• Proceedings of the KAIS Fall Conference
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• 2008.05a
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• pp.306-308
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• 2008

본 논문은 정면 밀링 가공에서의 절삭력 예측을 위한 수학적 모델을 설정하고 컴퓨터 시뮬레이션을 수행하였다. 실험으로 얻은 절삭력 데이터를 이용하여 비절삭 저항을 모델링하였고 컴퓨터 시뮬레이션을 통해 절삭력을 예측하였다. 예측된 절삭력은 실제 실험을 통해 얻은 절삭력과 비교하여 본 모델의 타당성을 검증하였다.

• Tunnel and Underground Space
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• v.32 no.6
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• pp.386-396
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• 2022

To analyze the influence of variables of roadheaders, the linear cutting testing data of pick cutter were collected from the former literatures. The input factors were set up as uniaxial compressive strength, cutting depth, cutting spacing, attack angle, skew angle, and output factors were determined as specific energy, average cutting force, maximum cutting force, average vertical force, and maximum vertical force. After composing a table of the design of experiment (DOE). The contribution level of each factor was calculated by analysis of variance (ANOVA). As a result, the factors having greatest influence on cutting force and specific energy were uniaxial compressive strength and cutting spacing.

• Transactions of the Korean Society of Mechanical Engineers
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• v.13 no.3
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• pp.424-432
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• 1989

A mathematical model is developed for determination of the dynamic cutting force from static cutting data. The dynamic cutting force is analytically expressed by the static cutting coefficient and the dynamic cutting coefficient which can be determined from the cutting mechanics. The proposed model is verified by the chatter stability charts. A good agreement was shown between the stability limits predicted by the theory and the critical width of cut determined by experiments. The static cutting coefficient dominates high speed chatter stability, while the dynamic cutting coefficient dominates low speed chatter stability.

• Tunnel and Underground Space
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• v.32 no.4
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• pp.243-253
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• 2022

In this study, the cutting efficiency of TBE (Tunnel Boring Extender) was evaluated by using rotary cutting tester. In the rotary cutting test, a specimen which has a drilled hollow hole at the center was made of rock-like material. The specimen was cut by UDC (undercutting disc cutter) with spiral cutting path to simulate the cutting process of TBE. The cutting forces and specific energy were evaluated under different cutting conditions. The results indicated that the cutter forces of UDC linearly increased with the vertical and radial penetration depths. Among the three directional cutter forces, the normal force is larger than other force components. While the specific energy decreased with the two penetration depths, in particular, it was presumed that the specific energy was minimized at a certain value of the ratio of radial to vertical penetration depth.

• Journal of Korean Tunnelling and Underground Space Association
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• v.16 no.6
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• pp.573-584
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• 2014

In this study, the variations of cutter acting forces depending on cutting conditions were examined to obtain basic data for roadheader cutting head design. The linear cutting tests were performed in the condition of different attack angles, penetration depths, cutter spacings by using a slim conical pick for the light cutting condition. Cutter acting forces were measured by 3-directional load cell under different test conditions, and the analysis for cutting performance were carried out after calculating average values of the measured results. It is confirmed that the optimal cutting condition for the mortar specimen is the 50 degree attack angle, the cutter spacing of 12 mm, the cutting depth of 9 mm which are obtained from the analysis results. In addition, 50 degree attack angle is more effective than 45 degree attack angle to design optimal specifications of cutting head.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.1
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• pp.161-182
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• 2018

We carried out a series of linear cutting machine tests to assess the cutting performance of a pick cutter in sedimentary rock. The specimens were Linyi sandstone from China and Concrete (rock-like material, conglomerate). Using the small scaled LCM system, we estimated the cutter force and specific energy under different cutting conditions. The cutter forces (cutting and normal) increased with penetration depth and cutter spacing in two rock types, and it was affected by the strength of specimens. On the other hand, the ratio of the peak cutter force to the mean cutter force was influenced by cutting characteristic and composition of rock rather than rock strength. The cutting coefficient was affected by the friction characteristic between rock and pick cutter rather than the cutting conditions. Therefore, the optimal cutting angle can be determined by considering of cutting coefficient and resultant force of pick cutter. The optimum cutting condition was determined from the relationship between the specific energy and cutting condition. For two specimens, the optimum s/p ratio was found to be two to four, and the specific energy decreased with the penetration depth. The result from this study can be used as background database to understand the cutting mechanism of a pick cutter, also it can be used to design for the mechanical excavator.

• Journal of the Korean Society for Precision Engineering
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• v.8 no.1
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• pp.116-129
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• 1991

A cutting force model for face milling operation using 3-directional specific cutting force coefficients is developed. The model is taken into consideration factors such as cutter geometry, machining conditions, spindle eccentricity, insert initial postion errors, etc. The simulated force in X, Y, Z directions from the model are subsequently compared with measured forces in the time and frequency domains. The simulated forces have a good agreement with measured forces.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1996.10a
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• pp.96-100
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• 1996

So far the analysis and modeling of cutting process is studied commonly assumed as being linear stochastic or chaotic without experimental verification. So we verified force signals of cutting process(ball end-milling) is low-dimensional chaos by calculating Lyapunov Exponents. reconstructing attractor using time delay coordinates and calcula-ting it's fractal dimension.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.5
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• pp.116-122
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• 2008

In order to establish automation or optimization of the machining process, predictions of the forces in machining are often needed. A new model fur farces in milling with the experimental model based on the specific cutting pressure and the Oxley's predictive machining theory has been developed and is presented in this paper. The specific cutting pressure is calculated according to the definition of the 3 dimensional cutting forces suggested by Oxley and some preliminary milling experiments. Using the model, the average cutting forces and force variation against cutter rotation in milling can be predicted. Milling experimental tests are conducted to verify the model and the predictive results agree well with the experimental results.

• Journal of the Korean Society for Precision Engineering
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• v.11 no.4
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• pp.13-25
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• 1994

In order to design and improve a new machine tool, there is a need for a better understanding of the cutting force. In this paper, the computer programs were developed to predict not only the mean specific cutting pressure but also the cutting force. The simulated cutting forces in X, Y, Z directions resulted form the developed cutting force model were compared with the measured cutting forces in the time and frequency domains. The simulated cutting forces resulted from the new cutting force model have a good agreement with the measured force in comparison with these resulted from the existing cutting force model.