Stress and Vibration Analysis of a Lathe Bed Made of Aluminum-Copper Alloy for High Speed Machining

2009 ◽  
Vol 15 ◽  
pp. 81-88 ◽  
Author(s):  
R. Torres-Martínez ◽  
G. Urriolagoitia-Calderón ◽  
G. Urriolagoitia-Sosa ◽  
R. Espinoza-Bustos
Keyword(s):  
Cast Iron ◽  
High Speed ◽  
Natural Frequencies ◽  
Mechanical Design ◽  
Parametric Modeling ◽  
High Speed Machining ◽  
The Finite Element Method ◽  
Cu Alloy ◽  
Design Variables ◽  
Machine Tool Structure

The analysis of the rigidity of an Al-Cu alloy lathe bed to be used for high speed machining (HSM) is presented in this work. Mechanical design optimization by means of simulations based on the finite element method (FEM) was applied in order to calculate the lathe bed deflections, the natural frequencies and the corresponding vibration amplitudes. For the parametric modeling, a prototype lathe to be used in conventional speed machining (CSM) with a cast iron bed was considered. The optimized parameter was the stress in the lathe bed, considering as a restriction the allowable deflection in a node of the machine-tool structure. The design variables were the height, the thickness, and the length of the wall of the lathe bed. The lathe bed was loaded with cutting and inertial forces due to HSM in order to demonstrate that the evaluated stresses and vibration amplitudes are in an acceptable level according to ISO Standards (system of limits and fits in workpieces). The results show the feasibility of using an Al-Cu alloy instead of cast iron in the fabrication of lathe beds. This increases the flexibility of manufacture.

Computation and Analysis of Unbalancing Responses of High Speed Machining Tool System

2010 ◽  
Vol 148-149 ◽  
pp. 40-46 ◽  
Author(s):  
Chun Gen Shen ◽  
Gui Cheng Wang ◽  
Shu Lin Wang ◽  
Wen Wu Nie ◽  
Gang Liu
Keyword(s):  
Modal Analysis ◽  
High Speed ◽  
Natural Frequencies ◽  
Experimental Modal Analysis ◽  
Dynamic Responses ◽  
High Speed Machining ◽  
The Finite Element Method ◽  
Complex Dynamic ◽  
Fem Model ◽  
Integrated Methodology

In this study, an integrated methodology combining computational modal analysis, experimental modal analysis, and computational dynamic analysis was developed to investigate unbalancing dynamic responses of high speed machining tool systems. A linear-elasticity formulation based on the finite element method (FEM) was employed to compute the natural frequencies and obtain the corresponding modal shapes. Experimental modal analysis was then performed to verify the natural frequencies. After the validation, the FEM model was further modified to predict the dynamic responses, with an HSK (a Germany abbreviation of Hohl Schaft Kegel) tool system as a model system. The results indicated that, by validating the computed natural frequencies with experimental ones, an effective simulation model can be established for predicting complex dynamic response of high speed machining tool systems.

Surface Integrity of a High Speed Milling FC300 Gray Cast Iron

2013 ◽  
Vol 465-466 ◽  
pp. 642-646 ◽  
Author(s):  
Abu Bakar Mohd Hadzley ◽  
Mohamad Raffi Nurul Fatin ◽  
Raja Abdullah Raja Izamshah ◽  
Nur Izan Syahriah Hussein ◽  
Ahmad Siti Sarah ◽  
...  
Keyword(s):  
Cast Iron ◽  
Automotive Industry ◽  
High Speed ◽  
Gray Cast Iron ◽  
Gray Cast ◽  
Surface Finishing ◽  
High Speed Machining ◽  
High Productivity ◽  
Die Surface ◽  
End Mills

The high speed machining (HSM) of gray cast iron for manufacture mold and dies involve many different cutting tool from deep hole drills to smallest ball nose end mills [. Due to the demand of fast and high productivity, high speed machining (HSM) has been increasingly used to produce mold and dies that are mostly used in automotive industry especially for stamping dies components. The process of HSM sometimes combined together with manual polishing to enhance the die surface into fine mirror finish. Although the manual polishing strongly depends by experience and skill of workers, this technique is the preferable option for polishing of moulds and dies. However, such extensive manual polishing will provide some drawback because of many human factors such as pressure and technique of polishing individual person uses. Therefore, the application high speed machining in manufacturing is still demanding as it can improve surface finishing by reducing manual polishing, reportedly account for up to 30% of the total time [2].

