Jiayu Ye

I am Jiayu Ye, a second-year PhD candidate at RMIT University. I received my Bachelors degree and Masters degree in Mechanical Engineering from Beijing University of Technology (BJUT) in 2014 & 2017, respectively.

The research areas I’m interested in include (but are not limited to) additive manufacturing, micro-machining, control algorithms & machine learning.

Skills

  • Autodesk Inventor
  • SolidWorks
  • MATLAB
  • B&R Automation Studio
  • Python
  • Image processing

PhD Project

Topic: PhD, In situ Visual Monitoring of Laser Metal Deposition for Additive Manufacturing

Additive manufacturing (AM) has been widely used in aerospace, medical implant and other industry sectors in recent years due to its extraordinary capability of net-shape building of parts with complex geometries.

As a member of the AM category, laser metal deposition (LMD) is a superior technology for repair, coating and refurbishment. Following its name, the mechanism of LMD is that metal powders are heated by a laser beam and become molten, after which they are blown from a nozzle. The molten metal drops are then directly deposited and solidified onto the surface of the substrate along the laser scanning path, which builds the part layer by layer. However, this technology still faces many challenges despite its inherent advantages. System inputs such as heat input rate and scanning speed are usually set empirically. If they are set inappropriately, defects (e.g. porosity and cracking) will occur and cause the failure of the part and material wastage. In recent years, many researchers are focusing on in situ monitoring of the process signatures (e.g. melt pool temperature and size) to characterise the impacts of the chosen values for the system inputs. But after measuring these signatures, what do they mean for final product qualities? Are there enough signatures to be monitored? This unclear relationship between the process signatures and the final product qualities is the most challenging problem in AM. Therefore, the aims of my research are to (i) determine if there is other process information that relates to product quality, and (ii) build the bridge between the family of process signatures and the final product qualities using a data-driven method.

Figure 1: Experimental set up of laser metal deposition system

Figure 1

Experimental set up of laser metal deposition system

Figure 2: An example of the cross-section of stainless steel 316L multi-track cladding. The lack-of-fusion defects occur at the bottom between neighbouring tracks.

Figure 2

An example of the cross-section of stainless steel 316L multi-track cladding. The lack-of-fusion defects occur at the bottom between neighbouring tracks.

Prior Work

My undergraduate research was on controller design for vibration suppression of drive systems. I designed an Integral Proportional (IP) feedback controller and a zero-vibration shaper for an uncertain two-mass torsional system. The key feature was that all the information the controller parameters need is extracted from only the motor speed using time-frequency analysis.

My previous research topic was ‘Design & Implementation of a Spatial Biomimetic Adhesive Device’. Unlike traditional grappling devices that use ‘fingers’ to grasp objects, the adhesive device can grasp the object by sticking to its surface with a little preload. Furthermore, the device can release the object without any damage to its surface.

Publications

  • Cui, J., Ye J. & Chu, Z., 2018. 'IP controller design for uncertain two-mass torsional system using time-frequency analysis', Shock and Vibration, vol. 2018,  pp. 1-9. https://doi.org/10.1155/2018/1329876.
  • Ye, J., Cui, J. & Chu, Z., 2016. ‘Experimental study of vibration suppression for uncertain two-mass torsional system’, 2016 12th IEEE International Conference on Control and Automation (ICCA), Kathmandu, Nepal, 1-3 June 2016, pp. 996-1001. https://doi.org/10.1109/icca.2016.7505410.
  • Ye, J., Chu, Z. & Cui, J., 2017. ‘Optimization design of micro stroke table for gecko adhesives actuating’, 2017 IEEE 17th International Conference on Nanotechnology (IEEE-NANO), Pittsburgh, Pennsylvania, USA, 25-28 July 2017, pp. 330-333. https://doi.org/10.1109/nano.2017.8117312.

Further Information

Supervisors

  • Professor Ivan Cole (RMIT University)
  • Professor Alireza Bab-Hadiashar (RMIT University)
  • Professor Reza Hoseinnezhad (RMIT University)

Collaborator

  • Dr Nazmul Alam (CSIRO Manufacturing Flagship)

Discover more

aboriginal flag
torres strait flag

Acknowledgement of country

RMIT University acknowledges the people of the Woi wurrung and Boon wurrung language groups of the eastern Kulin Nation on whose unceded lands we conduct the business of the University. RMIT University respectfully acknowledges their Ancestors and Elders, past and present. RMIT also acknowledges the Traditional Custodians and their Ancestors of the lands and waters across Australia where we conduct our business. - Artwork created by Louisa Bloomer