ◽  
Xun Xu ◽  
Yonglin Cai
Keyword(s):  
Machining Process ◽  
Digital Twin ◽  
Thin Walled

scholarly journals Factors Affecting the Compression and Energy Absorption Properties of Small-Sized Thin-Walled Metal Tubes

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Xiaoqin Hao ◽  
Jia Yu ◽  
Weidong He ◽  
Yi Jiang
Keyword(s):  
Energy Absorption ◽  
Simulation Models ◽  
Simulation Method ◽  
Engineering Practice ◽  
Small Ring ◽  
Metal Tube ◽  
Absorption Properties ◽  
Factors Affecting ◽  
Thin Walled ◽  
Hollow Metal

To solve the problem of the effective cushioning of fast-moving mechanical components in small ring-shaped spaces, the factors affecting the compression and energy absorption properties of small-sized hollow metal tubes were studied. Simulation models were constructed to analyse the influences of tube diameter, wall thickness, relative position, and number of stacked components on the compression and energy absorption properties. The correctness of the simulation method and its output were verified by experiments, which proved the effectiveness of compression and energy absorption properties of small-sized thin-walled metal tubes. The research provides support for the application of metal tube buffers in armament launch technology and engineering practice.

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