Performances of HSK Spindle/Toolholder Interface for HSM

2006 ◽  
Vol 532-533 ◽  
pp. 269-272
Author(s):  
Song Zhang ◽  
Xing Ai ◽  
Jian Feng Li ◽  
Xiu Li Fu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress Distribution ◽  
Contact Stress ◽  
High Speed ◽  
Rapid Development ◽  
High Speed Machining ◽  
The Finite Element Method ◽  
Axial Movement ◽  
Contact Stress Distribution

With the rapid development of high-speed machining technology, more and more machining centers have been equipped with the HSK toolholders. In this paper, the performances of the HSK spindle/toolholder interface, such as the axial movement, the radial deflection and the contact stress distribution, were simulated by means of the finite element method and compared with the traditional BT interface. From the simulated results, it was pointed out that the performances of the HSK interface were obviously superior to that of the BT interface, and the HSK interface was much more suitable for high-speed machining.

Unbalance Response of HSK Hydraulic Chuck Tooling System for High-Speed Machining

2016 ◽  
Vol 836-837 ◽  
pp. 387-393
Author(s):  
De Fei Tao ◽  
Deng Sheng Zheng ◽  
Jian Chen ◽  
Gui Cheng Wang
Keyword(s):  
High Speed ◽  
Linear Growth ◽  
Excitation Frequency ◽  
Numerical Control ◽  
High Speed Machining ◽  
The Finite Element Method ◽  
Displacement Response ◽  
Tooling System ◽  
Balancing Control

High-speed chuck is an important component of high speed machining tooling system. Its properties directly affect the performance and processing quality of advanced numerical control machine. Using the finite element method, the research analyzed influence of inertial centrifugal force caused by unbalance on the dynamic characteristics of HSK hydraulic clamping chuck tooling system and systematically revealed variation of shank, chuck and blade point displacement. It is found that blade point, as well as chuck and shank displacement response amplitude of tooling system rises as a whole with the increase of excitation frequency; the dynamic displacement response increment shows linear growth with unbalance amount, which provides a theoretical basis for optimum design and balancing control of HSK hydraulic chunk tooling system.

Experimental Research on High-Speed Machining Pearlitic Gray Cast Iron

2006 ◽  
Vol 315-316 ◽  
pp. 459-463 ◽  
Author(s):  
Yi Wan ◽  
Zhan Qiang Liu ◽  
Xing Ai
Keyword(s):  
Cast Iron ◽  
High Speed ◽  
Cutting Tool ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
High Speed Machining ◽  
Workpiece Surface ◽  
Tool Materials ◽  
Boron Nitrogen

High-speed machining (HSM) has received great interest because it leads to an increase of productivity and a better workpiece surface quality. However, tool wear increases dramatically due to the high temperature at the tool/workpiece interface. Proper selection of cutting tool and cutting parameters is the key process in high-speed machining. In this paper, experiments have been conducted to high speed milling pearlitic cast iron with different tool materials, including polycrystalline cubic boron nitrogen, ceramics and coated cemented carbides. Wear curves and tool life curves have been achieved at various cutting speeds with different cutting tools. If efficiency is considered, Polycrystalline Cubic Boron Nitrogen cutting tool materials are preferred in finish and semi-finish machining. According to the different hardness of cast iron, the appropriate range of cutting speed is from 850 m/min to 1200m/min.

