The University of Illinois at Urbana-Champaign (UIUC; Urbana, IL) has a long, distinguished history and tradition in mechanical and applied engineering sciences, and the university will soon celebrate the opening of a long-planned, multi-million-dollar expansion to its Mechanical Science and Engineering (MechSE) building.
UIUC has been home to many notable alumni that excelled as entrepreneurs, creating companies such as Netscape, Advanced Micro Devices, PayPal, Oracle, Lotus Software, YouTube, and Tesla Motors, to name a few.
As part of the face-lift, UIUC’s Transform MEB (Mechanical Engineering Building) program includes a $12 million donation from alumnus Sidney Lu (BSME ‘81), chairman and CEO of computer and smartphone manufacturer Foxconn Interconnect (Taiwan), which builds Apple iPads and iPhones.
The east wing addition will be known as the Lu Center for Learning and Innovation. This project includes a five-story addition to the east of the MEB, a single-story addition to the north, and 66,000 ft² (20,117 m²) of existing space re-imagined, re-engineered, and optimized for education, innovation, and community, according to UIUC.
Besides the expansion, in October 2017 UIUC MechSE announced that the university was awarded a Materials Research Science and Engineering Center (MRSEC) by the National Science Foundation, with the center supported by a six-year, $15.6-million grant focusing on new nanomaterials. This announcement followed the NSF awarding UIUC $18.5 million for a new NSF Engineering Research Center led by MechSE Professor Andrew Alleyne. That center, called the Power Optimization for Electro-Thermal Systems (POETS), focuses on the thermal and electrical challenges surrounding mobile electronics and vehicle design as a single system.
“We want to increase the total power density in vehicles by 10 to 100 times. That would translate into billions of liters of fuel saved and nearly double an electric car’s range,” said Alleyne, the Ralph & Catherine Fisher Professor in MechSE, in an statement. “Today’s electrical technologies are at their thermal limit. A systems approach is the only way we’ll push beyond the current state of the art.”
In a recent discussion with Manufacturing Engineering, UIUC’s Placid Matthew Ferreira, Tungchao Julia Lu Professor and the former MechSE department head, and Shiv Gopal Kapoor, Grayce Wicall Gauthier Chair and professor of mechanical science and engineering, described the broad-based scope of research at the department.
“We are called MechSE, for Mechanical Science and Engineering, because some time ago the mechanical engineering department and the theoretical and applied mechanics department joined together,” Ferreira said. “The department spans mechanical sciences and mechanical engineering, going from the more fundamental—the theoretical basis for mechanical engineering such as mechanics, transport phenomena, solid mechanics, fluid mechanics, control theory, kinematics, dynamics—to more applied areas such as IC engines, mechatronics, air conditioning and refrigeration, robotics, manufacturing processes, manufacturing systems, biomechanics, and materials behavior.
“It’s a very wide group, and in this ecosystem of mechanical sciences and engineering, manufacturing plays a rather important role, both from the manufacturing processes aspects and the manufacturing systems aspects,” Ferreira continued. “We tap into the theoretical expertise within the department in things like solid mechanics, solidification processes in terms of dynamics and controls. We bring those things down into modeling or manufacturing processes, design of machine tools, and control of manufacturing processes. We even go into cloud manufacturing. We take the computational sciences aspects and get into the simulation of manufacturing processes.”
This broad approach takes advantage of the expertise in the department, encompassing various manufacturing disciplines, such as computational fluid dynamics for process modeling and simulation, Ferreira added. “[This helps us] understand the material behavior when we are looking at the machining process, for example, and also where we are heading in these areas on the manufacturing systems cloud; we call it cyber systems.”
Cloud and Cyberphysical Manufacturing Advances
With UIUC’s history of computer research and simulation resources, the department can leverage the availability of supercomputer power, located both at the university campus and elsewhere in the US. The university hosts the National Center for Supercomputing Applications (NCSA), which created Mosaic, the first graphical Web browser.
“When you come to Illinois, you realize that with its history, it’s had a very long contribution to manufacturing from researchers who did the first analyses of thermal aspects in machining,” said Kapoor, noting the importance of such experiments on cutting tools and on the thermal science of the machining process. Kapoor, editor-in-chief of the Journal of Manufacturing Processes, Ferreira and other professors at Northwestern University (Evanston, IL) have three ongoing projects with the Digital Manufacturing and Design Innovation Institute (DMDII; Chicago) at the UI Labs.
“In one project, we’re developing what’s known as an operating system for cyberphysical manufacturing,” Ferreira said. “In another project, we are working with Caterpillar and Missouri Science and Technology to reduce variability of machining processes. And then in a third project, we’re developing a framework for uncertainty quantification and uncertainty reduction in die-casting processes.”
In the case of the cyberphysical operating system project, Ferreira said the group is only about a year into the research but its leaders have begun asking others to bring in their machine tools to work with the operating system.
Collaborating with industry pays off immensely in advancing research and getting new technologies into the market. “We’re working with industrial partners, like Caterpillar and others, on so many levels,” said Ferreira, citing the major contributions of earlier researchers at UIUC, such as B.T. Chao, Kenneth Trigger, Klaus J. Weinmann, Subbiah Ramalingam, and more recently, Shiv Kapoor. “They created things that were widely used in industry, tangible models of machining processes that industry could actually apply and use and try to figure out what forces to expect during machining and how different errors would expose themselves through the process mechanics to the surface finish.”
Much of the university research started with solving problems encountered by automotive suppliers and OEMs. “We started the work with Ford, GM, and their suppliers,” he said. “We also have Caterpillar, John Deere, and then the machine tool builders, very early working with Ingersoll, the milling machine company, DMG Mori and others.”
