May 2023 Volume 5

AUTOMATION

Types of Digital Twins We mentioned earlier that a digital twin involves the virtual modelling of an existing physical entity, system, or process, which includes (often in real time) communication between the two – the digital thread. But it also turns out that you can use a virtual model to design a physical process. In other words, the virtual model precedes the physical product or process. On a broader and more practical scale, digital twin systems can be generally categorized into three types based on how closely they hone-in on their applications and functionalities: • Product Digital Twins are used to simulate and test the design and performance of a physical product before it is manufactured. They enable engineers to analyze and optimize various parameters, such as the product's structure, materials, and components, before actual manufacturing begins. • Process Digital Twins model and optimize manufacturing processes, including assembly lines, supply chains, and logistics. These help manufacturers to simulate and analyze different scenarios, identify potential bottlenecks, and optimize their operations for efficiency and cost reduction. • System Digital Twins model and optimize complex systems, such as buildings, cities, and industrial plants. This is a broader type of digital twin that enables the monitoring and analysis of these systems, identify potential problems, and optimize their operations to improve energy efficiency, reduce environmental impact, and increase safety. What Is the Difference Between a Digital Twin and Computer Simulation? Unquestionably, digital twin technology and simple computer simulation share some similarities, but the two also have some key differences. A digital twin is a virtual model of a physical system or process that simulates its behavior, often in real-time. It uses data from sensors, systems, and other sources to create a digital representation of a physical asset, system, or process. Again, the line of communication between the actual process and the digital twin is called the digital thread. This banter enables engineers/operators to monitor and analyze the behavior of the physical system as it happens and make predictions about future behavior. In contrast, simple computer simulation typically involves the creation of a mathematical or logical model of a system or process that is run on a computer. These simulations are often used to test hypotheses, make predictions, or evaluate different scenarios. There are several ways in which simulation can contribute to the creation of a digital twin of a forging process: • Modelling the process -- Simulation can be used to model the behaviour of the billet being forged and account for its properties such as elasticity, plasticity, and flow behaviour. This allows the simulation to predict how the material will behave under different conditions, such as different temperatures, pressures, and deformation rates.

• Identifying potential issues -- By simulating the forging process, engineers can identify issues that may arise during the actual process, which allows them to adjust it before it is implemented in reality. • Optimizing the process -- Simulation can help optimize the forging process by testing different scenarios and identifying the most efficient and effective way to forge the material. This can reduce costs and improve final product quality. • Real-time monitoring -- Once the digital twin is created, simulation can monitor the forging process in real- or near time, by collecting data from sensors and other sources and comparing it to the virtual model. This digital thread allows engineers to adjust the process on the fly. The main differences between digital twin technology and simple computer simulation are their potential to use real- or near-time data; their increased accuracy and level of detail; their complexity; and their ability to exercise control over the system being modelled. In the interest of relevance, consider that a forging billet is heated before it is transferred to a press for deformation. It can be heated in an induction furnace, or perhaps a gas furnace, but each method heats the workpiece differently. Fortunately, through the technology of optical pyrometry, we canmonitor the temperature of a workpiece in real time through the entire forging process. Tom Ellinghausen, President of Forge Technology, Inc., which represents the QForm-UK metal forming software platform, puts it this way: “In forging, aside from temperature, you can’t always measure all the ‘in process’ parameters in real time, nor track the deformation intensity and rate of every finite element of the workpiece mesh. Although empirical observation can lead to conclusions about the nature of physical deformation, a true and full digital model includes pre- and post-process information, such as the cooling that occurs as a hot workpiece traverses from furnace to press, the shop environment, the use of lubrication, quenching, heat treating and much more.” “A digital twin is a platform that tries to incorporate every element of reality that surrounds a process or a system,” said Ellinghausen. “Those of us in the simulation software business feel that we’ve been dealing with digital twin concepts all along. In recent years, scaling the process up to include pre- and post-forging operations has led to a more encompassing approach to simulation. Today, the term digital twin implies simulation, though on a broader scale. Overall, the use of digital twins in forging can help to reduce costs, improve efficiency, and increase product quality, by providing engineers with a powerful tool for testing and optimizing the forging process.” Digital twin technology is a more advanced and complex form of computer simulation used for the timely monitoring and control of physical systems. While simple computer simulations can be useful for testing hypotheses and making predictions, they are typically not as accurate or detailed as digital twins.

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