On the Vibration of Coupled Traveling String and Air Bearing Systems

1996 ◽  
Vol 118 (3) ◽  
pp. 398-405 ◽  
Author(s):  
A. V. Lakshmikumaran ◽  
J. A. Wickert
Keyword(s):  
High Speed ◽  
Natural Frequencies ◽  
Nodal Point ◽  
Fold Increase ◽  
Computational Effort ◽  
Air Pressure ◽  
Mode Shapes ◽  
Air Bearing ◽  
Design Variables ◽  
Axially Moving

Air bearings are used to position and guide such axially-moving materials as high speed magnetic tapes, paper sheets, and webs. In each case, vibration of the moving medium couples with the air bearing’s dynamics, and techniques are developed here to reduce the computational effort that is required to predict the natural frequencies, damping ratios, and vibration modes of the prototypical traveling string and self-pressurized air bearing model. Automatic nodal point allocation reduces the number of nonlinear equations that arise in finding the equilibrium string displacement and air pressure, and in subsequent vibration analysis, the response is obtained in closed form by using the Green’s function for the traveling string. Global discretization of the air pressure alone then yields a matrix eigenvalue problem which is simpler than that obtained through previous methods which required discretization of both displacement and pressure. Overall, essentially a five-fold increase in computational speed is achieved, thus facilitating design and parameter studies. Changes in the natural frequencies, damping ratios, and coupled displacement-pressure mode shapes with respect to several design variables are discussed and compared with experiments.

The Effect of Dynamic Consistency in Spindles on Cutting Performance

2000 ◽  
Author(s):  
Scott Smith ◽  
W. R. Winfough ◽  
Keith Young ◽  
Jeremiah Halley
Keyword(s):  
Machine Tool ◽  
High Speed ◽  
Natural Frequencies ◽  
Cutting Performance ◽  
Dynamic Consistency ◽  
High Speed Machining ◽  
Flexible Tool ◽  
Significant Variability ◽  
Rotational Orientation

Abstract This paper presents the results of three measurements of dynamic consistency in machine tool spindles. First the effect of reclamping and of the rotational orientation of a tool in a single spindle (40,000 rpm 40 kW) was evaluated. Then 5 different spindles of the same model (20,000 rpm 75 kW) were compared, first with a flexible tool and then with a stiff tool. It was seen that in all the tests the natural frequencies did not vary greatly, but that in some situations the damping showed significant variability. The effect of this damping variation on stability and cutting performance is evaluated for both conventional and for high speed machining.

On the Taper Interference Fit in the HSK Spindle/Toolholder Interface

2007 ◽  
Vol 339 ◽  
pp. 95-99 ◽  
Author(s):  
Song Zhang ◽  
Xing Ai ◽  
Jian Feng Li ◽  
Xiu Li Fu
Keyword(s):  
Finite Element Method ◽  
Stress Distribution ◽  
Contact Stress ◽  
High Speed ◽  
High Speed Machining ◽  
The Finite Element Method ◽  
Interference Fit ◽  
Partial Contact ◽  
Nonlinear Contact ◽  
Contact Stress Distribution

The HSK spindle/toolholder interface belongs to the complicated nonlinear contact problem caused by taper interference fit. The experiment and the traditional Lame's equation are all not suited for analyzing the contact stress distribution and deformation in the spindle/toolholder interface. In this paper, the contact stress distribution and the deformation of the HSK-A63 spindle/toolholder interface caused by the taper interference fit were precisely simulated by means of the finite element method. The simulated results showed that the toolholder shank was in partial contact with the spindle bore, the interference specified by ISO was not enough for the high-speed machining and larger interference should be introduced.

FEM-Based Dynamic Performances of HSK Spindle/Toolholder Interface

2010 ◽  
Vol 431-432 ◽  
pp. 142-145
Author(s):  
Song Zhang ◽  
Xing Ai
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Dynamic Modeling ◽  
Rotational Speed ◽  
High Speed ◽  
Natural Frequencies ◽  
Contact Stiffness ◽  
High Speed Machining ◽  
Structural Damping ◽  
Dynamic Performances

In the present paper, a dynamic modeling approach is presented to determine the contact stiffness and structural damping between the spindle and the toolholder; and then, the spindle and the toolholder are coupled by some springs and dampers. Finally, the dynamic performances of the HSK-A63 spindle/toolholder interface are analyzed by means of finite element method (FEM). From the simulated results, it can be seen that the natural frequencies of the first two modes increase with the increase of the rotational speed, which make the HSK spindle/toolholder interface appear good dynamic performances and be suitable for high-speed machining.

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