Papers by Author: Guang Yu Tan

Abstract: Cutting temperature is a key factor in impacting the solid carbide end mill’s life, the rule of solid carbide end mill temperature field is the research focus. In this paper, the solid carbide end mill helical side edge is regarded as a helical coil heat source, the tool chip friction surface is considered as a surface heat source which consists of countless helical coil heat source. Based on heat source method, the model of continuous dynamic temperature field simulation of a solid carbide end mills cutting process is established.

Abstract: An Approach that measuring static radial and axial runouts around rotational centre of spindle for cylindrical mills on milling machine was presented, its possible errors coming from imprecise location of gauge were theoretically analyzed. Milling force measuring experiments with variable feeds and cutting depths in low spindle speed was done to estimate the static runouts, these estimated values then were used to test the precision of measured values with this approach. Both results of theoretical analysis and experimental test showed that the relative errors of this measuring approach were small. This approach is to measure the runouts of installed mills, and its measured value is rather precise, its operation is simple, and it needs no special gauge. This approach can be used in study on force of cylindrical mills.

Abstract: In order to reveal the breakage mechanism of flat end mill under periodic thermal shock, transient temperature field model of chisel edge were established by heat source method, transient temperature field model of side edge were established along the sliced differential elements from the bottom of the flute toward the final axial depth of cut by means of line heat source. The simulation results show that transient temperature field prediction model can be used for prediction transient temperature field in high speeding.

Abstract: Time-domain expressions of nominal component and eccentric component that composing horizontal peripheral milling force are derived from geometry of down milling, they are periodic functions with fundamental frequencies same as tooth-frequency and spindle-frequency respectively. By expanding these two time-domain expressions with Taylor series, the frequency-domain description of periheral milling force is obtained. Further mathematical reasoning is exerted on this frequency-domain description, and it proved that as for four-tooth end mills, even-order harmonics of eccentric milling force do not exist, and the amplitude of spindle-frequency component be linear with eccentric distance, but irrelevant with eccentric angle. Above research results imply that the tooth-frequency component of four-tooth end mills is irrelevant with eccentricity, and that eccentric distance can be estimated with amplitudes of tooth-frequency and spindle-frequency components. Results of milling experiment imply that this eccentric-distance estimating method be effective. Spectral characteristics of eccentric milling force for four-tooth end mills are revealed with theory deduction, and the estimation algorithm for eccentric distance with simple calculation is present. Study conclusions can be used in eccentric-geometry estimating and in milling-force modeling.

Abstract: The flow stress change of 3Cr1Mo0.25V steel was researched in this paper through hot compression tests performed in a temperature range from 800 to 900oC and with a strain rate variation from 0.01 to 10s-1. Flow stress constitutive equation was constructed according to true stress-strain curves of 3Cr1Mo0.25V steel. Results indicate that the dynamic recovery is the dynamic softening mechanism of 3Cr1Mo0.25V steel. The flow stress increases with increasing strain rates and decreases with increasing temperature. The rheological behavior of 3Cr1Mo0.25V steel can be characterized by the parameter of Zener-Hollomon in a high temperature range. As for 3Cr1Mo0.25V steel, the activation energy of Q evaluated by the linear regression is about 142.9 kJ/mol.

Abstract: This work aims to investigate parameterized modeling and a different mode of loading with finite element analysis for flat end mill. A loading mode is chosen according to the cutting force model of overall end mills. Normal and shear stresses which calculate from the cutting force experiments are loaded on the rack face of flat end mill. The stress distribution of end mill in high-speed cutting is obtained by finite element analysis. It is shown that the maximum stress is located at major flank face near the tool tip, rather than the nose of tool and the chisel edge. It shows the tool breakage mechanism in the local region. In the end, we compared the finite element analysis results with the experiment ones. It indicates that the analysis results agree well with the experimental data. Therefore, the proposed loading mode is available.

Abstract: This paper adopts with a PMAC Programmable Multi-axis Controller to control a linear motor through adjusting PID + velocity and acceleration feedforward parameters of the control card. The motor can reach 50-nm precision at lower speed. The PLC real-time monitoring function of the software is used to monitor the actual pace of registers. The real-time online adjustment of PID parameters of the motor at various speeds is realized, which makes the motor reach high motion accuracy at various velocity and acceleration.

Abstract: A control method for 100 nm scale motion platform driven by linear servo motors is investigated using a PMAC controller. The control of speed and acceleration is improved by adjusting the PMAC parameters. High-quality speed and acceleration characteristics is obtained, which provides a basis and reference for the application of the platform to high-speed and high-precision feed system.

Abstract: To represent the relation between force and cutting parameters in milling T10 hardened steel, single factor milling experiments with different cutting parameters were done. The experimental result showed that there exited maximum inflection point in force curve under different speeds, and the relation between force and cutting parameters could not be represented with an uniform mathmatical equation. Respective prediction modal of milling force in low speed and high speed were set up using least-square method, which was significant at level of α=0.0005, and its result of R- test was higher than 0.98. This study indicates that the applicable prediction modals in milling T10 steel with low and high speed are different, predict modals being set up can be used to estimate milling force.

Abstract: The thermal-mechanics coupling rule and analytic method of coupling based on principle of cellular automation (CA) have been put forward for the sake of solving coupling effect problem of multi-physics field on the milling insert during milling. The evolution rule of stress function was derived on milling insert according to thermal elasticity by analysis of thermal-mechanics coupling of milling insert based on principle of CA. The temperature change function of the milling insert was deduced in the event of fixed cutting parameter based on heat transfer theory. The local rule of CA on thermal-stress of milling insert was established. The influence factor and distribution regularities of thermal stress were obtained. Compared the numerical-value result of analysis on thermal-mechanics coupling based on principle of CA with analytic result of finite element method(FEM), the effectiveness of CA method was testified. A way of analysis with flexibility was provided for coupling problem of thermal stress field and mechanical stress field for milling insert. The theory basis of research was provided for optimum structural design of indexable milling inserts.