Jinn-Jong Sheu

Prof. Dr. Jinn-Jong Sheu

National Kaohsiung University of Science and Technology, Kaohsiung, Taiwan

Research Focus & Metrics

Academic Career Length

19Years (2008-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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22 November 2008 in The International Journal of Advanced Manufacturing Technology
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Journal Article
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JSJinn-Jong Sheu
Jinn-Jong Sheu
CYCheng-Hsien Yu
Cheng-Hsien Yu

25 April 2020 in Metals
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Journal Article
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TTTAT TAI TRUONG
TAT TAI TRUONG
Quang-Cherng HsuQuang-Cherng Hsu
Quang-Cherng Hsu
VTVan-Canh Tong
Van-Canh Tong
JSJinn-Jong Sheu
Jinn-Jong Sheu
In this study, porthole die used for extrusion of a solid heatsink profile with wall thickness variation ratio up to 15.3 was designed using finite element (FE) simulations. To improve the flow balance in the die, a design approach was introduced to find the appropriate die structure, which includes the porthole and pocket geometry correction, the bearing length adjustment, and the port bridge structure modification. Using the proposed die, the predicted velocity relative difference (VRD) and the maximum velocity difference (ΔV) of extrudate were significantly lower than those of an initial die, which was preliminarily designed based on general design experiences. The required extrusion force and the residual stress in the product were also reduced significantly. Then, the effects of the port bridge structure and welding chamber height on the behavior of the metal flow in the die were investigated. To verify the proposed die design, experimental extrusions were conducted on a 930-ton extruder. The experiment results showed that the extruded product fulfilled the requirements for dimensional tolerances. The design approach presented in this paper can be useful for practical implementation of die design when extruding similar solid heatsink profiles with large wall thickness variation.

1 October 2019 in IOP Conference Series: Materials Science and Engineering
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JSJinn-Jong Sheu
Jinn-Jong Sheu
BWBao-Shan Wang
Bao-Shan Wang
Wire drawing is a common used process to reduce the diameter of a small rod or a wire. The parameters of drawing die design such as die angle, bearing length, entrance fillet, and the drawing ratio of each pass are crucial to control the quality of a drawn wire. Taguchi method was adopted to optimize the drawing die geometry design. The lubrication conditions were taken into consideration to observe the effect of friction on the dimension accuracy of the drawn wires. The optimum combination of the drawing die design using 20% of reduction ratio is semi die angle 9 degrees, bearing length 1.2mm and entrance fillet 0.4mm. Two types of aluminum alloy 1070 and 1050 were tested using lubricants sodium sulfide (Na2S), graphite, and drawing oil, respectively. The lubrication effect of sodium sulfide is the best to achieve the lowest drawing load. The lubricant Na2S had the best performance in terms of lowest maximum drawing force for both of A1050 and A1070. The final diameters of the drawn wires were very close to the specification 4.0 mm. The CAE simulations were able to find the optimum design of die. The designed drawing machine was capable of carrying out the experiments and obtains consistent results.

23 June 2022 in Metals
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Journal Article
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JSJinn-Jong Sheu
Jinn-Jong Sheu
CHChien-Jen Ho
Chien-Jen Ho
CYCheng-Hsien Yu
Cheng-Hsien Yu
CKChi-Yuan Kao
Chi-Yuan Kao
A Bézier curve groove-shape roll design method was proposed and compared to round-oval-round designs for the wire rolling process. CAE simulations were adopted to predict the rolling forces and torques required for the rolling process. The rolling torque required for the case of 28% vertical compression rate is 73% higher than the case of 12% compression rate. The curve fittings of the rolling torque and the compression force with respect to the compression rate were obtained with very high R-square values (0.99 and 0.98) in the first rolling pass. The rolling force required for the Bézier curve groove-shape design is no different compared to the oval design with the same compression rate, but the rolling torque requirement for the next rolling station is 6% less than the oval groove design. Furthermore, the equivalent strain distribution on the cross section of the product was uniform, and no fin flash defects occurred. The proposed Bézier curve groove-shape is a better design from the viewpoint of uniform product mechanical property requirement, and a larger compression rate per pass could be achieved.


4 July 2025 in Manufacturing Technology
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Journal Article
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JSJinn-Jong Sheu
Jinn-Jong Sheu
ECEn-Hsuan Chien
En-Hsuan Chien
This study examines the two-pass hot rolling process of 6061 aluminum alloy wire, focusing on forming load measurement to evaluate process stability and its effects on dimensional accuracy and mechanical property uniformity. Using response surface methodology (RSM), process parameters and forming loads were analyzed to assess their influence on mechanical property distribution and verify the applicability of load measurement in process quality evaluation. A full-factorial finite element simulation was conducted to investigate the effects of pre-forming section reduction rate, material temperature, roll speed, and friction coefficient. Experimental results indicate that forming load measurements effectively capture variations in initial wire temperature and reveal the influence of material velocity and roll speed. Load data also identify the spike phenomenon caused by improper roll positioning, leading to abnormal load surges and reduced mechanical property uniformity. The strong agreement between experimental forming loads and FEM simulations validates the reliability of the proposed measurement method. This study provides a basis for wire rolling process design and machine learning-based quality prediction, supporting advancements in smart manufacturing applications. Two pass wire rolling Bézier curve groove-shape design Aluminum alloy 6061