Receptance Coupling Study of Tool-Length Dependent Dynamic Absorber Effect

2004 ◽  
Author(s):  
Timothy J. Burns ◽  
Tony L. Schmitz
Keyword(s):  
Frequency Response ◽  
High Speed ◽  
Removal Rate ◽  
Stability Lobe ◽  
Receptance Coupling ◽  
Rapid Prediction ◽  
Substructure Analysis ◽  
Dynamic Absorber ◽  
Receptance Coupling Substructure Analysis ◽  
Free Material

The chatter-free material removal rate during high-speed machining of aluminum using long, slender endmills is limited by the cutting system dynamics, which changes with the tool length. Traditional stability-lobe diagrams that predict the maximum allowable chip width for a given spindle speed are determined using the tool point frequency response function. A brief review is given of a combined analytical and experimental method that uses receptance coupling substructure analysis (RCSA) for the rapid prediction of the tool-point frequency response as the tool length is varied. The basic idea of the method is to combine the measured direct displacement vs. force receptance (i.e., frequency response) at the free end of the spindle-holder system with analytical expressions for the tool receptances. The method is then used to provide an explanation for the dynamic absorber effect that has been observed in the context of tool-length tuning.

Tool Point Frequency Response Prediction for High-Speed Machining by RCSA

2001 ◽  
Vol 123 (4) ◽  
pp. 700-707 ◽  
Author(s):  
Tony L. Schmitz ◽  
Matthew A. Davies ◽  
Michael D. Kennedy
Keyword(s):  
Frequency Response ◽  
High Speed ◽  
Response Prediction ◽  
High Speed Machining ◽  
Receptance Coupling ◽  
Substructure Analysis ◽  
Receptance Coupling Substructure Analysis ◽  
Shrink Fit ◽  
Chatter Stability Prediction ◽  
Analytic Prediction

The implementation of high-speed machining for the manufacture of discrete parts requires accurate knowledge of the system dynamics. We describe the application of receptance coupling substructure analysis (RCSA) to the analytic prediction of the tool point dynamic response by combining frequency response measurements of individual components through appropriate connections. Experimental verification of the receptance coupling method for various tool geometries (e.g., diameter and length) and holders (HSK 63A collet and shrink fit) is given. Several experimental results are presented to demonstrate the practical applicability of the proposed method for chatter stability prediction in milling.

Three-Component Receptance Coupling Substructure Analysis for Tool Point Dynamics Prediction

2005 ◽  
Vol 127 (4) ◽  
pp. 781-790 ◽  
Author(s):  
Tony L. Schmitz ◽  
G. Scott Duncan
Keyword(s):  
Finite Difference ◽  
High Speed ◽  
Experimental Validation ◽  
Second Generation ◽  
Standard Test ◽  
High Speed Machining ◽  
Receptance Coupling ◽  
Substructure Analysis ◽  
Receptance Coupling Substructure Analysis ◽  
Tool Assembly

In this paper we present the second generation receptance coupling substructure analysis (RCSA) method, which is used to predict the tool point response for high-speed machining applications. This method divides the spindle-holder-tool assembly into three substructures: the spindle-holder base; the extended holder; and the tool. The tool and extended holder receptances are modeled, while the spindle-holder base subassembly receptances are measured using a “standard” test holder and finite difference calculations. To predict the tool point dynamics, RCSA is used to couple the three substructures. Experimental validation is provided.

RCSA-Based Method for Tool Frequency Response Function Identification Under Operational Conditions Without Using Noncontact Sensor

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
Rong Yan ◽  
Xiaowei Tang ◽  
Fangyu Peng ◽  
Yuting Li ◽  
Hua Li
Keyword(s):  
Frequency Response ◽  
Response Function ◽  
Frequency Response Function ◽  
Fem Simulation ◽  
Operational Conditions ◽  
Receptance Coupling ◽  
Substructure Analysis ◽  
Cutting Experiment ◽  
Receptance Coupling Substructure Analysis ◽  
The Stability

