利用LS-DYNA分析模擬金屬正交切削切屑形成之研究

The Study of Chip Formation in Othogonal Metal Cutting Using LS-DYNA

王維聖(Wei-Shen Wang)

指導教授 ： 戴兢志

大同大學/工程學院/機械工程學系所/碩士(2004年)

摘要

本研究利用有限元素分析軟體LS-DYNA建立一套金屬正交切削過程的模擬分析模型，並藉由模擬真實的金屬正交切削過程瞭解切屑形成時的應力、應變等物理量的變化，以助於提高成品尺寸精度和改善成品品質。分析模型中使用多線性彈塑性材料的構成方程式來描述材料的行為，並且採用物理條件型的切屑剝離準則作為未變形之切屑是否自工件剝離而形成切屑的判斷準則。完成後的分析模型擬利用真實的切削實驗結果來驗證本研究所建立的準確性，結果顯示有限元素分析結果與實際切削實驗結果的趨勢相同。
本研究顯示，當增加切削速度的情況下，切屑剪切平面之剪切角會隨著切削速度的增加而增加。若固定斜角，增大摩擦係數的情況下，切屑的彎曲度和剪切角會減少，而接觸長度和切削力會變大。若固定摩擦係數，增大斜角的情況下，剪切角也會增大，但切削力和接觸長度會變小，此結果與切削理論的結果相符。

關鍵字

SPH ； LS-DYNA ； 金屬正交切削

並列摘要

This research uses the finite element analysis software LS-DYNA to establish the simulation analysis model of a set of metals orthogonal cutting process, and understand when chip forms physical quantity's change of stress, strain and so on by simulate the real metal orthogonal cutting process, and help to raise the size precision of the finished product and improve the quality of the finished product. Uses the constitution equation of the linear elastio-plastic material in the analysis model to describe the material behavior, and uses the physical condition's chip to separate criterion to be undeformed chip whether separate forms the judgment criterion of the chip from the work piece. Analysis model which after complete to plan to use the real cutting experiment result to confirm the accuracy which this research establishes, the result demonstration finite element analysis result and the tendency of actual cutting experiment result is same. This research demonstration that when in the condition of the cutting speed increase, and the shear plane of the shear angle of chip will be able to increase along with the cutting speed increase. If fix rake angle, and in the situation of enlarge the friction coefficient, then the curve degree of chip and the shear angle will reduce, but contact length and cutting force will change in a big way. If fix the friction coefficient, and in the situation of enlarge the rake angle, and the shear angle also can increase, but the cutting force and the contact length can change slightly, this result and the cutting theory result tallies.

並列關鍵字

LS-DYNA ； Orthogonal Metal Cutting ； SPH

參考文獻

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