For about 12 years, the UIUC department also ran a center focusing on machining and machine tool systems. Ferreira was director of the Nanoscale Chemical-Electrical-Mechanical Manufacturing Systems-NSF Nanoscale Science and Engineering Center (Nano-CEMMS), from 2003-2010, and he is currently an affiliate of the Micro-Nanotechnology Laboratory at UIUC.
“We transitioned from there to the micro and the nano manufacturing era, where Illinois has been a leader,” Ferreira said. “We had a fairly large center that specifically set out to define all manufacturing at the nanoscale, and we took a lot of processes down to micromachining, microforming, and micro EDM.”
—Senior Editor Patrick Waurzyniak
Tech Papers from SME Journals and Manufacturing Letters
These summaries, excerpts, and web links are from recent papers published in the SME Journal of Manufacturing Systems, Journal of Manufacturing Processes, and Manufacturing Letters, which are printed by Elsevier Ltd. (www.elsevier.com) and used here with permission.
Chatter Avoidance in Robotic Milling
In their article, “CCT-based mode coupling chatter avoidance in robotic milling,” Lejun Cen and Shreyes N. Melkote of the George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology (Atlanta), examine issues with chatter generated by robotic milling. Their paper, which is published in Volume 29 of the Journal of Manufacturing Processes, is available at https://www.sciencedirect.com/science/article/pii/S1526612517301573#fig0035.
Currently, large aerospace structures are machined using large multi-axis CNC machining centers. In comparison, milling with a multiple degree-of-freedom (DOF) articulated robotic arm has several advantages due to its lower cost and versatility. The low stiffness of an articulated arm robot, however, gives rise to severe low frequency mode coupling chatter during machining.
Previous studies have shown that such chatter can be suppressed by minimizing the angle between the average resultant cutting force direction and the direction of maximum principal stiffness of the robot. This approach limits the range of permissible robot motion, and therefore its flexibility of use. This paper presents a new method for avoiding mode coupling chatter in robotic milling using the Conservative Congruence Transformation (CCT) stiffness model, which does not require changing the tool feed direction or the workpiece orientation. Robotic milling experiments show that mode coupling chatter is significantly reduced when using this approach.
Milling of large aircraft parts is routinely performed using large and expensive CNC machining centers that are very rigid and accurate. These machine tools often occupy a large workspace on the factory floor. In contrast, a multi-axis articulated arm based robotic milling system offers a high degree of flexibility for machining of large aircraft parts. Prior work has shown that, compared to industrial CNC machining centers, robotic milling systems can reduce production workspace requirements by 40% and simultaneously provide greater flexibility. Robotic milling is also more suitable in hazardous environments. However, practical applications of articulated arm robots are often restricted to low force applications such as material handling, assembly, welding, and deburring.
Finish Turning Ti-6AL-4V with Atomization-Based Cutting Fluid
New atomization cutting fluid spray systems hold potential to improve rough turning of titanium, which is discussed in the paper, “Finish turning of Ti-6Al-4V with the atomization-based cutting fluid (ACF) spray system,” by authors Chandra Nath and Shiv G. Kapoor of the Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign (UIUC; Urbana, IL), and Anil K. Srivastava of the University of Texas Rio Grande Valley (Edinburg, TX). The article, published in Volume 28 of the Journal of Manufacturing Processes, is available at https://www.sciencedirect.com/science/article/pii/S1526612517300853#fig0020.
Product quality and productivity are important factors in manufacturing industries, especially when dealing with cumbersome materials like titanium. Cooling and lubrication effects offered by the associated metalworking fluid application system play a vital role in determining these factors, especially during finish cutting. Recently, the ACF spray system has shown promising cooling and lubrication effects during rough turning of titanium at the macro–scale, but has yet to be examined during finish cutting (e.g., depth of cut and feed rate 0.2 mm or lower).
This paper aims to study the effect of the ACF spray system on machining performance during finish turning of Ti-6Al-4V. In the first set of experiments, two spray parameters (viz., gas velocity and flow rate) and cutting parameters (viz., cutting speed, feed rate and depth of cut) are varied to select the most suitable condition for the application of the ACF spray system. Machining outputs are evaluated in terms of nose wear, cutting temperature, surface roughness, roundness error, chip morphology, and part hardness. A separate set of experiments is then performed to compare the performance of the ACF spray system against compressed air (dry) and flood coolant conditions. It is found that, even at a lower fluid flow rate of 1.5 mL/min (10% volume) at a lower gas velocity, the spray system outperforms the other two coolant conditions, thus further enhancing the performance of an environmentally-friendly manufacturing process.
Modeling Recovery of Rare Earth Magnets
In their paper, “Modeling operation and inventory for rare earth permanent magnet recovery under supply and demand uncertainties,” authors Hongyue Jin and Yuehwern Yih, of Industrial Engineering, Purdue University (West Lafayette, IN), and John W. Sutherland of Environmental and Ecological Engineering at Purdue, discuss the factors involving inventory strategies using modeling simulations.
Rare earth permanent magnets (REPMs) play an essential role in various applications, such as renewable energy production and aerospace and defense related products. Rare earth elements (REEs) such as neodymium and dysprosium are used in REPMs, and the supply of these REEs has experienced volatility. To mitigate this risk, REEs may be recovered from end-of-life (EOL) products such as computer hard disk drives (HDDs).
This paper develops an operation and inventory management strategy to explore the profitability under uncertain market supply and with varying values whose demand also faces significant uncertainties. The paper appears in the January 2018 issue, Vol. 46, of the Journal of Manufacturing Systems, and is available at https://www.sciencedirect.com/science/article/pii/S0278612517301437.
TechFront is edited by Senior Editor Patrick Waurzyniak.