The stability lobe diagrams predicted using the tool frequency response function (FRF) at the idle state usually have discrepancies compared with the actual stability cutting boundary. These discrepancies can be attributed to the effect of spindle rotating on the tool FRFs which are difficult to measure at the rotating state. This paper proposes a new tool FRF identification method without using noncontact sensor for the rotating state of the spindle. In this method, the FRFs with impact applied on smooth rotating tool and vibration response tested on spindle head are measured for two tools of different lengths clamped in spindle–holder assembly. Based on those FRFs, an inverse receptance coupling substructure analysis (RCSA) algorithm is developed to identify the FRFs of spindle–holder–partial tool assembly. A finite-element modeling (FEM) simulation is performed to verify the validity of inverse RCSA algorithm. The tool point FRFs at the spindle rotating state are obtained by coupling the FRFs of the spindle–holder–partial tool and the other partial tool. The effects of spindle rotational speed on tool point FRFs are investigated. The cutting experiment demonstrates that this method can accurately identify the tool point FRFs and predict cutting stability region under spindle rotating state.

Identification of Toolholder-Spindle Joint Based on Receptance Coupling Substructure Analysis

2013 ◽  
Vol 345 ◽  
pp. 539-542
Author(s):  
Li Jun Zhai ◽  
Xiao Lei Song ◽  
Li Gang Cai
Keyword(s):  
Dynamic Response ◽  
Machine Tool ◽  
Frequency Response ◽  
Spindle Assembly ◽  
Response Functions ◽  
Identification Method ◽  
Receptance Coupling ◽  
Basic Work ◽  
Substructure Analysis ◽  
Receptance Coupling Substructure Analysis

Stiffness identification of toolholder-spindle joint is a basic work for machine tool dynamic research. In this paper, an identification method based on receptance coupling substructure analysis is described. Once the frequency response functions of the toolholder, the spindle and the toolholder-spindle assembly are obtained, the analytical stiffness could be calculated. The method is verified efficiency through dynamic response experiment. Identified stiffness results under different drawbar forces are also discussed.

Tool Point Frequency Response Prediction for Micromilling by Receptance Coupling Substructure Analysis

2017 ◽  
Vol 139 (7) ◽  
Author(s):  
Lu Xiaohong ◽  
Jia Zhenyuan ◽  
Zhang Haixing ◽  
Liu Shengqian ◽  
Feng Yixuan ◽  
...  
Keyword(s):  
Frequency Response ◽  
Response Function ◽  
Frequency Response Function ◽  
Research Work ◽  
Modal Parameters ◽  
Rotational Degree ◽  
Receptance Coupling ◽  
Milling Tool ◽  
Substructure Analysis ◽  
Receptance Coupling Substructure Analysis

One of the challenges in micromilling processing is chatter, an unstable phenomenon which has a larger impact on the microdomain compared to macro one. The minimization of tool chatter is the key to good surface quality in the micromilling process, which is also related to the milling tool and the milling structure system dynamics. Frequency response function (FRF) at micromilling tool point describes dynamic behavior of the whole micromilling machine-spindle-tool system. In this paper, based on receptance coupling substructure analysis (RCSA) and the consideration of rotational degree-of-freedom, tool point frequency response function of micromilling dynamic system is obtained by combining two functions calculated from beam theory and obtained by hammer testing. And frequency response functions solved by Timoshenko's and Euler's beam theories are compared. Finally, the frequency response function is identified as the modal parameters, and the modal parameters are transformed into equivalent structural parameters of the physical system. The research work considers the difference of theoretical modeling between the micromilling and end-milling tool and provides a base for the dynamic study of the micromilling system.

Predicting Tool Point FRF by RCSA in High Speed Milling

2014 ◽  
Vol 1006-1007 ◽  
pp. 398-402
Author(s):  
Kun Long Wen ◽  
Hou Jun Qi
Keyword(s):  
High Speed ◽  
Beam Model ◽  
High Speed Milling ◽  
Receptance Coupling ◽  
Substructure Analysis ◽  
Joint Connection ◽  
Machine Spindle ◽  
Receptance Coupling Substructure Analysis ◽  
Tool Shank ◽  
Euler Bernoulli Beam

Tool point frequency response function (FRF) is the key parameters to predict the milling stability in high-speed milling. Receptance coupling substructure analysis (RCSA) is described to predict the tool point FRF. The major difficulties in RCSA are the identification of joint connection parameters and the obtaining of FRFs of substructure. This paper separation of the milling system into three substructures: the machine-spindle-holder taper, the extended holder-tool shank, and the tool extended portion. Develop the connection model compose of linear and rotational springs and dampers. Determine the substructure FRF by measurement and Euler-Bernoulli beam model. Tool point FRF is obtained by coupling the substructure FRFs through the connection model by RCSA.

A Study of Linear Joint and Tool Models in Spindle-Holder-Tool Receptance Coupling

2005 ◽  
Author(s):  
Timothy J. Burns ◽  
Tony L. Schmitz
Keyword(s):  
Frequency Response ◽  
High Speed ◽  
Nonlinear Least Squares ◽  
Analytical Models ◽  
Connection Matrix ◽  
Depth Of Cut ◽  
Combined System ◽  
Receptance Coupling ◽  
Overhang Length ◽  
Exponential Trend

The dynamics of a spindle-holder-tool (SHT) system during high-speed machining is sensitive to changes in tool overhang length. A well-known method for predicting the limiting depth of cut for avoidance of tool chatter requires a good estimate of the tool-point frequency response (FRF) of the combined system, which depends upon the tool length. In earlier work, a combined analytical and experimental method has been discussed, that uses receptance coupling substructure analysis (RCSA) for the rapid prediction of the combined spindle-holder-tool FRF. The basic idea of the method is to combine the measured direct displacement vs. force receptance (i.e., frequency response) at the free end of the spindle-holder (SH) system with calculated expressions for the tool receptances based on analytical models. The tool was modeled as an Euler-Bernoulli (EB) beam, the other three spindle-holder receptances were set equal to zero, and the model for the connection with the tool led to a diagonal matrix. The main conclusion of the earlier work was that there was an exponential trend in the dominant connection parameter, which enabled interpolation between tip receptance data for the longest and shortest tools in the combined SHT system. Thus, a considerable savings in time and effort could be realized for the particular SHT system. A question left open in the earlier work was: how general is this observed exponential trend? Here, to explore this question further, an analytical EB model is used for the SH system, so that all four of its end receptances are available, and the tool is again modeled as a free-free EB beam that is connected to the SH by a specified connection matrix, that includes nonzero off-diagonal terms. This serves as the “exact” solution. The approximate solution is once again formed by setting all but one SH receptance equal to zero, and the connection parameters are determined using nonlinear least squares software. Both diagonal and full connection matrices are investigated. The main result is that, for this system, in the case of a diagonal connecting matrix, there is no apparent trend in the dominant connecting spring stiffness with tool overhang length. However, in the full connecting matrix case, a general constant trend is observed, with some interesting exceptions.

Stability Prediction during Thin-Walled Workpiece High-Speed Milling

2009 ◽  
Vol 69-70 ◽  
pp. 428-432 ◽  
Author(s):  
Qing Hua Song ◽  
Yi Wan ◽  
Shui Qing Yu ◽  
Xing Ai ◽  
J.Y. Pang
Keyword(s):  
High Speed ◽  
Dynamic Properties ◽  
Removal Rate ◽  
Cutting Parameters ◽  
Milling Process ◽  
Machining Process ◽  
High Speed Milling ◽  
Thin Walled ◽  
Optimization Of Cutting Parameters ◽  
Free Material

A method for predicting the stability of thin-walled workpiece milling process is described. The proposed approach takes into account the dynamic characteristics of workpiece changing with tool positions. A dedicated thin-walled workpiece representative of a typical industrial application is designed and modeled by finite element method (FEM). The workpiece frequency response function (FRF) depending on tool positions is obtained. A specific 3D stability chart (SC) for different spindle speeds and different tool positions is then elaborated by scanning the dynamic properties of workpiece along the machined direction throughout the machining process. The dynamic optimization of cutting parameters for increasing the chatter free material removal rate and surface finish is presented through considering the chatter vibration and forced vibration. The investigations are compared and verified by high speed milling experiments with flexible workpiece.

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